जुनी पेन्शन बाबत

1/3/2024

जूनी पेन्शन बाबत

जूनी पेन्शन योजना लागू होण्यासाठी महाराष्ट्र राज्य शिक्षक परिषदेनै..2010 पासून 38आंदोलनै केली... नागपूर चा12 डिसेंबर  2023 चा मोर्चा अभूतपूर्व होता त्यात शिक्षक‌ परिषदेचा प्रचंड संख्येने सहभाग होता.....आज पेन्शन बाबत सकारात्मक विषय सरकार करते आहे.शिक्षक आमदार नागो गाणार यांनी शिक्षकांना जो पर्यंत पेन्शन मिळत नाही तोपर्यंत मी पेन्शन घेणार नाही म्हणून  स्वताची पेन्शन नाकारली...... मुंबई शिक्षक परिषदेने मार्च 2023 ला मुंबईत 6 दिवस संपात भाग घेऊन निदर्शने केली..... त्यामुळे पेन्शन साठी अभयास गट नेमला होता.त्यांनी नोव्हेंबर  ला  सरकला रिपोर्ट सादर केला...पण 12 डिसेंबर 2023 ला अभूतपूर्व मोर्चा मुळे या रिपोर्टवर कारवाई सुरू झाली...आज काही प्रमाणात शिक्षक परिषदेला यश मिळाले असे म्हणू शकतो.शासन अधिक सकारात्मक झाले आहे.पण आज  सरकारने पेन्शन जी‌ घोषणा केली त्या बाबत प्रत्यक्ष जी आर आला की अभ्यासपूर्ण विवेचन व नक्की काय आहे ?हे महाराष्ट्र राज्य शिक्षक परिषद खुलासा करेल..थोडी वाट पाहू.....

पण लढाईत आपण एक पाऊल अजून पुढे टाकले आहे..

जय शिक्षक परिषद

आपला नम्र

शिवनाथ दराडे.

महाराष्ट्र राज्य शिक्षक परिषद मुंबई कार्यवाह

Std. 5 Math Practice Paper

Human Body and Organ system

Question 1:

Find out my partner.

Group 'A'	Group 'B'
1. Heart beats	a. 350 ml
2. RBC	b. 7.4
3 WBC	c. 37∘C
4 Blood donation	d. 72
5 Normal body Temperature	e. 50-60 lakh/mm3
6 pH of oxygenated blood	f. 5000-6000 per mm3

ANSWER:

Group 'A'	Group 'B'
1. Heart beats	d. 72
2. RBC	e. 50-60 lakh/mm3
3 WBC	f. 5000-6000 per mm3
4 Blood donation	a. 350 ml
5 Normal body Temperature	c. 37∘C
6 pH of oxygenated blood	b. 7.4

Question 2:

Complete the following table.

Organ system	Organs	Functions
1. Respiratory
2. Circulatory system

ANSWER:

 

Organ system	Organs	Functions
1. Respiratory	Nose Pharynx Wind pipe Lungs	Traps dust particles and microbes and prevents their entry in the respiratory system. Acts as a passage for the entry of air into the wind pipe. Acts as a passage through which air passes into the lungs. Exchange of gases occurs in lungs.
2. Circulatory        system	Heart Blood vessels	The main organ from where circulation of blood to different body parts occurs. Closed system of vessels which help in circulation of blood.

Question 3:

Draw neat and labeled diagrams.
a. Respiratory system
b. Internal structure of heart.

ANSWER:

a. Respiratory system




b. Internal structure of heart

Question 4:

Explain with reasons.
a. Human blood is red colured.
b. Upward and downward movement of diaphragm occurs consecutively.
c. Blood donation is considered to be superior of all donations.
d. person with 'O' blood group is considered as 'universal donor'
e. Food must have limited amount of salts.
 

ANSWER:

a. Human blood is red in colour due to the presence of the respiratory pigment haemoglobin. Haemoglobin is a pigment which is red in colour and thus imparts red colour to the blood.

b. Diaphragm is a muscular partition which is present between the thoracic cavity and abdominal cavity. During the process of breathing, the upward and downward movement of diaphragm occurs simultaneuosly. When we inhale, the ribs rise up while the diaphragm lowers down simulatenously causing a decrease in pressure on lungs. This results in the moving of air into lungs through nose. As the ribs return to their original position, diaphragm rises up leading to the increase in pressure inside the lungs. This results in moving of the air outside the nose.

c. Blood donation is considered superior of all donations because it can save someome's life. Most of the lives are lost due to blood loss during surgeries, accidents or cases where regular blood transfusion is required. These lives can be saved, if adequate amount of blood is available.

d. Person with 'O' blood group is considered as 'universal donor' because such an indivisual can donate blood to a person having any other blood group.

e. Food must have limited amount of salts as we require limited amounts of these in our body. Excessive salts in food can lead to accumulation of water in different parts of the body such as arms, legs etc. and lead to edema. Too much salt leads to increase in the blood pressure as well.

Question 5:

Answer the follwing questions in your own words.
a.Explain the functional correlation of circulatory system with respiratory, digestive and excretory system.
b.Explain the structure and function of human blood.
c.Explain the importance and need of blood donation.
 

ANSWER:

a. The functional corelation between circulatory system with respiratory, digestive and excretory system is as follows:

We already know that during respiration exchange of gases occurs in the lungs. The respiratory system causes the diffusion of oxygen into the blood and the diffusion of CO₂ out of the blood. The oxygen is then transported to cells of the body via the circulatory system. 
The digestive system is responsible for producing nutrients by breaking complex molecules into simpler ones. The circulatory system then tranports these nutrients to different cells and tissues. 
The excretory system is responsible for the elmination of waste products from the body. These waste products are transported by blood to the excretory system.


b. Blood is a fluid connective tissue that flows in blood vessels. It is composed of two components- plasma and blood cells. 

Plasma is a yellowish colour fluid, made up of water (~90%) and some dissolved nutrients, proteins, hormones and waste products. 

