Class 10th Ch-2 Solved Extra Question Answers

Class 10th Science Ch-2 Ncert Exemplar Question Answers
Class 10th Science Ch-2 Ncert Exemplar Question Answers

Class 10th Ch-2 Solved Extra Question Answers:- Here In this Blog, I have Explained about the Important Question that is Asked in your Board Exams all of these Questions are very Important form your Examp Perspective.

After attending, learning and Compleating these questions your almost Queries syllabus and the doubts related to the Concepts of this chapter will be cleared.

So, Enjoy this Content until the end. And as usual, Don’t forget to share with your all other friends.

Very short Answers Questions/Answer [1-Marks]

Q1. Two solutions A and B have pH values of 5 and 8 respectively. Which solution will be basic in nature?

Ans:- Solution ‘B’.

Q2. If a few drops of concentrated acid accidentally spills over the hand of a student, What should be done?

Ans:- In this case, the hand of the student should be immediately washed with plenty of water and Paste of Sodium hydrogen Carbonate (NaHCO3) should be applied.

Q3. If someone is suffering from the problem of acidity after overeating: Which of the following would you suggest as a Redmy?

Lemon Juice, baking Soda solution or Vinegar.

Ans:- Baking soda (Na2CO3) solution Because it is basic in nature and hence it neutralizes the excess acid present in the stomach and overcomes the Acidity.

Q4. Arrange the following in increasing order of Acidic strength.

Acetic Acid, water, and hydrochloric acid.

Ans:- Water (pH=7)<Acetic acid (5.06) < Hydrochloric acid (3.01)

Q5. Why does tooth decay start when the pH of the mouth is lower than 5.5?

Ans:- Tooth decay starts when the pH of mouth goes lower than 5.5 because below this pH value the mouth becomes more Acidic and hence it starts corroding top our teeth enamel at a faster rate.

Q6. Explain why an aqueous solution of Ammonium Chloride (NH4Cl) is acidic in nature?

Ans:- Ammonium Chloride formula is Nh4Cl means this compound is formed by the reaction of strong Acid HCl and a weak base Ammonium hydroxide(NH4OH).

The Salt of a Strong acid and a weak base is always Acidic in Nature.

Q7. What are the products formed when acids react with a Base?

Ans:- when acid and Base reacts with each other then salt and H2O formed. Example:- HCl + NaOH —-> NaCl + H2O

Q8. What is the commercial name of calcium Sulphate Hemihydrate?

Ans:_ Calcium Sulpahete hemihydrate is also known as Plaster of Paris (POP)

Q8. Name the substance obtained by the action of chlorine on dry slaked lime?

Ans:- The substance which is obtained by the action of chlorine on dry slaked lime is Bleaching powder.

Q9. Plaster of Paris should be stored in a moisture-proof container explain why?

Ans:- plaster of Paris is Stored in Moisture-proof Container because It reacts with the moisture present in the Atmosphere to form a hard white color of Compound that is Gypsum.

Q10. Why is the electrolysis of a concentrated solution of sodium chloride known as a Chlor-Alkali process?

Ans:- The electrolysis of the concentrated solution of sodium chloride known as the Cholor-Alkali process Because at the end of the Reaction the products formed are Chlorine and Sodium hydroxide(alkali).

Short Answers questions Part-1 [2-Marks]

Q1. What is an olfactory Indicator? Name two such Indicators.

Ans:- These are the indicators that change their Smell in the presence of Acid or a Base. Example:- Onion and Vanilla Extract.

Q2. name the acids present in the following:

(i). Tomato (ii) Vinegar (iii). tamarind

Ans:- (i). Tomato —-> Citric acid

(ii). Vinegar —–> Acetic Acid.

(iii). Tamarind ——-> Tartaric Acid.

Q3. The pH of soil A is 7.5 while that of soil B is 4.5. Which of the two soils should be treated with powdered chalk to adjust its ph and why?

Ans:- Chalk powder is made up of Calcium carbonate, which is Basic in nature. So, In soil B (pH is 4.5), when we apply Chalk Powder the pH of the soil will Neutralise.

Q4. What is Baking powder? How does it make the cake soft and Spongy?

