Hydrogen Practice Questions - DPP for JEE

 Page 1


1. (c) The correct option is (c). In H
2
O, hydrogen has + 1 oxidation no.
In CaH
2
, hydrogen has – 1 oxidation no.
2. (c) Occlusion is the phenomenon of adsorption of hydrogen by metal.
3. (d) Heavy water is stable.
4. (a) A fusion reaction is difficult to occur because positively charged
nuclei repel each other. At very high temperature of the order of
10
6
 to 10
7
 K, the nuclei may have sufficient energy to overcome
the repulsive forces and fuse. It is for this reason, fusion reactions
are also called thermonuclear reactions. Hence, hydrogen can be
fused to form helium at high temperature and high pressure.
5. (b)
In this reaction H
–
 acts as bronsted base as it accepts one proton (H
+
)
from H
2
O and form H
2
.
6. (d) The water gas is a combination of carbon and hydrogen. It is used
in manufacturing of methanol.
7. (a) Elements of group 7, 8 and 9 of d-block do not form hydrides at
all. The inability of metals of group 7, 8 and 9 of periodic table to
form hydrides is referred to as hydrides gap of d-block. In these
compounds H atoms are supposed to occupy interstitial position in
the metal lattices. They are also called non-stoichiometric
hydrides.
8. (a) Cu + 4HNO
3
(conc.) Cu(NO
3
)
2
 + 2NO
2
 + 2H
2
O
Page 2


1. (c) The correct option is (c). In H
2
O, hydrogen has + 1 oxidation no.
In CaH
2
, hydrogen has – 1 oxidation no.
2. (c) Occlusion is the phenomenon of adsorption of hydrogen by metal.
3. (d) Heavy water is stable.
4. (a) A fusion reaction is difficult to occur because positively charged
nuclei repel each other. At very high temperature of the order of
10
6
 to 10
7
 K, the nuclei may have sufficient energy to overcome
the repulsive forces and fuse. It is for this reason, fusion reactions
are also called thermonuclear reactions. Hence, hydrogen can be
fused to form helium at high temperature and high pressure.
5. (b)
In this reaction H
–
 acts as bronsted base as it accepts one proton (H
+
)
from H
2
O and form H
2
.
6. (d) The water gas is a combination of carbon and hydrogen. It is used
in manufacturing of methanol.
7. (a) Elements of group 7, 8 and 9 of d-block do not form hydrides at
all. The inability of metals of group 7, 8 and 9 of periodic table to
form hydrides is referred to as hydrides gap of d-block. In these
compounds H atoms are supposed to occupy interstitial position in
the metal lattices. They are also called non-stoichiometric
hydrides.
8. (a) Cu + 4HNO
3
(conc.) Cu(NO
3
)
2
 + 2NO
2
 + 2H
2
O
9. (c) Hydrogen is not used in the synthesis of hydroquinone and tartaric
acid.
10. (b) In the structure of ice each molecule of H
2
O is surrounded by three
H
2
O molecules in hexagonal honey comb manner which results an
open cage like structure. As a result there are a number of 'hole' or
open spaces. In such a structure lesser number of molecules are
packed per ml. When ice melts a large no. of hydrogen bonds are
broken. The molecules therefore move into the holes or open
spaces and come closer to each other than they were in solid state.
This result sharp increase in the density. Therefore ice has lower
density than water.
11. (b) HO
3
SOOSO
3
H(aq)
(aq) + 2H
+
(aq) + H
2
O
2
(aq)
12. (a) In one electron species, such as H-atom, the energy of orbital
depends only on the principal quantum number, n.
Hence answer (d)
i.e. is < 2s = 2p < 3s = 3p = 3d < 4s
= 4p ? 4d = 4g
13. (d) Chlorine has lone pair which it can donate to form coordinate bond
while hydrogen cannot.
14. (a) MgCO
3
 is insoluble in water.
15. (d) Very pure hydrogen can be prepared by the action of water on
sodium hydride.
NaH + H
2
O NaOH  +  H
2
(very pure Hydrogen)
16. (a) H
2
O
2
 acts as a reducing agent only in presence of strong oxidising
Page 3