Blood consists of three types of blood cells. These are

i. Red Blood Cells: They contain a red pigment called haemoglobin, which transports oxygen to all body cells.

ii. White Blood Cells: They fight against germs that enter the body. Thus, they protect the body from diseases.

iii. Platelets: When we get injured, bleeding stops after some time. This happens because of the activity of platelets, which help in the clotting of blood.

Functions of blood:

• It transports nutrients and oxygen to the different parts of the body.

• It also carries waste materials (from the different parts of the body) to be removed by the excretory organs.

• Chemical messengers like hormones are transported by the blood.

• Protects the body from disease carrying germs.

• Helps to maintain a constant body temperature.

c. Blood donation is one of the biggest donations of an inidivisual towards their society. Blood loss can occur under circumstances of accidents, during surgeries or in case of diseases which require blood transfusion. Adequate amount of available blood can save many lives. It does not harm or effect the body of the donor and the amount of blood which is donated is recovered within 24 hrs.
This donated blood can be stored and used as and when the requirement arises.

 

Question 6:

Explain the differences.
a. Arteries and veins.
b. External and internal respiration

ANSWER:

a. 

External respiration	Internal respiration
1. It occurs between the body and external environment.	It occurs at the cellular level.
2. It is a mechanical process.	It is a chemical  process.
3. It can be both- voluntary and involuntary action.	It is only an involuntary action.

​
b. 

Arteries	Veins
1. Carries blood towards organs and away from heart.	Carries blood towards heart and away from organs.
2. Carries fully oxygenated blood	Carries deoxygenated and CO2 enriched blood.
3. Blood flows with high pressure and jerks,.	Blood flows with low pressure and smoothly.
4. Have no valves	Have valves to prevent backflow of blood.
5. Walls are elastic.	Walls are non-elastic.
6. Are Deeply placed.	Are superficial.
7 Branched and decreases in size.	Unites and increases in size
8. Can constrict and dilate	Cannot constrict.
9. Have thick and muscular walls	Have thin and less muscular walls.
10. Smallest artery is called arteriole	Smallest vein is called Venules.

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Question 7:

Which health parameters of blood donor should be checked?
 

ANSWER:

The following parameters of blood donors have to be checked prior blood donation:
 

1. Age – There is a set age before which and after which blood donation can be done or not respectively.​
 

2. Weight – Weight of individuals is also an important factor as underweight indivisuals are not allowed to donate blood. In underweight indivisuals, the likelihood of having a reaction such as dizziness and fainting following donation are higher.

3. Heart, lung, and blood disease – Donors are enquired about any prior history of heart, lung, or blood diseases. People with heart disease, heart valve conditions, irregular heartbeat, disease of the blood vessels in the brain, heart failure, and certain lung conditions may be excluded from blood donation. Certain blood diseases such as iron deficiency anemia or chronic leukemia may also lead to exclusion.

4. Other medical conditions – Any other medical condition such as diabetes, hypertension, hypotension, fever etc. are also checked before blood donation.

5. Recent surgery – People with recent surgery are not allowed for donating blood. However, after an year of surgery they can donate blood but only if healing is complete and they have resumed full activity.

6. Pregnancy – Women who are pregnant are not permitted to donate blood during pregnancy and for six weeks after the pregnancy ends.

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Question 8:

Fill in the blanks using appropriant words given in the bracket.
( hemoglobin, alkaline, diaphragm, red bone marrow, acidic, voluntary, involuntary.)

a. RBCs of the blood conatin _________, an iron compound.

b. ____________ is present between thoracic and abdominal cavity.

c. Cardiac muscles are_______

d. pH of oxygenated blood is________

e. Production of RBCs occurs in__________

ANSWER:

​a. RBCs of the blood conatin hemoglobin, an iron compound.

b. Diaphragm is present between thoracic and abdominal cavity.

c. Cardiac muscles are involuntary.

d. pH of oxygenated blood is alkaline.

e. Production of RBCs occurs in red bone marrow.

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Question 9:

Find odd one out.
a. A, O, K, AB, B.
b. Blood plasma, platelets, blood transfusion, blood corpuscles.
c. Trachea, alveoli, diaphragam, capillaries.
d. Neutrophils, globulins, albumins, prothrombin.            

ANSWER:

a. A, O, K, AB, B - K is the odd one out because it is an inorganic ion while rest of the four are types of blood groups.
b. Blood plasma, platelets, blood transfusion, blood corpuscles- Blood transfusion is the odd one out because it is a techniques for transfer ing of blood from donor to repeient. Rest of the three are components of blood.
c. Trachea, alveoli, diaphragam, capillaries- Capillaries are the odd one out because they are a part of the circulatory system while rest of the three are parts of the respiratory system.
d. Neutrophils, globulins, albumins, prothrombin- Neutrophils are the odd one out because they are a type of blood cell. Rest of the three are components of the plasma.         

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Question 10:

Read the following paragraph and identify the disease.

Today, her child became one and half year old. However, that child does not seem to be healthy and happy. It was continuously crying and gradually becoming weak. It has shortness of breath. Its nails have become blue.

ANSWER:

From the above mentioned symptoms, it seams like the child is suffering from some kind of respiratory disorder/circulatory disorder. He has problem in breathing and his nails have become blue which means there is low level or lack of oxygen circulating in the red blood cells. It is known as cyanosis.
It occurs when enough oxygen is not present in blood, thus making the skin or membrane below the skin turn purplish-blue.

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Question 11:

Your neighboring uncle has been diagnosed with hypertension. what should he do to keep hsi blood pressure within normal range?

ANSWER:

The following methods can be adopted to keep the blood pressure within normal range:

• loose the extra weight
• exercise or do yoga regularly
• eat a healthy balanced diet containing fruits and vegetables
• reduce the amount or salt in food
• avoid alcohol and smoking
• reduce the amount of stress by indulging in your favourite activities
• regular monitoring of blood pressure 

Std.7 Ch. 12 Muscular system and Digestive system

Question 1:

Fill in the blanks with the right word from the brackets.
(a) The process of digestion starts from the ............. . (stomach / mouth)
(b) Eyelids have ............. muscles (voluntary / involuntary)
(c) ............ is not a function of the muscular system. (production of blood cells / Performing movements)
(d) Muscles of the heart are .............. (ordinary muscles / cardiac muscles)
(e) Pushing forward the food that has been chewed is the function of the ............. . (stomach / oesophagus).

