How many cc of oxygen will be liberated by 2 A current flowing for 3 min 13 s through acidulated water?
11.2 cc
33.6 cc
44.8 cc
22.4 cc
D.
22.4 cc
When acidulated water is electrolysed, the following reactions will take place at anode and cathode.
At cathode,
2H+ (aq) + 2e- → H2 (g)
At anode,
2H2O (l) → O2(g) + 4H+ (aq) + 4e-
The net reaction is
2H2 (g) + O2 (g)
From the reaction of the anode, it is clear that 4F liberates oxygen = 22400 cc
(3 × 60 / 13) × 2C electricity will liberate O2.
=
= 22.4 cc
Consider the following statements.
(1) Fuel cells are voltaic cell which convert electrical energy of fuel into chemical energy.
(2) Fuel cells are galvanic cells which convert chemical energy of fuel into electrical energy.
(3) The efficiency of H2-O2 fuel cell is approximately 25%.
(4) Fuel cells do not cause pollution problem.
Among these, the correct statements are
(2) and (3) only
(1) and (4) only
(2) and (4) only
(2), (3) and (4) only
The standard reduction potential E° for half-reactions are
Zn → Zn2+ + 2e- ; E° = +0.76 V
Fe → Fe2+ + 2e- ; E° = +0.41 V
The EMF of the cell reaction
Fe2+ + Zn → Zn2+ + Fe is
+1.28 V
-1.28 V
+0.35 V
-0.35 V
Certain electric current for half an hour can collect 11.2 L of hydrogen at NTP. Same current when passed through an electrolytic solution for one hour, can deposite how much silver?
216g
108 g
47 g
60 g
Aluminium is extracted by the electrolysis of
alumina
bauxite
molten cryolite
alumina mixed with molten cryolite
Saturated solution of KNO3 is used to make salt bridge because
KNO3 is highly soluble in water
velocity of K+ is greater than that of NO
Velocity of NO 1s greater than that of K+
velocity of K+ and NO are almost equal
One Faraday of charge passes through solution of AgNO3 and CuSO4 connected in series and the concentration of two solutions being in the ratio 1 : 2. The ratio of amount of Ag and Cu deposited on Pt electrode is
1079.6354
54.3177
1079.3177
54.6354
On passing 0.5 Faraday of electricity through NaCl, the amount of Cl deposited on cathode is
35.5 g
17.75 g
71 g
142 g