Specific conductance has the unit:

1. $oh{m}^{-1}<mspace\; width="1em"></mspace>c{m}^{-1}$                           

2. ohm.cm

3. $ohm<mspace\; width="1em"></mspace>c{m}^{-1}$                             

4. $oh{m}^{-1}.cm$

What is the value of ${\mathrm{pK}}_{\mathrm{b}}<mspace\; width="1em"></mspace>({\mathrm{CH}}_3{\mathrm{COO}}^{-}<mspace\; width="1em"></mspace>)$ if ${\mathrm{\lambda }}_{\mathrm{m}}^0=<mspace\; width="1em"></mspace>390<mspace\; width="1em"></mspace>\&<mspace\; width="1em"></mspace>{\mathrm{\lambda }}_{\mathrm{m}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>7.8$ for 0.04 of a $<mspace\; width="1em"></mspace>{\mathrm{CH}}_3\mathrm{COOH}$  at $25°\mathrm{C}$ ?

(A) 9.3                                               

(B) 9.2

(C) 4.7                                               

(D) 4.8

At $25°C$, the standard emf of cell having reactions involving two electron change is found to be 0.295 V. The equilibrium constant of the reaction is-

$\left(A\right)<mspace\; width="1em"></mspace>29.5<mspace\; width="1em"></mspace>\times <mspace\; width="1em"></mspace>{10}^{-2}$

$\left(B\right)<mspace\; width="1em"></mspace>10<mspace\; width="1em"></mspace>$

$\left(C\right)<mspace\; width="1em"></mspace>{10}^{10}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

$\left(D\right)<mspace\; width="1em"></mspace>29.5<mspace\; width="1em"></mspace>\times <mspace\; width="1em"></mspace>{10}^{10}$

The number of faradays required to produce one mole of water from a hydrogen-oxygen fuel cell containing aqueous alkali as an electrolyte is-

1. 1                               

2. 3

3. 2                               

4. 4

How much current is necessary to produce $H_2$ gas at the rate of 1 $c{m}^3$ per second under STP ?

(A) 4.305 amp                                           

(B) 17.22 amp

(C) 8.61 amp                                            

(D) 2.1525 amp.

A current of 0.250 A is passed through 400 ml of a 2.0 M solution of NaCl for 35 minutes. What will be the pH of the solution after the current is turned off ?

(A) 12.98                            

(B) 12.13

(C) 10.48                            

(D) 9.24

During discharge of a lead storage cell, the density of sulphuric acid in the cell-

1. Increases.                                     

2. Decreases.

3. Remains unchanged.                      

4. Initially increases but decreases subsequently.

The cell reaction for the given cell is spontaneous if- 

$Pt(H_2,P_1<mspace\; width="1em"></mspace>)<mspace\; width="1em"></mspace>H^{+}<mspace\; width="1em"></mspace>\left(1M\right)<mspace\; width="1em"></mspace>\left|\right|<mspace\; width="1em"></mspace>H^{+}<mspace\; width="1em"></mspace>\left(1M\right)<mspace\; width="1em"></mspace>|<mspace\; width="1em"></mspace>Pt(H_2,<mspace\; width="1em"></mspace>P_2<mspace\; width="1em"></mspace>)$

$\left(A\right)<mspace\; width="1em"></mspace>P_1<mspace\; width="1em"></mspace>><mspace\; width="1em"></mspace>P_2$

$\left(B\right)<mspace\; width="1em"></mspace>P_1<mspace\; width="1em"></mspace><<mspace\; width="1em"></mspace>P_2<mspace\; width="1em"></mspace>$

$\left(C\right)<mspace\; width="1em"></mspace>P_1<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>P_2$

$\left(D\right)<mspace\; width="1em"></mspace>P_2<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>1<mspace\; width="1em"></mspace>atm$

The standard electrode potentials (reduction) of Pt/Fe³⁺, Fe²⁺ and Pt/Sn⁴⁺, Sn²⁺ are + 0.77 V and + 0.15 V respectively at 25°C. The standard EMF of the reaction Sn⁴⁺ + 2Fe²⁺ → Sn²⁺ + 2Fe³⁺ is

(A) – 0.62 V                                        

(B) – 0.92 V

(C) + 0.31 V                                        

(D) + 0.85 V

Specific conductance of 0.01 M KCl solution is x $oh{m}^{-1}c{m}^{-1}$. When conductivity cell is filled with 0.01 M KCl the conductance observed is y $oh{m}^{-1}$. When the same cell is filled with 0.01 M$<mspace\; width="1em"></mspace>H_2<mspace\; width="1em"></mspace>S{O}_4$ the observed conductance was $z<mspace\; width="1em"></mspace>oh{m}^{-1}<mspace\; width="1em"></mspace>c{m}^{-1}.$ Hence specific conductance of 0.01 M $H_2<mspace\; width="1em"></mspace>S{O}_4$ is-

(a) xz                                                                

(b) z/xy

(c) xz/y                                                             

(d) xy/z