ANSWER:

(a) The process of digestion starts from the mouth.
(b) Eyelids have voluntary muscles.
(c) Production of blood cells is not a function of the muscular system. 
(d) Muscles of the heart are cardiac muscles.
(e) Pushing forward the food that has been chewed is the function of the oesophagus.​
 

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Question 2:

Find a match for me.

Group 'A'	Group 'B'
(1) Cardiac muscles	(a) always function
(2) Are brought about by muscles	(b) we never feel tired.
(3) Pepsin	(c) uncontrolled and painful contraction of muscles.
(4) Cramps	(d) chewing movements of jaws.
(5) Skeletal muscles	(e) enzyme of the gastric juice.

ANSWER:

​

Group 'A'	Group 'B'
(1) Cardiac muscles	(b) we never feel tired.
(2) Are brought about by muscles	(d) chewing movements of jaws.
(3) Pepsin	(e) enzyme of the gastric juice.
(4) Cramps	(c) uncontrolled and painful contraction of muscles.
(5) Skeletal muscles	(a) always function

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Question 3:

Who is telling a lie ?

Organ	Statement
1. Tongue	My taste-buds can tell only a sweet taste.
2. Liver	I am the largest gland in the body.
3. Large intestine	I am 7.5 meter long.
4. Appendix	Digestion is impossible without me.
5. Lung	I play an important role in excretion.

ANSWER:

The tongue, large intestine, appendix and lungs are lying.

1. Tongue can taste salt, sweet and bitter tastes.
2. Large intestine is 1.5 meter long.
3. Appendix is not required for digestion.
4. Kidneys play an important role in excretion.

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Question 4:

Give reasons.
(1) Food becomes acidic in the stomach.
(2) Cardiac muscles are said to be involuntary muscles.
(3) Intoxicating substances should not be consumed.
(4) Your muscles should be strong and efficient.

ANSWER:

a. Food becomes acidic in stomach because of the presence of hydrochloric acid in the stomach. As the food reaches the stomach, it gets mixed with the hydrochloric acid present there. The hydrochloric acid plays the following roles in digestion:

1. It initiates protein digestion by activating the conversion of pepsinogen to pepsin.

2. It provides acidic medium for the activity of pepsin and other enzymes present in gastric juice.

b. Cardiac muscles are said to be involuntary because they are not controlled by our will. These muscles are found in heart and are the only muscles which work throughout the life without getting tired or fatigue.

c. Intoxicating substances should not be consumed because they harm the body directly or indirectly. Substances such as alcohol cause damage to the nervous system and the digestive system as well. Liver is the main organ which is affected by alcohol. Tobacco is one of the leading causes of oral cancer. Smoking has a direct effect on the respiratory system of an individual and can lead to lung cancer as well.

d. Our muscles should be strong and efficient because they carry out various vital functions in our body. From helping us to breath, digest food to helping us in walking and lifting weights, muscles play an important role. If our muscles are not strong enough we would get tired easily and feel fatigue. It is required to keep them in a healthy state by regular exercising and taking proper diet. 

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Question 5:

Answer the following.
(a) How many types of muscles are there? Which are those types?
(b) What causes the problem of acidity? What is its effect on the body?
(c) Name the different types of teeth. What is the function of each type?

ANSWER:

a. There are 3 types of muscles:

• Skeletal muscle fibre: They are found attached to the skeletal bones and are voluntary. Skeletal muscle fibres are striated and are bundled together in a parallel manner by a sheath of tough connective tissues.

• Smooth muscle fibres: They are present in the walls of internal organs such as blood vessels, stomach, etc., and are involuntary. Smooth muscle fibres are fusiform (taper at both ends) and non- striated. They are held together by cell junctions and are bundled together in a sheath of connective tissues.

• Cardiac muscle fibres: This is the only type of muscle present in the heart. They are contractile in nature and are involuntary. Plasma membranes of cardiac cells are fused together by cell junctions, and hence, the cells stick together. Communication junctions present as intercalated discs facilitate the contraction of cardiac cells as a unit.

b. Stomach contains special cells called oxyntic or parietal cells which secrete hydrochloric acid in stomach. It plays two important roles like:

1. It initiates protein digestion by activating the conversion of pepsinogen to pepsin.

2. It provides acidic medium for the activity of pepsin and other enzymes present in gastric juice.

However, if the level of this HCl exceeds its normal levels, it results in acidity/acid reflux. Higher levels of HCl can result in the following effects on the body:

1. burning sensation in the stomach
2. burning sensation in the throat and heart
3. difficulty in swallowing
4. regurgitation
5. restlessness
6. belching
7. nausea
8. prolonged sour taste in the mouth
9. indigestion

Exposure to higher levels of HCl for longer durations can also result in the development of peptic ulcers/ulcers in the stomach. 


c. There are 4 types of teeth which are found in humans:

1. Incisors are the teeth present at the front portion of the mouth. There are four incisors in each jaw. They are used for biting and cutting food.
2. Canines are located next to the incisors. There are two canines in each jaw. They are used for tearing and piercing food.
3. Premolars lie next to the canines. There are four premolars in each jaw. They are used for chewing and grinding food.
4. Molars lie next to the premolars at the end of the jaw. There are six molars in each jaw. They are also used for chewing and grinding food.

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Question 6:

Sketch and label a diagram of the digestive system and describe it in your own words.

ANSWER:

Major constituent organs of the human digestive system are: buccal cavity, oesophagus, stomach, small intestine, large intestine, rectum and anus.

Buccal cavity − It includes the teeth, saliva and tongue. The teeth break down the food. Digestion of food begins in the mouth. The tongue helps in the chewing and swallowing of food.

Oesophagus − The food passes from the mouth, down the oesophagus, into the stomach, as a result of the movement of the walls of the oesophagus.

