1
JEE Main 2020 (Online) 2nd September Morning Slot
Numerical
+4
-0
The Gibbs change (in J) for the given reaction at
[Cu2+] = [Sn2+] = 1 M and 298K is :

Cu(s) + Sn2+(aq.) $$\to$$ Cu2+(aq.) + Sn(s);

($$E_{S{n^{2 + }}|Sn}^0 = - 0.16\,V$$,
$$E_{C{u^{2 + }}|Cu}^0 = 0.34\,V$$)
Take F = 96500 C mol–1)
2
JEE Main 2020 (Online) 9th January Morning Slot
Numerical
+4
-0
108 g of silver (molar mass 108 g mol–1) is deposited at cathode from AgNO3(aq) solution by a certain quantity of electricity. The volume (in L) of oxygen gas produced at 273 K and 1 bar pressure from water by the same quantity of electricity is _______.
3
JEE Main 2020 (Online) 8th January Evening Slot
Numerical
+4
-0
For an electrochemical cell

Sn(s) | Sn2+ (aq,1M)||Pb2+ (aq,1M)|Pb(s)

the ratio $${{\left[ {S{n^{2 + }}} \right]} \over {\left[ {P{b^{2 + }}} \right]}}$$ when this cell attains equilibrium is _________.

(Given $$E_{S{n^{2 + }}|Sn}^0 = - 0.14V$$,

$$E_{P{b^{2 + }}|Pb}^0 = - 0.13V$$, $${{2.303RT} \over F} = 0.06$$)
4
JEE Main 2020 (Online) 8th January Morning Slot
Numerical
+4
-0
What would be the electrode potential for the given half cell reaction at pH = 5? ______.

2H2O $$\to$$ O2 + 4H$$\oplus$$ + 4e ; $$E_{red}^0$$ = 1.23 V

(R = 8.314 J mol–1 K–1 ; Temp = 298 k;

oxygen under std. atm. pressure of 1 bar)