Ans:- Baking powder is the Mixture of Baking Soda and an Eaidable Acid that is Tartaric acid. When Baking powder is heated in the presence of oxygen then it Releases CO3 that causes the bread and cake to rise to make it soft and Spongy.

NaHCO3 + H+ ——> CO2 + H2O + Sodium salt of Taartaric acid.

Q3. (i). Name the products formed when sodium hydrogen carbonate is heated.

(ii). Write the chemical equation involved in it.

Ans:- When Sodium hydrogen carbonate is heated then it forms Na2CO3 Sodium Carbonate + CO2 (Carbon dioxide) and H2O.

(ii). The Chemical Equation of this reaction will be:-

NaHCO3 (Sodium Hydrogen Carbonated) (Heat) ——–> Na2CO3 (Sodium Carbonate) + H2O + CO2

Q4. What will happen when Nitric Acid will be added to an eggshell?

Ans:- Eggshell is made up of Calcium Carbonate (CaCO3). And when Calcium Carbonate reacts with the Nitric Acid then calcium nitrate will form and also CO2 will be Produced

CaCO3 + HNO3 ——> Ca(NO3)2 + H2O + CO2

Short answer/Question type 2 [3-Marks]

Q1. Which acid is produced in our stomach? what happens if there is an Excess of acid in the stomach? How can it effect be cured?

Ans:- HCl (Hydrochloric acid) is produced in our Stomach to digest the food. If there is an Excess of an acid produced in the Stomach then it causes indigestion which causes Pain and Irritation.

This Effects can be cured by using antacids. Basically, Antacids are the group of mild bases that reacts with the acid present in the stomach and then neutralize the Acidic effect and gives relief from Pain and Irritation.

Q2. A salt X, when dissolved in distilled water, gives a clear solution that turns red litmus blue. Explain this phenomenon.

Ans:- Basic solution turns red litmus paper blue. The salt of a weak acid and a strongly basic solution. So, the given salt X is the salt of a weak acid and a strong base.

Example:- When sodium Carbonate is dissolved in water, it gets hydrolyzed to some extent from sodium hydroxide and carbonic acid.

Na2CO3 + 2H2O ——> 2NaOH + H2CO3 (aq)

Q3. With the help of a chemical equation, Explain how a soda-acid Fire Extinguisher helps in putting out the fire.

Ans:- Soda-Acid Fire Extinguisher, there are two different containers that contain Sulphuric acid and Sodium bicarbonate. And when the reaction between the NaHCO3 and H2SO4 takes place then a lot amount of CO2 gas is produced which helps in Extinguish the Fire.

2NaHCO3 + H2SO4 —–> Na2SO4 + 2H2O + 2CO2

Q4. How would you distinguish between the baking powder and washing soda by heating?

Ans:- The Chemical Formula of baking powder is NaHCO3 (Sodium Hydrogen Carbonate), And the formula of Washing soda is Na2CO3.10H2O.

When sodium hydrogen Carbonated is heated then it produces Sodium carbonate + CO2 + H2O.

Whereas when Washing soda is heated it produces Na2CO3 + 10H2O

NaHCO3 (Heat) —-> Na2CO3 + H2O + CO2

Na2CO3.10H2O ——> Na2CO3 + 10H2O, carbon-di-oxide is not produced in this case.

Class 10th Ch-2 Solved Extra Question Answers Q5.

Ans:- (i). Calcium chloride and chlorine gas are formed.

CaOCl2 + HCl —-> CaCl2 + H2O Cl2

(ii). Hydrogen gas is evolved.

Zn + HCl —-> ZnCl2 + H2

(iii). Sodium chloride and carbon dioxide gas are formed.

NaHCO3 + HCl ——–> NaCl + H2O + CO2

Class 10th Ch-2 Solved Extra Question Answers Q6.

Ans:- The Compound prepared from gypsum on heating in at 100`C, is known as Plaster of Paris. Its chemical formula is CaSO4.1/2H2O. Hence, Its calcium name is calcium hemihydrate. The Chemical equation for its preparation is as follow:

CaSO4.2H2O ——–> CaSO4.1/2H2O + 1*1/2H2O

Plaster of Paris is used in hospitals mainly as plaster for supporting fractured bones in the right position. In Chemistry, is used for making casts.