Stomach − It mixes the food received from the oesophagus with digestive juices.

Small intestine − The food from the stomach moves into the small intestine, which receives intestinal juices from two glands − liver and pancreas. These juices help in the further digestion of food.

Large intestine − Water is absorbed in the large intestine.

Rectum and anus − Undigested food particles are thrown out with the help of the rectum and anus.

Acids, Bases and salts

Q 1. Identify the odd one out and justify.

(a)  Chloride, nitrate, hydride, ammonium

(b) Hydrogen chloride, sodium hydroxide, calcium oxide, ammonia

(c) Acetic acid, carbonic acid, hydrochloric acid, nitric acid

(d) Ammonium chloride, sodium chloride, potassium nitrate, sodium sulphate

(e)  Sodium nitrate, sodium carbonate, sodium sulphate, sodium chloride

(f)  Calcium oxide, magnesium oxide, zinc oxide, sodium oxide.

(g) Crystalline blue vitriol, crystalline common salt, crystalline ferrous sulphate, crystalline sodium carbonate.

(h) Sodium chloride, potassium hydroxide, acetic acid, sodium acetate.

ANSWER:

ans
a.Ammonium = NH₄⁺
Nitrate = NO₃^-
Hydride = H^-
Chloride = Cl^-
Ammonium is odd because Ammonium is cation and rest are anions.

b.Hydrogen chloride is odd because Hydrogen chloride is acid and rest are base.

c.Acetic acid = CH₃COOH
   Carbonic acid = H₂CO₃
   Hydrochloric acid = HCl
   Nitric acid = - HNO₃
   HCl is the only Diatomic Hetro-Nuclear compound and remaining are Poly Atomic compound.

d.Ammonium chloride is odd  because it is acidic salt and rest all are neutral salts.

e.Sodium carbonate is odd because the solutions of sodium nitrate, sodium sulphate and sodium chloride are neutral. But the solution of sodium carbonate is BASIC.

f.Calcium oxide = CaO
   Magnesium oxide = MgO
   Zinc oxide = ZnO
   sodium oxide = Na₂O
   ZnO is odd because it is amphoteric in nature and other ions are basic in nature

g.Common salt is odd because on heating, there is no change in color of compound. But in rest of the compounds, there is change is colour.

h. Potassium hydroxide is odd because in a reaction, when Sodium chloride reacts with acetic acid, then Sodium acetate is formed. There is no role of Potassium hydroxide in the reaction given below.
NaCl +CH3COOH→CH3COONa +HCl$\mathrm{NaCl} +{\mathrm{CH}}_3\mathrm{COOH}\to {\mathrm{CH}}_3\mathrm{COONa} +\mathrm{HCl}$

Page No 73:

Question 2:

Write down the changes that will be seen in each instance and explain the reason behind it.

(a)  50ml water is added to 50ml solution of copper sulphate.

(b) Two drops of the indicator phenlphthalein were added to 10ml solution of sodium hydroxide.

(c)  Two or three filings of copper were added to 10ml dilute nitric acid and stirred.

(d) A litmus paper was dropped into 2ml dilute HCl. Then 2ml concentrated NaOH was added to it and stirred.

(e)  Magnesium oxide was added to dilute HCl and magnesium oxide was a added to dilute NaOH.

(f)  Zinc oxide was added to dilute HCl and zinc oxide was added to dilute NaOH.

(g)  Dilute HCl was added to limestone.

(h)  Pieces of blue vitriol were heated in a test tube. On cooling, water was added to it.

(i) Dilute H 2 SO 4 was taken in an electrolytic cell and electric current was passed through it.

ANSWER:

ans
a. When 5o mL water is added to 50 mL solution of copper sulphate, then reversible reaction occurs and the colour change from pale blue to white and then change back to blue when water is added again.

CuSO4 +H2O ↔ CuSO4.5H2O ( BLUE VITRIOL).$���{�}_4 +{�}_2� \leftrightarrow ���{�}_4.5{�}_2� ( ���� �������).$

b. Phenolphthalein is an indicator used for determining the quantity of base. When two drops of Phenolphthalein indicator are added to 10 mL solution of Sodium hydroxide, then the solution turns pink in colour because the acidic part of phenophthalein reacts with the base, it forms sodium salt of phenolphthalein which has pink color.
For example : In acid base titration phenolphthalein is used to detect end point of base.

c. Copper is an unreactive metal and doesn’t react in normal circumstances with dilute acids.

There are actually two equations for the reaction of copper with nitric acid take place. It depends on whether the nitric acid is concentrated or not. If it is concentrated, then the ratio is 1:4  for copper to nitric acid. If it is dilute then the ratio is 3:8.

 

Cu + 4HNO3 (dil.)→Cu(NO3)2 + 2NO2 + 2H2O  3Cu + 8HNO3 (conc.)→ 3Cu(NO3)2 + 2NO + 4H2O$$\begin{gathered} �� + 4��{�}_3 (���.)\to ��(�{�}_3{)}_2 + 2�{�}_{2 }+ 2{�}_2� \\ 3�� + 8��{�}_{3 }(����.)\to 3��(�{�}_3{)}_2 + 2�� + 4{�}_2� \end{gathered}$$
Concentrated Nitric acid  is act as strong oxidising agent so it makes sense that a higher oxidation state of nitrogen (IV) oxide is formed .

d. When litmus paper is dipped into 2 mL of dilute HCl solution , then blue litmus paper is turned into red colour and there is no effect on red litmus paper. Again, if the same litmus paper is dipped into 2 mL of concentrated NaOH solution, then red litmus paper turns into blue colour but there is no effect on blue litmus paper.This is due to the respective properties of blue and red litmus paper with acid and base.
 

e. Magnesium oxide is a base. when base reacts with an acid, it forms salt and water.This reaction is known as neutralisation reaction.

