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#### Important one marks questions Hydrogen

11th Standard

Reg.No. :
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Chemistry

Answer each of the following questions
Time : 00:40:00 Hrs
Total Marks : 50

Part - A

50 x 1 = 50
1. HF has ______ hydrogen bond.

(a)

intramolecular

(b)

intermolecular

(c)

intrastellar

(d)

interstellar

2. Acetic acid exist as a __________

(a)

monomer

(b)

dimer

(c)

trimer

(d)

octamer

3. What is the dihedral angle of H2O2 in gas and solid phase?

(a)

111.5°and 90.2°

(b)

115.1°and 92°

(c)

92° and 115.1°

(d)

902° and 111.5°

4. H2O2 acts as

(a)

oxidising agent

(b)

reducing agent

(c)

bleaching agent

(d)

All of these

5. The reaction H2O2 ➝ H2O+O2 represents,

(a)

Oxidation of H2O2

(b)

reduction of H2O

(c)

disproponation of oxygen

(d)

acidic nature of H2O2

6. H2O and H2O2 resemble in

(a)

Bond angle

(b)

Hybridization of oxygen

(c)

Structure

(d)

Oxidation state of oxygen

7. Statement I : The 0-0 bond length in H2O2 is shorter than that of O2F2 .
Statement II : H2O2 is an ionic compound.

(a)

Both statement I and II are true and statement II explains statement I

(b)

Both statement I and II are true but statement II does not explains statement I

(c)

Statement I is true but statement II is false

(d)

Both the statements are false.

8. Ionic hydrides are usually

(a)

good conductors of electricity in solid state

(b)

volatile

(c)

non-crystalline

(d)

stoichiometric compounds

9. Intermolecular H-bonding is present in __________

(a)

HF

(b)

H2O

(c)

C2H5OH

(d)

All of these

10. 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

11. Which one of the following bond is stronger?

(a)

Covalent

(b)

H-bond

(c)

Vanderwaal's force

(d)

All of these

12. Intramolecular H-bonding is present in _________

(a)

o-nitrophenol

(b)

salicylic acid

(c)

salicylaldlehyde

(d)

all of these

13. The element which does not contain a neutron is

(a)

hydrogen

(b)

helium

(c)

chlorine

(d)

none of the above

14. The number of electrons, protons and neutrons in protium, deuterium and tritium are respectively

(a)

1, 1,0; 1, 1, 1 ; 1, 1,2

(b)

1, 1, 1 ; 1, 1,0; 1, 1,2

(c)

1,1,2; 1, 1,0; 1, 1, 1

(d)

1,1,1; 1, 1,0; 1, 1,2

15. Among the isotopes of hydrogen, which has higher mass and radio active?

(a)

Protium

(b)

Tritium

(c)

Deuterium

(d)

both deuterium and tritium

16. Choose the incorrect statement:

(a)

The boiling points of both deuterium and tritium are higher than that of protium.

(b)

The inter nuclear distances between the two bonded atoms are different in all the isotopes.

(c)

Enthalpy of dissociation is high in tritium

(d)

both (b) and (c)

17. Normal hydrogen consists of:

(a)

75% ortho form and 25% para form

(b)

25% ortho form and 75% para form

(c)

80% ortho form and 20% para form

(d)

20% ortho form and 80% para form

18. Choose the correct statement with regard to ortho and para hydrogen.
1. Both have similar chemical properties but differ in.some physical properties.
2. The boiling points of normal, ortho and para hydrogens are the same.
3. The nuclear spin in both forms are the same.
4. Para hydrogen has zero magnetic moment.

(a)

1,2

(b)

1,4

(c)

2, 3

(d)

2, 4

19. CO2 + K2CO3 + H2O $\rightarrow$ X. The product X is:

(a)

KHCO3

(b)

CO2

(c)

H2CO3

(d)

KOH

20. Which of the following dissociate more readily?

(a)

H2O

(b)

D2O

(c)

T2O

(d)

H2 all dissociate to the same extent

21. Hydrogen resembles halogens in many respects for which several factors are responsible of the following factors which one is most important in this respect.

(a)

Its tendency to lose an electron and form a cation.

(b)

Its tendency to gain an electron in its valence shell to attain stable electronic configuration.

(c)

Its low electron gain enthalpy.

(d)

Its small size

22. Metal hydrides are ionic,covalent or molecular in nature. Among LiH, NaH, KH, RbH, CsH the correct order of increasing ionic character is:

(a)

LiH >NaH > CsH > KH > RbH

(b)

LiH <NaH < KH < RbH < CsH

(c)

RbH > CsH > NaH > KH > LiH

(d)

NaH > CsH > RbH> LiH > KH

23. Which of the following is electron precise hydride?

(a)

B2H6

(b)

NH3

(c)

H20

(d)

CH4

24. Consider the reactions:
(i) H2O2 + 2HI $\rightarrow$ 12+ 2H2O
(ii) HOCI + H2O2 $\rightarrow$ H3O++ CI- + O2
Which of the following statements is correct about H2O2 with reference to the above reactions?

