1
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
In a first-order reaction A $$ \to $$ B, if k is rate constant and initial concentration of the reactant A is 0.5 M, then the half-life is
A
$${{\log 2} \over k}$$
B
$${{\log 2} \over {k\sqrt {0.5} }}$$
C
$${{\ln 2} \over k}$$
D
$${{0.693} \over {0.5k}}$$
2
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
The efficiency of a fuel cell is given by
A
$$\Delta $$G/$$\Delta $$S
B
$$\Delta $$G/$$\Delta $$H
C
$$\Delta $$S/$$\Delta $$G
D
$$\Delta $$H/$$\Delta $$G
3
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
The equilibrium constant of the reaction:
Cu(s) + 2Ag+(aq) $$ \to $$ Cu2+(aq) + 2Ag(s);
Eo = 0.46 V at 298 K is
A
2.0 $$ \times $$ 1010
B
4.0 $$ \times $$ 1010
C
4.0 $$ \times $$ 1015
D
2.4 $$ \times $$ 1010
4
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
The reaction of hydrogen and iodine monochloride is given as :
H2(g) + 2ICl(g) $$ \to $$ 2HCl(g) + I2(g)
This reaction is of first order with respect to H2(g) and ICl(g),
following mechanisms were proposed.

Mechanism A :
     H2(g) + 2ICl(g) $$ \to $$ 2HCl(g) + I2(g)
Mechanism B :
     H2(g) + ICl(g) $$ \to $$ HCl(g) + HI(g) ; slow
     HI(g) + ICl(g) $$ \to $$ HCl(g) + I2(g) ; fast

Which of the above mechanism(s) can be consistent with the given information about the reaction?
A
A and B both
B
Neither A nor B
C
A only
D
B only