MgO(s) + 2HCl(l) = MgCl2 (aq) + H2O(l)$���\left(�\right) + 2���\left(�\right) = ���{�}_{2 }\left(��\right) + {�}_2�\left(�\right)$

MgO doesnot react with NaOH.As NaOH is a base and bases react only with oxides of non-metal to form salt and water because oxides of non-metals are said to be acidic in nature so neutralization reaction take place. But MgO is a oxide of metal so, reaction is not possible.

f. Zinc oxide is added to dilute HCl, then neutralization reaction takes place to form salt and water.
The reaction is as follows:

ZnO(aq)+2HCl(aq)→ZnCl2(aq)+H2O(l)$���\left(��\right)+2���\left(��\right)\to ���{�}_2\left(��\right)+{�}_2�\left(�\right)$

Zinc oxide reacts  with sodium hydroxide to produce zincate sodium and water. This reaction takes place at a temperature of 500-600°C.it is exothermic reaction.
ZnO + 2NaOH→Na2ZnO2 + H2O$\mathrm{ZnO} + 2\mathrm{NaOH}\to {\mathrm{Na}}_2{\mathrm{ZnO}}_2 + {\mathrm{H}}_2\mathrm{O}$

g. Limestone is calcium carbonate. When limestone is added to a 10% solution of dilute HCl, then brisk effervescence of CO₂ is released due to the reaction of acid with carbonate of metals.

2HCl + CaCO3 → CaCl2 + CO2 +H20$2��� + ���{�}_3 \to ���{�}_{2 }+ �{�}_2 +{�}_{2}0$

h. When pieces of blue vitriol are heated in a test tube, then crystal structure of blue vitriol broke down to forn a colourless powder and water come out. This water is called water of crystallization. when water is added to the same test tube, then white powder turned into blue colour again.This is due to reversible reaction take place from anhydrous salt to hydrous salt and vice-versa.
CUSO4.5H2O↔CUSO4 +5H2O$���{�}_4.5{�}_2�\leftrightarrow ���{�}_4 +5{�}_2�$
 

i. When a dilute solution of sulfuric acid is electrolysed, gases are produced at both the anode and the cathode electrode.

t

 

The gas produced at the cathode burns with a 'pop' sound, when a sample is lit with a lighted splint. This shows that the gas is hydrogen.

The gas produced at the anode relights a glowing splint dipped into a sample of the gas. This shows that the gas is oxygen.

The gases are produced when ions move towards the electrodes.

At the cathode:

2H⁺ +2e^- → H₂

At the anode:

4OH^- - 4e^- → 2H₂O + O₂

 

Page No 73:

Question 3:

Classify the following oxides into three types and name the types.

CaO, MgO, CO₂ , SO₃ , Na₂O, ZnO, Al₂O₃ , Fe₂O₃

ANSWER:

Oxides are of three types :

1) Acidic Oxides: CO₂ (Carbon dioxide), SO₃ (Sulfur trioxide)

2) Basic Oxides: CaO (Calcium oxide), MgO (Magnesium oxide), Na₂O (Sodium oxide)

3) Amphoteric Oxides: ZnO (Zinc oxide), Al₂O₃ (Aluminium oxide), Fe₂O₃ (Ferric oxide)

Page No 73:

Question 4:

Explain by drawing a figure of the electronic configuration.

a. Formation of sodium chloride from sodium and chlorine.

b.  Formation of a magnesium chloride from magnesium and chlorine.

ANSWER:

a. Atomic number of Sodium(Na) atom is 11.
Electronic configuration is :
Na = 2, 8, 1
So it contains 1 valence electron. In order to achieve the nearest noble gas configuration, it loses one electron to form Sodium ion.
Na⁺ = 2,8

Atomic number of Chlorine(Cl) atom is 17.
Electronic configuration is :
Cl = 2, 8, 7
So it contains 7 valence electron. In order to achieve the nearest noble gas configuration, it gains one electron to form Chloride ion.
Cl^- = 2,8
An Ionic bond is formed between sodium ion and chloride ion by complete transfer of electron from sodium to chlorine.



b. Atomic number of Magnesium(12) atom is 12.
Electronic configuration is :
Mg = 2, 8, 2
So it contains 2 valence electron. In order to achieve the nearest noble gas configuration, it loses two electrons to form Magnesium ion.
Mg²⁺ = 2,8

Atomic number of Chlorine(Cl) atom is 17.
Electronic configuration is :
Cl = 2, 8, 7
So it contains 7 valence electron. In order to achieve the nearest noble gas configuration, it gains one electron to form Chloride ion.
Cl^- = 2,8
An Ionic bond is formed between Magnesium ion and two Chloride ion by complete transfer of one electron to each Chlorine ion.

Page No 74:

Question 5:

Show the dissociation of the following compounds on dissolving in water, with the help of chemical equation and write whether the proportion of dissociation is small or large .

Hydrochloric acid, Sodium chloride, Potassium hydroxide, Ammonia, Acetic acid, Magnesium chloride, Copper sulphate

ANSWER:

a.HCl(aq) + H2O(l)→H3O⁺(aq)+Cl^-(aq)
Explanation:
Hydrochloric acid(HCl) is a strong acid, so HCl is ionize completely in aqueous solution.In other words, every molecule of hydrochloric acid that is added to water will donate its proton H⁺ to water molecule to form a hydronium cation, and H₃O⁺and chloride ions Cl^-  is formed.

b.Reaction:
NaCl(s) + H₂O(aq) -> Na⁺(aqueous) + Cl^-(aqueous) + H₂O(l)
Explanation:
When sodium chloride reacts with water the Na⁺ part of NaCl is attracted to the oxygen side of the water molecules, while the Cl^- side is attracted toward the hydrogen's side of the water molecule.

 

 

    

This causes the sodium chloride(salt) to split in water and the NaCl ionises into Na⁺ and Cl^- ions completely.
 

c)KOH(s) + H₂O(l)<--> K⁺(aq) + OH^-(aq) + H₂O(l)
Explanation:
KOH is base, so mixing it in water makes a basic solution that is in equilibrium. the KOH is just dissolving in the water.

