NCERT Exemplar solutions for Science [English] Class 10 chapter 2 - Acids, Bases and Salts [Latest edition]

What happens when a solution of an acid is mixed with a solution of a base in a test tube?

1. The temperature of the solution increases
2.  The temperature of the solution decreases
3.  The temperature of the solution remains the same
4. Salt formation takes place

An aqueous solution turns red litmus solution blue. Excess addition of which of the following solutions would reverse the change?

During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to ______ 

Which of the following salts does not contain any water of crystallisation?

Sodium carbonate is a basic salt because it is a salt of

Calcium phosphate is present in tooth enamel. Its nature is

A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue?

Which of the following gives the correct increasing order of acidic strength?

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

Sodium hydrogencarbonate when added to acetic acid evolves a gas. Which of the following statements are true about the gas evolved?

1.  It turns lime water milky
2. It extinguishes a burning splinter
3. It dissolves in a solution of sodium hydroxide
4. It has a pungent odour

Common salt besides being used in kitchen can also be used as the raw material for making

1. washing soda
2.  bleaching powder
3.  baking soda
4.  slaked lime

One of the constituents of baking powder is sodium hydrogencarbonate. The other constituent is :

To protect tooth decay, we are advised to brush our teeth regularly. The nature of the tooth paste commonly used is

Which of the following statements is correct about an aqueous solution of an acid and of a base?

1.  Higher the pH, stronger the acid
2. Higher the pH, weaker the acid
3. Lower the pH, stronger the base
4.  Lower the pH, weaker the base

The pH of the gastric juices released during digestion is

Which of the following phenomena occur when a small amount of acid is added to water?

1. Ionisation
2. Neutralisation
3. Dilution
4. Salt formation

Which one of the following can be used as an acid- base indicator by a visually impared student?

Which of the following substance will not give carbon dioxide on treatment with dilute acid?

Which of the following is acidic in nature?

In an attempt to demonstrate electrical conductivity through an electrolyte, the apparatus setup. Which among the following statement(s) is(are) correct?

1. Bulb will not glow because electrolyte is not acidic
2. Bulb will glow because NaOH is a strong base and furnishes ions for conduction.
3. Bulb will not glow because circuit is incomplete
4. Bulb will not glow because it depends upon the type of electrolytic solution

Which of the following is used for dissolution of gold?

Which of the following is not a mineral acid?

Which of the following is not a base? 

Which of the following statements is not correct?

Match the chemical substances given in Column (A) with their appropriate application given in Column (B)

Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper. What would be the colour obtained?

Which of the following is(are) true when HCl (g) is passed through water?

1.  It does not ionise in the solution as it is a covalent compound.
2.  It ionises in the solution
3. It gives both hydrogen and hydroxyl ions in the solution
4.  It forms hydronium ion in the solution due to the combination of hydrogen ion with water molecule

Which of the following statements is true for acids?

Which of the following are present in a dilute aqueous solution of hydrochloric acid?

Identify the correct representation of reaction occurring during chloralkali process

Match the acids given in column (A) with their correct source given in column (B)

Match the important chemicals given in Column (A) with the chemical formulae given in Column (B)

What will be the action of the following substances on blue litmus paper?

Dry HCl gas, Moistened NH₃ gas, Lemon juice, Carbonated soft drink, Curd, Soap solution.

Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting.

A student prepares solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless, how will she distinguish between the two?

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

Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for the removal of hardness of water and a gas C is evolved. The gas C when passed through lime water, turns it milky. Identify A, B and C.

In one of the industrial processes used for the manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.

Fill in the missing data in the following table

What are strong and weak acids? In the following list of acids, separate strong acids from weak acids.

Hydrochloric acid, citric acid, acetic acid, nitric acid, formic acid, sulphuric acid.

When zinc metal is treated with a dilute solution of a strong acid, a gas is evolved which is utilised in the hydrogenation of oils. Name the gas evolved. Write the chemical equation of the reaction involved and also write a test to detect the gas formed.

In the following schematic diagram for the preparation of hydrogen gas as shown in the figure, what would happen if following changes are made?

1. In place of zinc granules, same amount of zinc dust is taken in the test tube
2. Instead of dilute sulphuric acid, dilute hydrochloric acid is taken
3. In place of zinc, copper turnings are taken
4. Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.

For making cake, baking powder is taken. If at home your mother uses baking soda instead of baking powder in cake,

1. how will it affect the taste of the cake and why?
2. how can baking soda be converted into baking powder?
3. what is the role of tartaric acid added to baking soda?

A metal carbonate X on reacting with an acid gives a gas which when passed through a solution Y gives the carbonate back. On the other hand, a gas G that is obtained at anode during electrolysis of brine is passed on dry Y, It gives a compound Z, used for disinfecting drinking water. Identity X, Y, G and Z.

A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also of chloralkali process. Identify B What type of reaction occurs when B is treated with an acidic oxide ? Write a balanced chemical equation for one such solution.

A sulphate salt of Group 2 element of the Periodic Table is a white, soft substance which can be moulded into different shapes by making its dough. When this compound is left in open for some time, it becomes a solid mass and cannot be used for moulding purposes. Identify the sulphate salt. Why does it show such a behaviour? Give the reaction involved.

Identify the compound Y on the basis of the reactions given below. Also write the name and chemical formulae of A, B and C.