1. (c) The correct option is (c). In H
2
O, hydrogen has + 1 oxidation no.
In CaH
2
, hydrogen has – 1 oxidation no.
2. (c) Occlusion is the phenomenon of adsorption of hydrogen by metal.
3. (d) Heavy water is stable.
4. (a) A fusion reaction is difficult to occur because positively charged
nuclei repel each other. At very high temperature of the order of
10
6
 to 10
7
 K, the nuclei may have sufficient energy to overcome
the repulsive forces and fuse. It is for this reason, fusion reactions
are also called thermonuclear reactions. Hence, hydrogen can be
fused to form helium at high temperature and high pressure.
5. (b)
In this reaction H
–
 acts as bronsted base as it accepts one proton (H
+
)
from H
2
O and form H
2
.
6. (d) The water gas is a combination of carbon and hydrogen. It is used
in manufacturing of methanol.
7. (a) Elements of group 7, 8 and 9 of d-block do not form hydrides at
all. The inability of metals of group 7, 8 and 9 of periodic table to
form hydrides is referred to as hydrides gap of d-block. In these
compounds H atoms are supposed to occupy interstitial position in
the metal lattices. They are also called non-stoichiometric
hydrides.
8. (a) Cu + 4HNO
3
(conc.) Cu(NO
3
)
2
 + 2NO
2
 + 2H
2
O
9. (c) Hydrogen is not used in the synthesis of hydroquinone and tartaric
acid.
10. (b) In the structure of ice each molecule of H
2
O is surrounded by three
H
2
O molecules in hexagonal honey comb manner which results an
open cage like structure. As a result there are a number of 'hole' or
open spaces. In such a structure lesser number of molecules are
packed per ml. When ice melts a large no. of hydrogen bonds are
broken. The molecules therefore move into the holes or open
spaces and come closer to each other than they were in solid state.
This result sharp increase in the density. Therefore ice has lower
density than water.
11. (b) HO
3
SOOSO
3
H(aq)
(aq) + 2H
+
(aq) + H
2
O
2
(aq)
12. (a) In one electron species, such as H-atom, the energy of orbital
depends only on the principal quantum number, n.
Hence answer (d)
i.e. is < 2s = 2p < 3s = 3p = 3d < 4s
= 4p ? 4d = 4g
13. (d) Chlorine has lone pair which it can donate to form coordinate bond
while hydrogen cannot.
14. (a) MgCO
3
 is insoluble in water.
15. (d) Very pure hydrogen can be prepared by the action of water on
sodium hydride.
NaH + H
2
O NaOH  +  H
2
(very pure Hydrogen)
16. (a) H
2
O
2
 acts as a reducing agent only in presence of strong oxidising
agents (i.e., MnO
4
? –
) in acidic as well as alkaline medium.
 
17. (d) Polyphosphates (e.g., sodium hexa metaphosphate) form soluble
complexes with cations such as Ca
2+
, Mg
2+
 and so they are used as
water softening agents.
            
18. (c) Ortho and para forms of hydrogen resemble in their  chemical
properties.
19. (c) has oxidizing and reducing properties both.
20. (c) CH
4
(g) + H
2
O(g) CO + 3H
2
Mixture of CO and H
2
 is called water gas.
21. (1.7)Normality of 10V of H
2
O
2
   ? N= 1.78
22. (0.01)  22.4 L of H
2
 at STP = 1 mole of 
 0.224 L of H
2
 at STP  =  = 0.01 moles.
23. (1) Only one water molecule which is outside the coordination sphere
is hydrogen bonded. Other four molecules of H
2
O are coordinated.
24. (25.5) Molecular weight of H
2
O
2
 = 34
Equivalent weight of H
2
O
2
 = 17
 1 L of 1 N H
2
O
2
 = 17 g of H
2
O
2
 1 L of 1.5 N H
2
O
2
 = 1.5 × 17 = 25.5 g of H
2
O
2
25. (3.2)Strength of the solution = 34 g/L
1 L of the solution contains 34 g of H
2
O
2
Page 4


1. (c) The correct option is (c). In H
2
O, hydrogen has + 1 oxidation no.
In CaH
2
, hydrogen has – 1 oxidation no.
2. (c) Occlusion is the phenomenon of adsorption of hydrogen by metal.
3. (d) Heavy water is stable.
4. (a) A fusion reaction is difficult to occur because positively charged
nuclei repel each other. At very high temperature of the order of
10
6
 to 10
7
 K, the nuclei may have sufficient energy to overcome
the repulsive forces and fuse. It is for this reason, fusion reactions
are also called thermonuclear reactions. Hence, hydrogen can be
fused to form helium at high temperature and high pressure.
5. (b)
In this reaction H
–
 acts as bronsted base as it accepts one proton (H
+
)
from H
2
O and form H
2
.
6. (d) The water gas is a combination of carbon and hydrogen. It is used
in manufacturing of methanol.
7. (a) Elements of group 7, 8 and 9 of d-block do not form hydrides at
all. The inability of metals of group 7, 8 and 9 of periodic table to
form hydrides is referred to as hydrides gap of d-block. In these
compounds H atoms are supposed to occupy interstitial position in
the metal lattices. They are also called non-stoichiometric
hydrides.
8. (a) Cu + 4HNO
3
(conc.) Cu(NO
3
)
2
 + 2NO
2
 + 2H
2
O
9. (c) Hydrogen is not used in the synthesis of hydroquinone and tartaric
acid.
10. (b) In the structure of ice each molecule of H
2
O is surrounded by three
H
2
O molecules in hexagonal honey comb manner which results an
open cage like structure. As a result there are a number of 'hole' or
open spaces. In such a structure lesser number of molecules are
packed per ml. When ice melts a large no. of hydrogen bonds are
broken. The molecules therefore move into the holes or open
spaces and come closer to each other than they were in solid state.
This result sharp increase in the density. Therefore ice has lower
density than water.
11. (b) HO
3
SOOSO
3
H(aq)
(aq) + 2H
+
(aq) + H
2
O
2
(aq)
12. (a) In one electron species, such as H-atom, the energy of orbital
depends only on the principal quantum number, n.
Hence answer (d)
i.e. is < 2s = 2p < 3s = 3p = 3d < 4s
= 4p ? 4d = 4g
13. (d) Chlorine has lone pair which it can donate to form coordinate bond
while hydrogen cannot.
14. (a) MgCO
3
 is insoluble in water.
15. (d) Very pure hydrogen can be prepared by the action of water on
sodium hydride.
NaH + H
2
O NaOH  +  H
2
(very pure Hydrogen)
16. (a) H
2
O
2
 acts as a reducing agent only in presence of strong oxidising
agents (i.e., MnO
4
? –
) in acidic as well as alkaline medium.
 
17. (d) Polyphosphates (e.g., sodium hexa metaphosphate) form soluble
complexes with cations such as Ca
2+
, Mg
2+
 and so they are used as
water softening agents.
            
18. (c) Ortho and para forms of hydrogen resemble in their  chemical
properties.
19. (c) has oxidizing and reducing properties both.
20. (c) CH
4
(g) + H
2
O(g) CO + 3H
2
Mixture of CO and H
2
 is called water gas.
21. (1.7)Normality of 10V of H
2
O
2
   ? N= 1.78
22. (0.01)  22.4 L of H
2
 at STP = 1 mole of 
 0.224 L of H
2
 at STP  =  = 0.01 moles.
23. (1) Only one water molecule which is outside the coordination sphere
is hydrogen bonded. Other four molecules of H
2
O are coordinated.
24. (25.5) Molecular weight of H
2
O
2
 = 34
Equivalent weight of H
2
O
2
 = 17
 1 L of 1 N H
2
O
2
 = 17 g of H
2
O
2
 1 L of 1.5 N H
2
O
2
 = 1.5 × 17 = 25.5 g of H
2
O
2
25. (3.2)Strength of the solution = 34 g/L
1 L of the solution contains 34 g of H
2
O
2
200 mL of the solution contains × 200 = 6.8  g of H
2
O
2
68 g of H
2
O
2
 gives 32 g of O
2
6.8 g of H
2
O
2
 gives = × 6.8 = 3.2 g of O
2