 

d)NH₃(base) + H₂O(acid)<--> NH₄⁺(conjugate acid) + OH^-(conjugate base)
Explanation:
when ammonia dissolves in water. In an aqueous solution, ammonia acts as a base, acquiring hydrogen ions from H₂O to yield ammonium cation and hydroxide ions.

e)CH₃COOH(l) + H₂O(l) -> CH₃COO^-+ H₃O⁺
Explanation:
When acetic acid is added to water, due to electronegativity differences of oxygen and hydrogen in OH group of acetic acid and there is a dipole interaction with water molecule. Hence, the acetic acid is ionise into acetate ion and H⁺ ion combines with water to form hydronium ion.  —

 

f)MgCl₂(s) + H₂O(l) -> Mg²⁺(aqueous) + Cl^-(aqueous) + H₂O(l)
Explanation:
On addition to water the Mg²⁺ part of MgCl₂ is attracted to the oxygen side of the water molecules, while the Cl- side is attracted to the hydrogen's side of the water molecule . This causes magnesium chloride(salt) to split in water and the MgCl₂  is ionise into Mg²⁺ and Cl^- ions completely.

 

g)CuSO₄ (s) + H₂O (l) --> Cu⁺² (aq) + SO₄^-2 (aq) +  H₂O(l)
Explanation:
when a compound dissolves in water, it dissociates to form ions.The reaction between anhydrous copper(II) sulphate(white) and water  turns blue in the presence of water.

Page No 74:

Question 6:

Write down the concentration of each of the following solutions in g/L and mol/L.

a.  7.3g HCl in 100ml solution

b.   2g NaOH in 50ml solution

c.   3g CH₃COOH in 100ml solution

d.   4.9g H₂SO₄ in 200ml solution

ANSWER:

a)7.3 g HCl in 100 mL solution:


Concentration of HCl in g L−1 =Mass of solute in gramVolume of HCl in litre$\mathrm{Concentration} \mathrm{of} \mathrm{HCl} \mathrm{in} \mathrm{g} {\mathrm{L}}^{-1 }=\frac{���� �� ������ \mathrm{in} \mathrm{gram}}{\mathrm{Volume} \mathrm{of} \mathrm{HCl} \mathrm{in} �����}$
                                     
                                      =7.3 × 1000100=73$=\frac{7.3 \times 1000}{100}=73$ g L^-1

In terms of gram per litre:
7.3 g of HCl in 100 mL has concentration = 73 g L^{-1
 
Molecular mass of HCl = 1+35.5=36.5$1+35.5=36.5$}

Molarity =Mass of solute in molesVolume of HCl in L$\mathrm{Molarity} =\frac{\mathrm{Mass} \mathrm{of} \mathrm{solute} \mathrm{in} �����}{\mathrm{Volume} \mathrm{of} \mathrm{HCl} \mathrm{in} \mathrm{L}}$

            =7.3 × 100036.5 ×100=2$=\frac{7.3 \times 1000}{36.5 \times 100}=2$ mol L^-1

In terms of moles per litre:
7.3 g of HCl in 100 mL has concentration = 2 mol L^-1

 
b)2g NaOH in 50 mL solution


Concentration of NaOH in g L−1 =Mass of NaOH in gVolume of NaOH in L$������������� �� ���� �� � {�}^{-1 }=\frac{���� �� ���� �� �}{������ �� ���� �� �}$
                                     
                                      =2 × 100050= 40$=\frac{2 \times 1000}{50}= 40$ g L^-1
In terms of gram per litre:
2 g of NaOH in 50 mL has concentration = 40 g L^{-1
 
Molecular mass of NaOH = 23 +16 + 1 = 40$23 +16 + 1 = 40$}

Molarity =Mass of solute in molesVolume of NaOH in L$\mathrm{Molarity} =\frac{\mathrm{Mass} \mathrm{of} \mathrm{solute} \mathrm{in} �����}{\mathrm{Volume} \mathrm{of} ���� \mathrm{in} \mathrm{L}}$

            =2 × 100040 ×50=1$=\frac{2 \times 1000}{40 \times 50}=1$ mol L^-1

In terms of moles per litre:
2 g of NaOH in 50 mL has concentration = 1 mol L^-1


c)3 g CH₃COOH in 50 mL solution


Concentration of CH3COOH in g L−1 =Mass ofCH3COOH in gVolume of CH3COOH in L$������������� �� �{�}_3���� �� � {�}^{-1 }=\frac{���� ���{�}_3���� �� �}{������ �� �{�}_3���� �� �}$
                                     
                                      =3 × 1000100= 30$=\frac{3 \times 1000}{100}= 30$ g L^-1
In terms of gram per litre:
3 g of CH₃COOH in 100 mL has concentration = 30 g L^{-1
 
Molecular mass of}  CH₃COOH ^{= 2 × 12 + 2 × 16 + 4 × 1 = 60$2 \times 12 + 2 \times 16 + 4 \times 1 = 60$}

Molarity =Mass of solute in molesVolume of solution in L$�������� =\frac{���� �� ������ �� �����}{������ �� �������� �� �}$

            =3 × 100060 ×100=0.5$=\frac{3 \times 1000}{60 \times 100}=0.5$ mol L^-1

In terms of moles per litre:
3 g of  CH₃COOH in 100 mL has concentration = 0.5 mol L^-1

d)4.9 g H₂SO₄  in 200 mL solution


Concentration of H2SO4 in g L−1 =Mass of H2SO4 in gVolume of H2SO4 in L$������������� �� {�}_2�{�}_{4 }�� � {�}^{-1 }=\frac{���� �� {�}_2�{�}_4 �� �}{������ �� {�}_2�{�}_{4 }�� �}$
                                     
                                                =4.9 × 1000200= 24.5$=\frac{4.9 \times 1000}{200}= 24.5$ g L^-1
In terms of gram per litre:
4.9 g of  H₂SO₄ in 200 mL has concentration = 24.5 g L^{-1
 
Molecular mass of}   H₂SO₄ ^{= 2 × 12 + 2 × 16 + 4 × 1 = 60$2 \times 12 + 2 \times 16 + 4 \times 1 = 60$}

Molarity =Mass of solute in molesVolume of solution in L$�������� =\frac{���� �� ������ �� �����}{������ �� �������� �� �}$

            =4.9× 100098 ×200=1$=\frac{4.9\times 1000}{98 \times 200}=1$ mol L^-1

In terms of moles per litre:
4.9 g of   H₂SO₄ in 200 mL has concentration = 1 mol L^-1

Page No 74:

Question 7:

Obtain a sample of rainwater. Add to it a few drops of universal indicator. Measure its pH. Describe the nature of the sample of rainwater and explain the effect if it has on the living world.

