PYQ Vault
EbooksTutor

Number of metals a given oxidant can oxidise, from standard reduction potentials

This type of question, asked 2 times: 6 Apr 2023, 9 Apr 2024. All 2 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    6 Apr 2023

    144
    The standard reduction potential at 298 K298\text{ }K for the following half cells are given below:
    NO3−+4H++3e−→NO(g)+2H2O    E0=0.97 VNO_{3}^{-}+ 4H^{+}+ 3e^{-}\rightarrow NO\left( g \right)+ 2H_{2}O\ \ \ \ E^{0}= 0.97\text{ }V
     V2+(aq)+2e−→V             E0=−1.19 VFe3+(aq)+3e−→Fe             E0=−0.04 VAg+(aq)+e−→Ag(s)             E0=0.80 VAu3+(aq)+3e−→Au(s)             E0=1.40 V\begin{matrix} & \\ {\text{ }V}^{2 +}(aq) + 2e^{-}\rightarrow V & \ \ \ \ \ \ \ \ \ \ \ \ \ E^{0}= - 1.19\text{ }V \\ Fe^{3 +}(aq) + 3e^{-}\rightarrow Fe & \ \ \ \ \ \ \ \ \ \ \ \ \ E^{0}= - 0.04\text{ }V \\ Ag^{+}(aq) +e^{-}\rightarrow Ag(s) & \ \ \ \ \ \ \ \ \ \ \ \ \ E^{0}= 0.80\text{ }V \\ Au^{3 +}(aq) + 3e^{-}\rightarrow Au(s) & \ \ \ \ \ \ \ \ \ \ \ \ \ E^{0}= 1.40\text{ }V \end{matrix}
    The number of metal(s) which will be oxidized by NO3−NO_{3}^{-}in aqueous solution is___

  2. Question 2

    9 Apr 2024

    54
    The standard reduction potentials at 298 K298\text{ }K for the following half cells are given below:
    Cr2O7 2−+14H++6e−→2Cr3++7H2O,E∘=1.33 VCr_{2}O_{7}\ ^{2 -}+ 14H^{+}+ 6e^{-}\rightarrow 2Cr^{3 +}+ 7H_{2}O,E^{\circ}= 1.33\text{ }V
    Fe3+(aq)+3e−→Fe E∘=−0.04 VFe^{3 +}(aq) + 3e^{-}\rightarrow Fe\ E^{\circ}= - 0.04\text{ }V
    Ni2+(aq)+2e−→Ni E∘=−0.25 VNi^{2 +}(aq) + 2e^{-}\rightarrow Ni\ E^{\circ}= - 0.25\text{ }V
    Ag+(aq)+e−→Ag E∘=0.80 VAg^{+}(aq) +e^{-}\rightarrow Ag\ E^{\circ}= 0.80\text{ }V
    Au3+(aq)+3e−→Au E∘=1.40 VAu^{3 +}(aq) + 3e^{-}\rightarrow Au\ E^{\circ}= 1.40\text{ }V
    Consider the given electrochemical reactions, The number of metal(s) which will be oxidized by Cr2O72−Cr_{2}O_{7}^{2 -}, in aqueous solution is ____