#### Hydrogen - Important Question Paper

11th Standard

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 50

Part A

10 x 1 = 10
1. Non-stoichiometric hydrides are formed by

(a)

(b)

carbon, nickel

(c)

manganese, lithium

(d)

nitrogen, chlorine

2. If a body of a fish contains 1.2 g hydrogen in its total body mass, if all the hydrogen is replaced with deuterium then the increase in body weight of the fish will be

(a)

1.2 g

(b)

2.4 g

(c)

3.6 g

(d)

$\sqrt{4.8}$g

3. The hardness of water can be determined by volumetrically using the reagent

(a)

sodium thio sulphate

(b)

potassium permanganate

(c)

hydrogen peroxide

(d)

EDTA

4. Zeolite used to soften hardness of water is hydrated

(a)

Sodium aluminium silicate

(b)

Calcium aluminium silicate

(c)

Zinc aluminium borate

(d)

Lithium aluminium hydride

5. A commercial sample of hydrogen peroxide marked as 100 volume H2O2, it means that

(a)

1 ml of H2O2 will give 100 ml O2 at STP

(b)

1 L of H2O2 will give 100 ml O2 at STP

(c)

1 L of H2O2 will give 22.4 L O2

(d)

1 ml of H2O2  will give 1 mole of O2 at STP

6. Intermolecular H-bonding is present in __________

(a)

HF

(b)

H2O

(c)

C2H5OH

(d)

All of these

7. The intramolecular hydrogen bonding in molecules lead to _____________

(a)

high melting point

(b)

low boiling point

(c)

high boiling point

(d)

high solubility in water

8. Which one of the following bond is stronger?

(a)

Covalent

(b)

H-bond

(c)

Vanderwaal's force

(d)

All of these

9. Intramolecular H-bonding is present in _________

(a)

o-nitrophenol

(b)

salicylic acid

(c)

salicylaldlehyde

(d)

all of these

10. The element which does not contain a neutron is

(a)

hydrogen

(b)

helium

(c)

chlorine

(d)

none of the above

11. Part B

5 x 2 = 10
12. Explain why hydrogen is not placed with the halogen in the periodic table.

13. An the cube at 0° C is placed in some liquid water at 00C, the ice cube sinks - Why? What will happen to ice at 00C placed in liquid water at 00C?

14. Discuss the three types of Covalent hydrides.

15. Predict which of the following hydrides is a gas on a solid (a) BCI (b) NaH. Give your reason.

16. Write chemical equation for the following reactions.
(i) hydrogen with tungsten (VI) oxide.
(ii) hydrogen gas and chlorine gas.

17. Part C

5 x 3 = 15
18. Explain the laboratory preparation of dihyodrogen.

19. Why is water molecule polar?

20. Distinguish between (i) hard water and soft water

21. Explain why HCl is a gas and HF is a liquid?

22. Give any two methods of preparation of H2O2.

23. Part D

3 x 5 = 15
24. Why hydrogen behaves both as' a halogen and as an alkali metal?

25. Conc. H2SO4 cannot be used for drying hydrogen gas. Why?

26. Write a note on application of hydrogen in cutting and welding purpose.