Acids, Bases and Salts Science - Acids, Bases and Salts

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?

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

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.

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

1. Litmus.
2. Turmeric.
3. Vanilla essence.
4. Petunia leaves.

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

1. Marble.
2. Limestone.
3. Baking soda.
4. Lime.

Which of the following statements is true for acids?

1. Bitter and change red litmus to blue.
2. Sour and change red litmus to blue.
3. Sour and change blue litmus to red.
4. Bitter and change blue litmus to red.

Which of the following statements is not correct?

1. All metal carbonates react with acid to give a salt, water and carbon dioxide.
2. All metal oxides react with water to give salt and acid.
3. Some metals react with acids to give salt and hydrogen.
4. Some non metal oxides react with water to form an acid.

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.

1. 1 and 3
2. 2 and 3
3. 1 and 4
4. 2 and 4

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 prepared 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?

What will be the action of the following substances on 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 prepared 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?

A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also a by–product 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.

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.

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 and why does it show such a behaviour? Give the reaction involved.

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?

What happens when nitric acid is added to egg shell?

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

What happens when nitric acid is added to egg shell?

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.

Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for 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 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.

In the following schematic diagram for the preparation of hydrogen gas as shown in 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.

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

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.

In the following schematic diagram for the preparation of hydrogen gas as shown in 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.

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

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.