1. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:

2. In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:

3. The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of

4. A chemical reaction does not involve:

5. One of the following processes does not involve a chemical reaction. That is:

6. When ferrous sulfate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in color from:

7. Which of the following gases is used in the storage of fat and oil containing foods for a long time?

8. Following is given a diagram showing an experimental set-up:

The given set-up is used to carry out:

9. The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:

10. The chemical reaction between Hydrogen sulphide and iodine to give Hydrogen iodide and sulphur is given below:

The reducing and oxidizing agents involved in this redox reaction are:

11. What happens when lead nitrate reacts with potassium iodide?

12.  Which of the following does show an oxidation reaction?

13. A student adds lead and silver to two different test tubes containing an equal amount of copper sulphate solution. The student observes that the color of the solution in the test tube with lead changes. What explains the change in the colour of the solution?

14. A student writes a chemical equation of the reaction between carbon monoxide and hydrogen.

CO2 + 2H2 → CH3OH

How can the reaction be classified?

15. A researcher adds barium hydroxide to hydrochloric acid to form a white-colored barium chloride. Which option gives the balanced chemical equation of the reaction?

16. Give the ratio in which hydrogen and oxygen are present in water by volume.

17. A student performs an experiment to form aluminium chloride from aluminium and chlorine.Which options give the chemical equation of the reaction?

18. Which one of the following processes involve chemical reactions?

19. Which of the following is Not True with respect to the neutralisation reaction?

20. The following reaction is an example of a
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction