Section-A
Q.No. Solutions
1. Answer (4)
Water gas is 1 : 1 mixture of CO and H2. As this mixture is used for the synthesis of methanol and a
number of hydrocarbons, it is also known as synthesis gas.
2. Answer (3) 5 H 2 2 2 – 7 2O H O CrO Cr 3. Answer (4) H H O H O H H H O H H O H O H 4. Answer (3) PbS + 4H2O2 PbSO4 + 4H2O 5. Answer (2)
The elements of 7, 8 and 9 group do not form hydrides. This is actually known as HYDRIDE GAP.
6. Answer (4)
Nascent hydrogen is more reactive than molecular hydrogen and can be produced in situ.
7. Answer (2)
2 Ethyl anthraquinol produces H2O2 on oxidation
9
8. Answer (3)
H2O2 acting as oxidizing agent
In acidic medium
2K4[Fe(CN)6] + H2O2 + H2SO4 2K3[Fe(CN)6] + K2SO4 + H2O
H2O2 acting as reducing agent when it reacts with K3[Fe(CN)6]
In Basic medium
2K3[Fe(CN)6] + 2KOH + H2O2 2K4[Fe(CN)6] + 2H2O + O2
9. Answer (1)
Zn and Sn react with NaOH and produce hydrogen Zn 2NaOH Na2ZnO2 + H2
10. Answer (1)
Ortho and Para hydrogen have different nuclear spins
11. Answer (2)
H H –H H (Conjugate base of H )2
Hydrideion 12. Answer (2)
Na H + H — OH NaOH + H2
So the solution would be basic.
13. Answer (3)
Boiling point of water is exceptionally high due to hydrogen bonding
14. Answer (4)
Metallic hydrides are interstitial and non-stoichiometric and poor conductor of electricity.
15. Answer (2) 11.2 strength Volume M volume strength = 3.57 × 11.2 = 40 volume
16. Answer (1) 18 2 2 agent oxidising 18 2 2O 2H O O 2H 17. Answer (1)
PbO2 is not a peroxide so, it does not produce H2O2
18. Answer (1)
10 volumes of H2O2 means, 10 ml of oxygen is produced by the decomposition of 1 ml of H2O2 at STP.
19. Answer (4)
LiH is ionic hydride, while MgH2 and CuH are intermediate hydrides
20. Answer (2)
AlH3 is a Lewis acid
H– is a Lewis base in I
In II — H– accept H+ so Bronsted base
21. Answer (4)
Transition elements form interstitial hydride.
22. Answer (2)
It is deuterium oxide.
23. Answer (4)
As both ‘O’ atoms are in sp3
24. Answer (3)
This is the condition of neutrality.
25. Answer (4)
Section-B
Q.No. Solutions
1. Answer (1, 4)
Saline hydride or ionic hydrides are CaH2 and SrH2
2. Answer (2, 4)
3. Answer (1, 3)
CH4 and HCl are covalent hydride
4. Answer (1, 2)
BH3 and BeH2 exist in polymeric form
Be H H Be H H Be H H Be (BeH )2 n H H B H H B H H (BH )3 2 5. Answer (1, 2, 3)
7, 8, 9 group do not form hydride
6. Answer (3)
H2O2 act as oxidising agent for PbS
7. Answer (2, 3)
Density and viscosity of H2O2 is higher than water.
8. Answer (2, 3, 4)
Hardness of water is due to CaSO4, MgCl2 and MgSO4.
9. Answer (1, 3, 4)
Stearic acid, palmitic acid and oleic acids are long chain fatty acid and hence their sodiumsalts can participate in colloidal formation.
10. Answer (1, 2, 3 )
Na2[Na4(PO3)6] in Calgon method
Ca(OH)2 Clark’s method
Na2CO3 also used to convert soluble salt of Ca & Mg to insoluble bicarbonate
11. Answer (3, 4)
Ca(OH)2 form carbonate of Ca & Mg
12. Answer (1, 4)
Two nucleus have same spin two e– have opposite spin
13. Answer (2, 3)
On increasing ortho concentration equilibrium will shift towards right. Decreasing temp will also increase the concentration of parahydrogen and hence equilibrium will shift in forward direction.
14. Answer (1, 2, 3, 4)
Hydrogen gas can be prepared by Lene’s process, Bosh’s process, electrolysis of acidulated water and Kolbes electrolysis
15. Answer (1, 2, 3, 4)
H2O2 acts as oxidising agent, reducing agent, bleaching agent and acid
16. Answer (3) n
1.5 p
17. Answer (2, 3)
In eq, solution both ionize
Section-C
Q.No. Solutions Comprehension-I
1. Answer (2)
Bleaching action of H2O2 is due to its ability to oxidise
2. Answer (4)
Oxygen evolved = 30 × 1000 = 3 × 104 mol = 30 litre
3. Answer (3)
Pure H2O2 is a weak acid
Comprehension-II 1. Answer (4) Al4C3 + D2O CD4 + Al(OD)3 2. Answer (1) N2O5 + D2O DNO3 3. Answer (4)
Heavy water is weaker acid than normal water. Kw of D2O < Kw of H2O.
Comprehension-III
1. Answer (1) At no. is same for all.
2. Answer (3)
Bond-strength and area overlapping.
3. Answer (1)
Section-D
Q.No. Solutions 1. Answer (1) 2 2 4 SO H 2 2 4 H O MnSO H O O KMnO 24 2. Answer (2)O—O bond in O2F2 is shorter than that of H2O2. H2O2 is a polar covalent molecule.