(a)

an oxidising agent in both (i) and (ii)

(b)

an oxidising agent in (i) and reducing agent in (ii)

(c)

a reducing agent in (i) and oxidising agent in (ii)

(d)

a reducing agent in both (i) and (ii)

25. Which of the following reactions increases the production of di-hydrogen from sYnthesis gas?

(a)

$CH_4(g)+H_2O(g)\xrightarrow[Ni]{1270k}CO(g)+3H_2(g)$

(b)

$C(s)+H_2O(g)\xrightarrow{1270k}CO(g)+H_2(g)$

(c)

$CO(g)+H_2O(g)\xrightarrow[catalyst]{673k}CO(s)+H_2(g)$

(d)

$C_2H_6(g)+2H_2O(g)\xrightarrow[Ni]{1270k}2CO(g)+5H_2(g)$

26. When sodium peroxide is treated with dilute sulphuric acid.the products are

(a)

sodium sulphate and water

(b)

sodium sulphate and oxygen

(c)

sodium sulphate, hydrogen and oxygen

(d)

sodium sulphate and hydrogen peroxide

27. Which of the following compounds is a peroxide?

(a)

KO2

(b)

BaO2

(c)

MnO2

(d)

NO2

28. $Ag_2O+H_2O_2\rightarrow2Ag+H_2O+O_2$In this reaction H202 acts as

(a)

reducing agent

(b)

oxidising agent

(c)

bleaching agent

(d)

none of these

29. Bond angles in H -O-Hand H -O-Oin water and H2O2 respectively are:

(a)

104° 5',104° 5'

(b)

94.8°, 94.8°

(c)

104° 5', 94.8°

(d)

94.8°,104.5°

30. When zeolite, which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions are exchanged with:

(a)

H+ ions

(b)

Ca+2 ions

(c)

SO4-2 ions

(d)

Mg+2 ions

31. The reagent used for softening of the temporary hardness of water is/are
(i) Ca3 (PO4)2     (ii) Ca(OH)2          (iii) Na2CO3    (iv) NaOCI

(a)

(ii) and (iii)

(b)

(i) and (iii)

(c)

(ii) and (iv)

(d)

(i) and (iv)

32. In which.of the following reactions H2O2 act as a reducing agent?
(i)H2O2 + 2H+ + 2e $\rightarrow$ 2H2O
(ii) H2O2 - 2e $\rightarrow$ O2 + 2H+
(iii) H2O2 + 2e $\rightarrow$ 2OH-
(iv) H2O2 + 2OH- - 2e $\rightarrow$ O2 + 2H2O

(a)

(ii) and (iv)

(b)

(i) and (ii)

(c)

(iii) and (iv)

(d)

(i) and (iii)

33. Which one of the following element mostly present in the sun and the stars?

(a)

Hydrogen

(b)

Lithium

(c)

Helium

(d)

Beryllium

34. ------is the most abundant 90% of all atoms

(a)

Lithium

(b)

Hydrogen

(c)

Oxygen

(d)

Silicon

35. At room temperature normal hydrogen consists of -------------

(a)

25% ortho form + 75% para form

(b)

50% ortho form + 50% para form

(c)

75% ortho form + 25% para form

(d)

60% ortho form + 40% para form

36. Which one of the metal is used to convert para hydrogen into ortho hydrogen?

(a)

Copper

(b)

Aluminium

(c)

Sodium

(d)

Platinum

37. Consider the following statements.
(i) In ortho form of hydrogen molecule, the nuclear spins are opposed to each other.
(ii) The magnetic moment of para hydrogen is twice that of ortho hydrogen.
(iii) By passing an electric discharge, para hydrogen can be converted into ortho hydrogen.
Which of the above statement is/are not correct?

(a)

(i) only

(b)

(iii) only

(c)

(i) and (ii)

(d)

(ii) and (iii)

38. Which of the following is not used in the conversion of para hydrogen into ortho hydrogen?

(a)

by heating more than 800°C

(b)

by passing an electric discharge

(c)

by mixing with atomic hydrogen

(d)

by mixing with diamagnetic molecules

39. The magnetic moment of para hydrogen is -------

(a)

one

(b)

zero

(c)

twice

(d)

maximum

40. Which one of the following does not contain neutron?

(a)

ordinary hydrogen

(b)

Heavy hydrogen

(c)

(d)

Deuterium

41. Which of the following is used in illumination of wrist watches?

(a)

Phosphorous

(b)

(c)

Tritium

(d)

Deuterium

42. Which one of the following is used to study the movements of ground water?

(a)

Deuterium

(b)

Protium

(c)

Tritium

(d)

HD

43. By which rays nuclear reactions are induced in upper atmosphere to produce tritium?

(a)

α-rays

(b)

β-rays

(c)

$\gamma$-rays

(d)

cosmic rays

44. Which of the following is produced by bombardment of neutrons with lithium?

(a)

Deuterium

(b)

Protium

(c)

Tritium

(d)

Beryllium

45. Consider the following statements.
(i) Tritium is a beta emitting radioactive isotope of hydrogen.
(ii) Deuterium is known as heavy hydrogen.
(iii) Deuterium is used in emergency exit signs.
Which of the following statement is/are not correct?

(a)

(i) only

(b)

(iii) only

(c)

(i) and (ii)

(d)

(i), (ii) and (iii)

46. Which of the following mixture of gases is called water gas?

(a)

CO2(g)+ H2(g)

(b)

CO(g)+ N2(g)

(c)

CO(g)+ H2(g)

(d)

N2(g)+ H2(g)

47. Consider the following statements.
(i) Hydrogen is a colourless, odourless, tasteless heavy and highly inflammable gas.
(ii) Hydrogen is a good reducing agent.
(iii) Hydrogen can be liquefied under low pressure and high temperature.
Which of the above statements is/are not correct?

(a)

(i) only

(b)

(ii) only

(c)

(i) and (iii)

(d)

(ii) and (iii)

48. The products formed during the cracking long chain hydrocarbon C6H12 are-----------

(a)

CO2 + H2O

(b)

CO + H2

(c)

C6H10 + H2

(d)

C6H6 + 3H2

49. Which one of the following is manufactured in Haber's process?

(a)

SO3

(b)

NH3

(c)

N2

(d)

H2

50. Hydrogen combines with carbon monoxide in the presence of copper catalyst will synthesise-------

(a)

Ethanol

(b)

Methane

(c)

Methanol

(d)

Methanal