List of top Chemistry Questions on Electrochemical Cells and Gibbs Free Energy asked in JEE Main

One half cell in a voltaic cell is constructed by dipping silver rod in $AgNO_3$ solution of unknown concentration, other half cell is Zn rod dipped in 1 molar solution of $ZnSO_4$.
A voltage of 1.60 V is measured at 298 K for this cell. What is the concentration of $Ag^+$ ions used in terms of $\log x$ ($x = [Ag^+]$)?
$E^\ominus_{Zn^{2+}/Zn} = -0.76 V$, $E^\ominus_{Ag^+/Ag} = +0.80 V$, $\frac{2.303 RT}{F} = 0.059 V$

Consider the reaction $ aX \rightarrow bY $, for which the rate constant at 30°C is $ 1 \times 10^{-3} \, \text{mol}^{-1} \, \text{L} \, \text{s}^{-1} $. Which of the following statements are true?}

(A) When concentration of $ X $ is increased to four times, the rate of reaction becomes 16 times.
(B) The reaction is a second order reaction.
(C) The half-life period is independent of the concentration of $ X $.
(D) Decomposition of $ \text{N}_2\text{O}_5 $ is an example of the above reaction.
(E)
is valid for the reaction

Choose the correct answer from the options given below:

An electrochemical cell is constructed using half cells in the direction of spontaneous change} \[ Fe(OH)_2(s) + 2e^- \rightarrow Fe(s) + 2OH^- (aq) \qquad E^\circ = -0.88\,V \] \[ AgBr(s) + e^- \rightarrow Ag(s) + Br^- (aq) \qquad E^\circ = +0.07\,V \] Which of the following option is correct?

For a general redox reaction} \[ \text{Anode: } \text{Red}_1 \rightarrow \text{Ox}_1^{n_1+} + n_1e^- \] \[ \text{Cathode: } \text{Ox}_2 + n_2e^- \rightarrow \text{Red}_2^{n_2-} \] Which of the following statement is incorrect?

Given below are two statements:
Statement I: When $E_a = 12.6$ kcal/mol, the room temperature rate constant is doubled by a 10 °C increase in temperature (298 K to 308 K).
Statement II: For a first order reactions $A \to B$, [the graph of rate vs [A] is a straight line through origin].

Consider the following cell: $ \text{Pt}(s) \, \text{H}_2 (1 \, \text{atm}) | \text{H}^+ (1 \, \text{M}) | \text{Cr}_2\text{O}_7^{2-}, \, \text{Cr}^{3+} | \text{H}^+ (1 \, \text{M}) | \text{Pt}(s) $
Given: $ E^\circ_{\text{Cr}_2\text{O}_7^{2-}/\text{Cr}^{3+}} = 1.33 \, \text{V}, \quad \left[ \text{Cr}^{3+} \right]^2 / \left[ \text{Cr}_2\text{O}_7^{2-} \right] = 10^{-7} $
At equilibrium: $ \left[ \text{Cr}^{3+} \right]^2 / \left[ \text{Cr}_2\text{O}_7^{2-} \right] = 10^{-7} $
Objective: $ \text{Determine the pH at the cathode where } E_{\text{cell}} = 0. $

Standard electrode potentials for a few half-cells are mentioned below: