Assertion : Silver nitrate solution becomes bluish when copper rod is placed in it.

Reason : Copper is more electropositive than silver.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion : : Sodium reacts with water at room temperature, whereas magnesium decomposes only hot water.

Reason : Sodium is more electropositive than magnesium.

Assertion : Fluorine cannot be prepared from fluorides by chemical oxidation.

Reason : Fluorine is the strongest oxidizing agent due to its highly positive standard potential.

Calculate the EMF of the cell at 298 K $Pt | H_2 (1atm) | NaOH \left(xM\right), NaCl \left(xM\right) | AgCl (s) | Ag$ ${E^{°}}_{C{l}^{-}/AgCl/Ag}=+0.222 V$

(1) – 0.604 V                                                  

(2) – 0.04 V

(3) 1.048 V                                  

(4) emf depends on x and cannot be determined unless value of x is given

In acidic medium $Mn{O_4}^{-}$ is an oxidising agent. $Mn{O_4}^{-} + 8H^{+} + 5e^{-} \to M{n}^{2+} + 4H_{2}O. If H^{+}$ ion concentration is doubled, electrode potential of the half cell will : 

(1) Increase by 28.46 mV                             

(2) Decrease by 28.46 mV

(3) Increase by 14.23 mV                             

(4) Decrease by 142.30 mV

A current of 0.1A was passed for 2hr through a solution of cuprocyanide and 0.3745 g of

copper was deposited on the cathode. Calculate the current efficiency for the copper

deposition. (Cu – 63.5)

1. 79%                                 

2. 39.5%

3. 63.25%                             

4. 63.5%

Calculate the cell EMF in mV for $Pt | H_2 (1atm) | HCl (0.01 M) | AgCl(s) | Ag\left(s\right) at 298 K$ 

If $∆{G_r}^{°}$ values are at $25°C$ $-109.56\frac{kJ}{mol} for AgCl\left(s\right) \& –130.79\frac{kJ}{mol} for (H^{+}+ C{l}^{-}) \left(aq\right)$

(1) 456 mV                         

(2) 654 mV

(3) 546 mV                         

(4) None of these

An excess of granular zinc was added to 500 mL of 1M nickel nitrate till equilibrium was established. Find out the concentration of nickel at the equilibrium, if the standard electrode potential of $Z{n}^{2+} / Zn and N{i}^{2+}/Ni$ are – 0.75 and – 0.24 V, respectively.
(1) 5.56 x 10^-18 M
(2) 0.56 x 10^-18 M
(3) 2.16 x 10^-18 M
(4) 4.12 x 10^-18 M

A flashlight cell has the cathodic reaction $2Mn{O}_2 \left(s\right) + Z{n}^{+2}+ 2\text{'}{e}^{-}\to Zn M{n}_2{O}_4 \left(S\right)$

If the flashlight cell is to give out 4.825 mA, how long could it run if initially 8.7 g of the

limiting reagent $Mn{O}_2$ is present? [Mn = 55, O = 16]

(1) $2 \times {10}^{6}sec$                                         

(2) $4 \times {10}^{6}sec$

(3) $6\times {10}^{6}sec$                                          

(4) $8 \times {10}^{6}sec$

Following cell has EMF 0.7995 V 

$Pt | H_2 (1 atm) | HN{O}_3 \left(1M\right) \left|\right| AgN{O}_3 \left(1M\right) | Ag$. 

If we add enough KCl to the Ag cell so that the final $C{l}^{-}$is 1M. Now the measured emf of the cell is 0.222 V. The $K_{SP}$ of AgCl would be :

$\left(1\right) 1 \times {10}^{–9.8 }$

$\left(2\right) 1 \times {10}^{–19.6}$

$\left(3\right) 2 \times {10}^{–10}$

$\left(4\right) 2.64 \times {10}^{–14}$