Find the magnitude of the emf of the following concentration cell at 25°C:

Pt(H₂) | 0.1 M acetic acid + 0.1 M sodium acetate || 0.1 M formic acid + 0.1 M sodium formate | Pt(H₂)

Given:

Kₐ (Acetic acid) = 1.8 × 10⁻⁵
Kₐ (Formic acid) = 2.1 × 10⁻⁴

1.  0.0315 volt

2.  0.0629 volt

3.  0.0455 volt

4.  0.0545 volt

If the E°_cell for a given reaction has a negative value then which of the following gives the

correct relationships for the values of $∆$G° and K_eq?

1. $∆$G° < 0;K_eq > 1

2. $∆$G° < 0; K_eq < 1

3. $∆$G°> 0; K_eq < 1

4. $∆$G° > 0; K_eq > 1

 $F_2$ gas can’t be obtained by the electrolysis of any $F^{-1}$salt because-

1. Fluorine is the strongest reducing agent

2. Fluorine is the strongest oxidising agent.

3. Fluorine easily combine with atmospheric $O_2$

4. All

A device that converts energy of the combustion of fuels like hydrogen and methane, directly

into electrical energy is known as:

1. Fuel cell

2. Electrolytic cell

3. Dynamo

4. Ni-Cd cell

What will be the quantity of iron deposited by ferrous and ferric ion by 1F (Fe = 56) :

1.  14g, 9.3 g                                          

2.  28g, 18.6 g

3.  56g, 37.2g                                         

4.  None of the above

Specific conductance has the unit:
1. \(\mathrm{ohm}^{-1} \mathrm{~cm}^{-1}\)
2.\(\text { ohm.cm }\)
3.\(\text { ohm } \mathrm{cm}^{-1}\)
4. \(\mathrm{ohm}^{-1} . \mathrm{cm}\)

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

A certain current liberates 0.504 g of hydrogen in 2 hours. How many gram of copper can be liberated by the same current flowing for the same time in aqueous $CuS{O}_4$ solution :

(1) 12.7                                                             

(2) 16

(3) 31.8                                                             

(4) 63.5

The metal that cannot be produced on reduction of its oxide by aluminium is :

(1) K                                                        

(2) Mn

(3) Cr                                                      

(4) Fe

 ${\mathrm{E}}^0<mspace\; width="1em"></mspace>\mathrm{for}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{reaction}<mspace\; width="1em"></mspace>$
$\mathrm{Fe}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{Zn}}^{2+}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>\mathrm{Zn}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{Fe}}^{2+}<mspace\; width="1em"></mspace>\mathrm{is}<mspace\; width="1em"></mspace>–<mspace\; width="1em"></mspace>0.35<mspace\; width="1em"></mspace>\mathrm{V}.$
The   given   cell   reaction   is: 

1. Feasible  

2. Not feasible

3. In equilibrium 

4. None of the above