1
JEE Main 2018 (Offline)
+4
-1
How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen released can completely burn 27.66 g of diborane?
(Atomic weight of B = 10.8 u)
A
1.6 hours
B
6.4 hours
C
0.8 hours
D
3.2 hours
2
JEE Main 2018 (Online) 15th April Morning Slot
+4
-1
When an electric currents passed through acidified water, 112 mL of hydrogen gas at N.T.P. was collected at the cathode in 965 seconds. The current passed, in ampere, is :
A
1.0
B
0.5
C
0.1
D
2.0
3
JEE Main 2017 (Online) 9th April Morning Slot
+4
-1
To find the standard potential of M3+/M electrode,the following cell is constituted : Pt/M/M3+(0.001 mol L−1 )/Ag+(0.01 mol L−1 )/Ag

The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction M3+ + 3e$$\to$$ M at 298 K will be :

(Given $$E_{A{g^ + }\,/\,Ag}^ -$$ at 298 K = 0.80 Volt)
A
0.38 Volt
B
0.32 Volt
C
1.28 Volt
D
0.66 Volt
4
JEE Main 2017 (Online) 8th April Morning Slot
+4
-1
What is the standard reduction potential (Eo) for Fe3+ $$\to$$ Fe ?
Given that :
Fe2+ + 2e$$-$$ $$\to$$ Fe; $$E_{F{e^{2 + }}/Fe}^o$$ = $$-$$0.47 V
Fe3+ + e$$-$$ $$\to$$ Fe2+; $$E_{F{e^{3 + }}/F{e^{2 + }}}^o$$ = +0.77 V
A
$$-$$ 0.057 V
B
+ 0.057 V
C
+ 0.30 V
D
$$-$$ 0.30 V
EXAM MAP
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