Acids, Bases & Salts (C10)

A compound X of sodium is used as an antacid

A compound ‘X’ of sodium is used as an antacid and it decomposes on strong heating.

1. Name the compound ‘X’ and give its chemical formula.
2. Write a balanced chemical equation to represent the decomposition of ‘X’.
3. Give one use of compound ‘X’ besides an antacid.

You are provided with 90 mL of distilled water

You are provided with 90 mL of distilled water and 10 mL of concentrated sulphuric acid to prepare dilute sulphuric acid.

1. What is the correct way of preparing dilute sulphuric acid? Give reason.
2. How will the concentration of H₃O⁺ ions change on dilution?

While diluting an acid, why is it recommended that the acid

(a) While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid ?

(b) Dry hydrogen chloride gas does not change the colour of dry litmus paper. Why ?

How is sodium hydroxide manufactured in industries

How is sodium hydroxide manufactured in industries ? Name the process. In this process a gas X is formed as by-product. This gas reacts with lime water to give a compound Y, which is used as a bleaching agent in the chemical industry. Identify X and Y and write the chemical equation of the reactions involved.

What are amphoteric oxides

What are amphoteric oxides ? Give an example. Write balanced chemical equations to justify your answer.

For the preparation of cakes, baking powder is used

(a) For the preparation of cakes, baking powder is used. If at home your mother uses baking soda instead of baking powder, how will it affect the taste of the cake and why?

(b) How is baking soda be converted into baking powder?

(c) What makes the cake soft and spongy?

In the electrolysis of water

In the electrolysis of water,

1. Name the gas collected at anode and cathode?
2. Why is the volume of gas collected at one electrode double than the other?
3. What would happen if dil H₂SO₄ is not added to water?

pH has a great importance in our daily life

"pH has a great importance in our daily life". Explain by giving three examples.

A compound which is prepared from gypsum has the property of hardening

A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identify the compound and write its chemical formula. Write the chemical equation for its preparation. Mention any one use of the compound.

1 g of solid sodium chloride is taken in a clean and dry test tube

1 g of solid sodium chloride is taken in a clean and dry test tube and 2 mL of conc. sulphuric acid is added to it. If the gas evolved is tested first with dry and then with wet blue litmus paper, in which case will the litmus paper change colour? Give reason for your answer. What inference can be drawn about the nature of the evolved gas ? Support your answer with chemical equation for the reaction.

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.