ANSWER:

Ans7.This is an activity based question in which you are supposed to collect rainwater from different places and compare there results on the basis of following parameters :
a) pH of water
b)Action of water on blue litmus paper
c)Action of water on red litmus paper
d)Effect of indicator like phenolphthalein and methyl orange
Conclusion :
If we take samples of rain water from different places, we observe the following results :

• pH of water is in between 1-6
• Blue litmus paper turns red
• No change in colour of red litmus paper
• No change in colour of rain water on adding phenolphthalein
• rain water turns red in colour on adding methyl orange

The above observations show that rainwater is acidic in nature. For further assurance, we cancompare blue litmus paper dipped in different samples of rainwater with pH scale.
If rain water is acidic, then its pH must be in the range of 0-6.
The strength of ac acid depends on its pH value i.e. lower the value of pH, higher will be the strength of an acid and vice-versa.

Page No 74:

Question 8:

Answer the following questions.

a.   Classify the acids according to  their basicity and give one examplen of each type.

b.   What is meant by neutralization? Give two examples from everyday life of the neutralization reaction.

c.  Explain what is meant by electrolysis of water. Write the electrode reactions and explain them.

ANSWER:

Ans 8.

a. The number of ionizable hydrogen (H+) ions present in one molecule af an acid is called its basicity.

 For example :
HCl   ---------> H⁺ + Cl^-
Basicity of HCl is 1.

H₂SO₄ ------> 2H⁺ + SO₄^2-
Basicity of  H₂SO₄ is 2.

Based on Basicity acids were classified into different types :
1. Mono-basic acids
2. Di-basic acids
3. Tri-basic acids

1. Mono-basic acids :

Acids, which on ionisation produce one hydronium ion on reaction with water.
Acids, which on ionisation produce one hydrogen ion.
For example : HCl, HNO₃ etc.

2. Di-basic acids :

Acids, which on ionisation produce two hydronium ion on reaction with water
Acids, which on ionisation produce two hydrogen ion

For example : H₂SO_4, H₂CO₃ etc.

3. Tri-basic acids :

Acids, which on ionisation produce three hydronium ion on reaction with water
Acids, which on ionisation produce three hydrogen ion

For example : H₃PO₄, H₃PO₃ etc.
 
b. Neutralization reaction :

A neutralization reaction is a reaction in which an acid and a base reacts to form water and a salt. It involves the combination of H⁺ ions and OH^- ions to generate water.
The neutralization of a strong acid and strong base has a pH equal to 7.
The neutralization of a strong acid and weak base will have a pH of less than 7.
The neutralization of a strong base neutralizes a weak acid will be greater than 7.

When a solution is neutralized, it means that salts are formed from equal weights of acid and base.

Neutralization reaction has application in daily life:

1)Self defence by animals and plants through chemical warfare :

Bee stings are acidic in nature, household remedy for a bee sting is baking soda or sodium bicarbonate, which is a basic substance.
A wasp stings are mildly basic, household remedy for this will be vinegar, also known as acetic acid.
These simple treatments ease these painful stings by a process called neutralization.

2)pH in our digestive system :
An acidic stomach due to eating too much spicy food, can be relieved by taking an antacid. The antacid is alkaline/basic in nature and helps to neutralize the stomach's acidity or you may take magnesium hydroxide(Milk of magnesia) and sodium hydrogen carbonate(Baking soda).

3) pH change as the cause of tooth decay :
When we eat food containing sugar, then bacteria present in our mouth break down the sugar to form acids(such as lactic acid). Thus acid is formed in the mouth after digestion. This will lead to the cause of tooth decay. The best way to prevent tooth decay is to clean the mouth after eation food with toothpaste, which is basic in nature. This will result in neutralization of acid by base.
 
4)soil pH and plant growth :
Most of the plants grow best when the pH of the soil is close to 7 that's neural. If the soil is too acidic or too basic(alkaline), the plants grow badly.
The acidic soil is neautralize by treatment with materials like quicklime(calcium oxide) or slaked lime(calcium hydroxide) or chalk(calcium carbonate).
If the soil is too basic, then alkalinity can be reduced by adding decaying organic matter(manure or composite)which contains acidic materials.

 

c.Electrolysis of water :

Electrolysis of water is the decompositon into oxygen and hydrogen gas due to an electric current passed through the water.

The following equation represents the electrolysis of water :H2O(l)

In pure water, at the negatively charged cathode, a reduction reaction takes place, with electrons (e⁻) from the cathode being given to hydrogen cations to form hydrogen gas.

Reduction at cathode: 2 H⁺ + 2e⁻ → H₂

On positively charged anode, an oxidation reaction occurs, generating oxygen gas by giving electrons to the anode :

Oxidation at anode: 2 H₂O → O₂(g) + 4 H⁺(aq) + 4e⁻

The same half reactions can also be balanced with base as listed below. To add half reactions they must be balanced with either acid or base.

Cathode (reduction):	2 H2O(l) + 2e−	→	H2(g) + 2 OH−(aq)
Anode (oxidation):	4 OH−(aq)	→	O2(g) + 2 H2O(l) + 4 e−

Combining either half reaction pair yields the same overall decomposition of water into oxygen and hydrogen:

Overall reaction: 2 H₂O(l) → 2 H₂(g) + O₂(g)

The number of hydrogen molecules produced is thus twice the number of oxygen molecules.  The produced hydrogen gas has therefore twice the volume of the produced oxygen gas. The number of electrons pushed through the water is twice the number of generated hydrogen molecules and four times the number of generated oxygen molecules.