Q7. What do you mean by the water of Crystallisation? Explain that the crystalline salts contain water of Crystallisation.

Ans:- Water of Crystallisation:- The Fixed no. of water Molecules that present in the one formula unit of a Salt. Example:- One formula unit of Copper Sulphate (CuSO4.5H2O) contains 5 water molecules. These 5 water molecules are known as Water of Crystallisation. These are also called Hydrated Sats and when on strong Heating it becomes unhydrated and loses their water of Crystylisation.

CuSO4.5H2O (Heat) —–> CuSO4 + 5H2O

Class 10th Ch-2 Solved Extra Question Answers Q8.

Ans:- (i). When we do overeat than the excess amount of Acid releases in our body that cause the sensation of burning after overeating.

(ii). This is because Washing Soda contains 10 molecules of water and when we exposed it in the air then it looses the 10 molecules of water and then changes to white color Powder.

(iii). Because, NaCl (Sodium Chloride) is made up of Strong acid and a Strong Base, that’s why the salt is very neutral in nature. But Sodium Carbonate (Na2CO3) is made up of a strong base (NaOH) and a Weak Acid (Carbonic acid (H2CO3)).

Long Questions Answer [5-Marks]:-

Class 10th Ch-2 Solved Extra Question Answers Q1.

Ans:- (i). The reaction takes place with greater speed and also a large amount of Hydrogen gas will release.

(ii). Almost the same amount of gas will release because both of these acids are very strong in nature.

(iii). Similiar, the reaction will take place and hydrogen gas ill release. Zn + 2NaOH —–> Na2ZnO2 (Sodium Zincate) + H2

(2). Yes, All metal Carbonates and Metal Hydrogen Carbonates reacts with te Metal hydrogen carbonate.

Metal Carbonate + Acid —-> Salt + Carbon Dioxide + Water.

Metal hydrogen Carbonate + Acid ——> Salt + Carbon Dioxide + water.

Class 10th Ch-2 Solved Extra Question Answers Q2.

Ans:- The gas evolved at the anode during electrolysis of brine is chlorine.

When chlorine gas is passed through dry Ca(OH)2 Y produces bleaching powder (z) used for disinfecting drinking water.

Ca(OH)2 + Cl2 —–> CaOCl2 + H2O

since Y and Z are calcium salts, therefore X is also a calcium salt and is calcium Carbonate. CaCO3 + 2HCl —-> CaCl2 + CO2 + H2O

Ca(OH)2 + CO2 —–> CaCO3 + H2O

HOTS (Higher order thinking skills)

Q1. Why acetic acid is called weak aid though there are four hydrogen atoms in the Molecule?

Ans:- Acetic acid has 4 hydrogen atoms but only one hydrogen atom is released as H+ ion in the solution, that’s why acetic acid is a weak acid.

Class 10th Ch-2 Solved Extra Question Answers Q2. hots

Ans:- The Baker must be forgotten to add baking powder in cake. Baking powder is the mixture of baking soda and an eaidable tartaric acid. When Baking powder is added with water then sodium Hydrogen carbonate reacts with the Tartaric acid and CO2 gas evolved that makes the cake rise and also becomes soft and Spongy.

Class 10th Ch-2 Solved Extra Question Answers Q3. Hots

Ans:- Here compound A is Sodium Hydrogen Carbonate.

In the first case:- It is used in fire Extinguisher because it produces CO2 gas on reaction with Acid. H2SO4 + 2NaHCO3 —-> Na2SO4 + 2H2O + 2CO2

In the Second case, It is also used as Anacid because it neutralizes the Excess HCl releases during Overeating in our Stomach. NaHCO3 + HCl —-> NaCl + H2O + CO2.

In the third case, It is also used in the making of Bakery items, Because when it reacts with the acid it produces CO2 (g). Which makes the cakes and Bread Soft and Spongy.

WoW..! Now we have just completed with the Class 10th Ch-2 Solved Extra Question Answers. Now, this is the time to solve the Practice-Based Questions of this chapter. I have already created the 2 Parts of Practice Questions for this chapter. You can simply click here and download the Practice papers of this chapter and you can Solve whenever you want. Part 1 and part 2

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