Materials: Metals and non-metals Worksheet-2

Materials: Metals and non-metals Worksheet-2

11. What is the product formed when sulphur reacts with oxygen?

A. Sulphuric acid                          B. Sulphur trioxide

C. Sulphurous acid                      D. Sulphur dioxide

12. When sulphur dioxide is dissolve in water the product formed is -

A. Sulphur                                      B. Sulphur trioxide

C. Sulphuric acid                          D. Sulphurous acid

13. What is the chemical formula of sodium sulphite?

A. NaHSO_­3        B. Na₂SO₃        C. Na₂SO₄         D. Na₂S

14. The aqueous solution of carbon dioxide will change the colour of litmus paper to ____.

A. Red                B. Blue               C. Yellow           D. Green

15. Oxides of non metals are ____ in nature

A. Basic                                          B. Acidic

C. Neutral                                      D. All of these

16. Sodium metal is stored in-

A. Water            B. Alcohol          C. Kerosene       D. Ether

17. Which of the following metal reacts vigorously with oxygen and water?

A. Aluminium                               B. Potassium

C. Calcium                                     D. Magnesium

18. Which non-metal catches fire if exposed to air?

A. Sodium                                      B. Phosphorous

C. Calcium                                     D. Uranium

19. What is the chemical formula of Cuppric sulphide?

A. CuSO₄           B. CuS                C. Cu₂S               D. Cu₂S₂O₃

20. Which gas is produced when metals react with acids?

A. Oxygen                                       B. Nitrogen

C. Hydrogen                                  D. Carbon dioxide

Answer:

11. D

Explanation: S + O₂ → SO₂

When sulphur is burnt in air or oxygen sulphur dioxide gas is formed.

12. C

Explanation: Sulphur dioxide dissolves in water producing sulphurous acid.

13. B

Explanation: NaHSO₃ is sodium bisulphite, Na­₂SO₃ is sodium sulphite, Na­₂SO₄ is sodium sulphate, Na₂S is sodium sulphide

14. A

Explanation: The aqueous solution of carbon dioxide is acidic in nature hence it will change the colour of litmus paper to red.

Acids turn blue litmus red.

15. B

16. C

Explanation: Sodium is highly reactive and on exposure to air its surface gets tarnished hence it is kept in kerosene.

17. B

Explanation: Potassium reacts vigorously with oxygen and water forming its oxide and hydroxide. Large amount of energy is released in the reaction

18. B

Explanation: Phosphorous readily catches fire in air giving dense fumes of Phosphorous pentoxide hence is kept in water.

19. B

Explanation: CuSO₄  is copper sulphate, CuS is cupric sulphide, Cu₂S is cuprous sulphide, Cu₂S₂O₃ is cupric thiosulphate

20. C

Explanation:

Hydrogen gas is released when metals react with acids.