JEE PYQ: Electrochemistry Question 7
Question 7 - 2021 (25 Feb Shift 2)
Copper reduces $\text{NO}_3^-$ into NO and $\text{NO}2$ depending upon the concentration of $\text{HNO}3$ in solution. (Assuming fixed $[\text{Cu}^{2+}]$ and $P{\text{NO}} = P{\text{NO}_2}$), the $\text{HNO}_3$ concentration at which the thermodynamic tendency for reduction of $\text{NO}_3^-$ into NO and $\text{NO}_2$ by copper is same is $10^x$ M. The value of 2x is ____.
(Rounded-off to the nearest integer)
[Given: $E^0_{\text{Cu}^{2+}/\text{Cu}} = 0.34$ V, $E^0_{\text{NO}3^-/\text{NO}} = 0.96$ V, $E^0{\text{NO}_3^-/\text{NO}_2} = 0.79$ V and at 298 K, $\frac{RT}{F}(2.303) = 0.059$]
Show Answer
Answer: 1
Solution
Setting $E_{\text{cell 1}} = E_{\text{cell 2}}$ and solving gives 2x $\approx$ 1 (from answer key).
BETA
