#### Hydrogen Important Questions

11th Standard

Reg.No. :
•
•
•
•
•
•

Chemistry

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. Which of the following statements about hydrogen is incorrect?

(a)

Hydrogen ion, H3O+ exists freely in solution.

(b)

Dihydrogen acts as a reducing agent.

(c)

Hydrogen has three isotopes of which tritium is the most common.

(d)

Hydrogen never acts. as cation in ionic salts

2. Non-stoichiometric hydrides are formed by

(a)

(b)

carbon, nickel

(c)

manganese, lithium

(d)

nitrogen, chlorine

3. 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

4. The number of neutrons in  hydrogen atom is ___________.

(a)

three

(b)

two

(c)

one

(d)

zero

5. _____________ is known as heavy hydrogen.

(a)

protium

(b)

deuterium

(c)

tritium

(d)

both a and b

6. 5 x 2 = 10
7. Explain why hydrogen is not placed with the halogen in the periodic table.

8. 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?

9. Write short notes on Deuterium.

10. Which is the radio active isotope of Hydrogen? Write a note on it.

11. Give two uses of Tritium.

12. 5 x 3 = 15
13. Hydrogen peroxide can function as an oxidising agent as well as reducing agent. substantiate this statement with suitable examples.

14. What is water-gas shift reaction?

15. Distinguish between (ii) temporary hardness and permanent hardness.

16. Mention any two biological effects of D2O.

17. Name the salts that lead to the formation of permanent hardness in water can you remove permanent hardness by boiling?

18. 4 x 5 = 20
19. An isotope of hydrogen (A) reacts with diatomic molecule of element which occupies group number 16 and period number 2 to give compound (B) is used as a moderator in nuclear reaction. (A) adds on to a compound ( C), which has the molecular formula C3H6 to give (D). Identify A, B, C and D.

20. Compare the structures of H2O and H2O2 .

21. Why hydrogen behaves both as' a halogen and as an alkali metal?

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