2H2O(l)⟶2H2(g)+O2(g)

 

 

 

 

Page No 74:

Question 9:

Give reason for the following.

a. Hydronium ions are always in the form H₃ O⁺

b. Buttermilk spoils if kept in a copper or brass container.

ANSWER:

a)When an acids dissolve in water. The H⁺ ion from acid always goes to the nearest water molecule to form hydronium ion.
HCl(aq)+H₂O(aq)→H3O⁺(aq)+Cl-(aq)
For example : When Hydrochloric acid(HCl) is a strong acid. When it is dissolved in water, HCl is ionized completely in aqueous solution.  Hydrochloric acid will donates its proton H⁺ to water molecule to form a hydronium cation H₃O⁺and chloride anions Cl^- .

b)Buttermilk spoils if kept in a copper or brass container because buttermilk is actually lactic acid. Lactic acid reacts with the container material and produces poisonous complex. It is actually the reaction between acid and metal . This reaction is called as electro chemical reaction.

Page No 74:

Question 10:

Write the chemical equations for the following activities.

(a) NaOH solution was added to HCl solution.

(b) Zinc dust was added to dilute H₂ SO₄ .

(c) Dilute nitric acid was added to calcium oxide.

(e) Carbon dioxide gas was passed through KOH solution.

(f) Dilute HCl was poured on baking soda.

ANSWER:

a. HCl(l) + NaOH(l) → NaCl(s) + H2O(l) + Energy b. Zn(s)+ H2SO4(l)→ ZnSO4(s) +H2 (g)c. CaO(s) + 2HNO3(l)→ Ca(NO3)2 (s)+ H2O(l) d. KOH(l) + CO2(g)→ KHCO3 e. NaHCO3(s)+ 2HCl(l)→ NaCl(s) + H2O (l)+ CO2$$\begin{gathered} �. \mathrm{HCl}\left(\mathrm{l}\right) + \mathrm{NaOH}\left(\mathrm{l}\right) \to \mathrm{NaCl}\left(\mathrm{s}\right) + {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) + \mathrm{Energy} \\ \mathrm{b}. \mathrm{Zn}\left(\mathrm{s}\right)+ {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{s}\right) +{\mathrm{H}}_{2 }\left(\mathrm{g}\right) \\ \mathrm{c}. \mathrm{CaO}\left(\mathrm{s}\right) + 2{\mathrm{HNO}}_3\left(\mathrm{l}\right)\to \mathrm{Ca}({\mathrm{NO}}_3{)}_2 (\mathrm{s})+ {\mathrm{H}}_2\mathrm{O}(\mathrm{l}) \\ \mathrm{d}. \mathrm{KOH}(\mathrm{l}) + {\mathrm{CO}}_2(\mathrm{g})\to {\mathrm{KHCO}}_{3 } \\ \mathrm{e}. {\mathrm{NaHCO}}_3(\mathrm{s})+ 2\mathrm{HCl}(\mathrm{l})\to \mathrm{NaCl}(\mathrm{s}) + {\mathrm{H}}_2\mathrm{O} (\mathrm{l})+ {\mathrm{CO}}_2 \end{gathered}$$

Page No 74:

Question 11:

State the differences.

a.  Acids and bases

b.   Cation and anion

c.  Negative electrode and positive electrode.

ANSWER:

Ans. a.

Parameter	Acid	Base
Arrhenius Definition	substance which when dissolved in water gives  hydrogen ion	substance which when dissolved in water can accept hydrogen ions
Bronstead Lowry Definition	substance which donates a proton	substance which accepts a proton
Strength	depends on the concentration of the hydronium ions	depends on the concentration of the hydroxide ions
Characteristics (Physical)	depends upon the temperature as it can be solid, liquid or in the form of gas have a sour taste	can be solid in nature except ammonia which is gaseous have a bitter taste can be slippery in touch
Dissociation	releases hydrogen ions (H+) when mixed with water	releases hydroxide ions(OH-) when mixed with water
pH value	less than 7.0	greater than 7.0
Litmus paper	blue litmus paper turns red	red litmus paper turns blue
Chemical Formula	has a chemical formula with H at the beginning of it. For example, HCl (Hydrochloric Acid). There is one exception to this rule, CH3COOH = Acetic Acid (vinegar)	has a chemical formula with OH at the end of it. For example, NaOH (Sodium Hydroxide)

b.

Cations	Anions
positively charged particles	negatively charged particles
formed by loss of electrons from metals	formed by gain of electrons from non-metals
during electrolysis, it moves towards cathode	during electrolysis, it moves towards anode
size of cation is smaller than its parent atom	size of anion is same or larger than its parent atom
for examples : Na+, Mg2+,Ca2+ etc.	for examples :Cl-, Br-,S2- etc.

c.

Negative Electrode	Positive Electrode
refers to a piece of electrochemical cell that is the negative pole	refers to a piece of electrochemical cell that is the positive pole
connects to negative terminal of a battery by means of wire	connects to positive terminal of a battery by means of wire
also called as cathode	also called as anode
positive charged cations moves toward it	negative charged anions moves toward it
accepts electrons to deposite	donates electron

 

Page No 74:

Question 12:

Classify aqueous solutions of the following substances according to their pH into three groups : 7, more than 7, less than 7.

Common salt, sodium acetate, hydrochloric acid, carbon dioxide, potassium bromide, calcium hydoxide, ammonium chloride, vinegar, sodium carbonate, ammonia, sulphur dioxide.

ANSWER:

Ans7.
 

SUBSTANCES	pH Value
Solution of Common salt	equal to 7
Solution of Sodium acetate	greater than 7
Solution of Hydrochloric acid	less than 7
Solution of Carbon dioxide	less than 7
Solution of Potassium bromide	equal to 7
Solution of Calcium hydroxide	greater than 7
Solution of Ammonium chloride	less than 7
Solution of Vinegar	less than 7
Solution of Sodium carbonate	greater than 7
Solution of Ammonia	greater than 7
Solution of Sulphur dioxide	less than 7