3. Answer (1) H O 2HSO 2H H SO — O — O — S HO 4 mole 12 2 Hydrolysis 3 mole 1 3 4. Answer (4) Zn + 2NaOH Na2ZnO2 + H2
Zn(OH)2 is amphoteric in nature
5. Answer (2)
2Al + 2NaOH 2NaAlO2 + H2
6. Answer (1)
Statement-2 explains statement-1
7. Answer (4) In thermal decomposition 2 2 2 2 1 H O H O O 2 , it is “1”
Q.No. Solutions
1. Answer : A(p, q, r, s), B(p, q, s), C(p, r), D(q, s)
(A) H2O2 act as oxidizing agent, reducing agent, bleaching agent and acidic in nature
(B) HNO2 act as both oxidising agent, reducing agent and acidic in nature.
(C) O3 is an oxidising and bleaching agent
(D) H2S reducing agent and acidic in nature
2. Answer : A(p, r, s), B(p, r, s), C(p), D(p, r, s)
(A) sp3 hybridisation is present in H2O, H2O2, B2H6 and NH3. H2O, H2O2 and NH3 can form hydrogen
bonding. H2O, H2O2 and NH3 also have lone pair in their structure.
3. Answer A(p, q, s, t), B(p, r, s, t), C(p, s, t), D(p, s, t)
Structures of H2O2 are same but with different bond lengths and bond angles. All are like half open
book structure. H2O is bent molecule.
4. Answer A(r, s, t), B(p, s, t), C(p, s, t), D(q, s) Ca(HCO3)2 + Na2CO3 CaCO3 + 2NaHCO3
CaSO4 + Na2CO3 CaCO3 + Na2SO4 (NaPO3)6 is calgon 5. Answer A(t), B(q, r), C(p), D(s) Self explanatory.
Section-F
Q.No. Solutions 1. Answer (4)Each molecules is surrounded by 4 water.
2. Answer (2) H2O2 O2 + 2e–
3. Answer (5)
Q.No. Solutions
1. Answer (1)
Dielectric constant of H2O2 is greater than H2O. Boiling point and freezing point of D2O are greater & H2
requires less energy.
2. Answer (1)
Tritium is radioactive. Solubility of NaCl is more in H2O due to high dielectric constant. pH value of H2O
decreases by increasing temperature.
3. Answer (1) Factual
Section-H
Q.No. Solutions 1. Answer (3) Bond length 1 bond strength 2. Answer (3, 4)For same atom, hydration enthalpies of cation anion
3. Answer (3) 2 2 3 N 3D 2ND 4. Answer (4) Factual 5. Answer (2) Bond strength 1 bond length 6. Answer (4)
7. BaH2 + 2H2O Ba(OH)2 + 2H2
Moles of hydrogen produced =
0821 . 0 1 293 975 . 0 36 . 4 = 0.1768 mole
2 mole of hydrogen is produced from = 1 mole of BaH2
1 mole of hydrogen is produced = 2 1
mole of BaH2
0.176 mole of hydrogen is produced = 0.176
21 = 0.088 moles of BaH2 wt. of BaH2 require : 0.088 × 139 = 12.232 g
8. Na impart golden yellow colour to Bunsen burner flame. 2Na + 2H2O B' '2 C H 2NaOH B2 2 2 C D H ZnO Na NaOH 2 Zn Zn + H2SO4 ZnSO4 + H2 9. X + H2 C º 200 XH2 XH2 X + H2 1 gm of X can produce = 559 ml of H2 X + Cl2 XCl2
One equivalent of hydrogen is produced by = 11200
5591 = 20 gm 63.89 gm chlorine with metal = 36.11 gm
1 gm combine with metal = 89 . 63 11 . 36 35.5 gm combine with 35.5 89 . 63 11 . 36 = 20 g n factor: 2 So atomic wt. = 40 So metal is Ca X = Ca Y = CaH2 Z = CaCl2
10. 2K4[Fe(CN)6] + H2O2 + H2SO4 2K3[Fe(CN)6] + H2SO4 + H2O
2K3[Fe(CN)6] + H2O2 + KOH 3K4[Fe(CN)6] + 2H2O + O2
11. The reaction between hydrazine and H2O2 is highly exothermic and is accompanied by large increase
in the volume of the products and hence, this mixture is used as a rocket propellant NH2 – NH2(l) + 2H2O2(l) Cu(II) N2(g) + 4H2O(g)
12. Equivalent of I2 liberated = equivalent of hypo used = equivalent of H2O2
So, N(HO ) 1000 25 .3 0 1000 20 2 2 N(H2O2) = 20 0.3 2.4 10 4 1000 1000 25 = 0.24 N
So, volume strength = 0.24 × 5.6 = 1.34 volume
13. (i) LiH will give more amount of H2
Due to low molecular weight, in equal amount it has high no. of moles. 2LiH + H2O LiOH + H2
(ii) CaH2 + 2H2O Ca(OH)2 + 2H2
Moles of H2 produced : 0821 . 1 298 100 150 = 6.13×102 2 mole of H2 is produced by = 42 g 6.13 × 102 mole of H 2 will be produced by kg 2 1000 10 13 . 6 42 2 = 12.873 kg 14. H2O2 ionise as H2O2 H+ + HO2– pH = –log(H+) = 5.9 H+ = 10–5.9 Xionic = 10–5.9 × 10–5.9 = 10–11.8 = 1.58 × 10–12 15. 5
