A dilute aqueous solution of Na₂ SO₄ is electrolysed using platinum electrodes. The products at the anode and cathode are

1

(a)

O₂ , H₂

(b)

SO₂ , Na

(c)

O₂ , Na

(d)

S₂ O₈^2- , H₂

Unit of ionic mobility is

1

(a)

m² sec^-1 volt^-1

(b)

m s^-1

(c)

m sec^-1 volt

(d)

m sec^-1 volt^-1

Electrode potential of any electrode depends on :

1

(a)

nature of the metal

(b)

temperature of the solution

(c)

molarity of the solution

(d)

all of these

Standard electrode potential of three metals X, Y and Z are -1.2 V, + 0.5 v and - 3.0 V respectively. The reducing power of these metals will be

1

(a)

X > Y > Z

(b)

Y > Z > X

(c)

Y > X > Z

(d)

Z > X > Y

A gas X at 1 atm is bubbled through a solution containing a mixture of 1M Y^- and 1M Z^- ions at 25°C . If the reduction potential of Z > Y > X, then

1

(a)

Y will oxidize X but not Z

(b)

Y will oxidize both X and Z

(c)

Y will oxidize Z but not X

(d)

Y will reduce both X and Z

If Zn²⁺ / Zn electrode is diluted 100 times, then the change in emf is

1

(a)

increase of 59 mV

(b)

decrease of 59 mV

(c)

increase of 29.5 mV

(d)

decrease of 29.5 mV

What will be the e.m.f of the given cell ? Pt | H₂ (P₁) | H⁺ (aq) | H₂ (P₂) | Pt

1

(a)

\(\frac { RT }{ F } In\frac { { P }_{ 1 } }{ { P }_{ 2 } } \)

(b)

\(\frac { RT }{ 2F } In\frac { { P }_{ 1 } }{ { P }_{ 2 } } \)

(c)

\(\frac { RT }{ F } In\frac { { P }_{ 2 } }{ { P }_{ 1} } \)

(d)

none of these

For the reduction of silver ions with copper metal, the standard cell potential was found to be + 0.46 V at 25°C. The value of standard Gibbs energy, \({ \Delta G }^{ ° }\) will be (F = 96500 C mol^-1)

1

(a)

- 98.0 kJ

(b)

- 89.0 kJ

(c)

- 89.0 J

(d)

- 44.5 kJ

Among the following cells
Leclanche cell (I), Nickel-cadmium cell (II), Lead storage battery (III), Mercury cell (IV), primary cells are

1

(a)

I and II

(b)

I and III

(c)

II and III

(d)

I and IV

Which one of the following statement is always true about the spontaneous cell reaction in a galvanic cell?

1

(a)

\({ E_{ cell } }^{ ° }>0,{ \Delta G }^{ ° }>0,Q>{ K }_{ c }\) 

(b)

\({ E_{ cell } }^{ ° }<0,{ \Delta G }^{ ° }<0,Q<{ K }_{ c }\)

(c)

\({ E_{ cell } }^{ ° }>0,{ \Delta G }^{ ° }<0,Q<{ K }_{ c }\)

(d)

\({ E_{ cell } }^{ ° }>0,{ \Delta G }^{ ° }<0,Q>{ K }_{ c }\)

Can absolute electrode potential of an electrode be measured?

1

(a)

No, because electrode potential of a single electron cannot be mentioned.

Can E^o_cell or \({ \triangle }_{ r }{ G }^{ o }\) for a cell reaction ever be equal to zero?

1

(a)

No, but E_cell or \({ \triangle }_{ r }{ G }^{ o }\) of reaction can be zero at equilibrium.

Under what condition os E_cell = 0 or \({ \triangle }_{ r }{ G }\) = 0?

1

(a)

When the cell reaction reaches equilibrium.

What does the negative sign in expression E^o_Zn²⁺/Zn =-0.76 V mean?

1

(a)

It means zinc is more reactive than hydrogen, therefore, acts as anode when coupled to S.H.E and gets oxidised to Zn²⁺ (aq) and H⁺ will get reduced to H₂ (g).