The element that does not show a disproportionation tendency is/are:

Which of the following is not an example of redox reaction?

1. $\mathrm{CuO}+{\mathrm{H}}_2\to \mathrm{Cu}+{\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{Fe}}_2{\mathrm{O}}_3+3\mathrm{CO}\to 2\mathrm{Fe}+3{\mathrm{CO}}_2$

3. $2\mathrm{K}+{\mathrm{F}}_2\to 2\mathrm{KF}$

4. ${\mathrm{BaCl}}_2+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{BaSO}}_4+2\mathrm{HCl}$

Using the standard electrode potentials of the redox couples given below, which of the following is the strongest oxidizing agent?

${\mathrm{E}}^{⊝} \mathrm{values}: {\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}=+0.\mathrm{77\; V}$ 
${\mathrm{I}}_2\left(\mathrm{s}\right)/{\mathrm{I}}^{-}=+0.54 V$
${\mathrm{Cu}}^{2+}/\mathrm{Cu}=+0.\mathrm{34\; V}$
${\mathrm{Ag}}^{+}/\mathrm{Ag}=0.\mathrm{80\; V}$

1. Fe³⁺
2. I₂(s)
3. Cu²⁺
4. Ag⁺

${\mathrm{E}}^{\Theta }$ values of some redox couples are given below. On the basis of these values choose the correct option.

${\mathrm{E}}^{\mathrm{\Theta }} \mathrm{values}: {\mathrm{Br}}_2/{\mathrm{Br}}^{-}=+1.90$
${\mathrm{Ag}}^{+}/\mathrm{Ag}\left(\mathrm{s}\right)=+0.80$
${\mathrm{Cu}}^{2+}/\mathrm{Cu}\left(\mathrm{s}\right)=+0.34;$
${\mathrm{I}}_2\left(\mathrm{s}\right)/{\mathrm{I}}^{-}=+0.54$

Using the standard electrode potential, find out the pair between which redox reaction is not feasible.

${\mathrm{E}}^{⊝} \mathrm{values}: {\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}=+0.77; {\mathrm{I}}_2/{\mathrm{I}}^{-}=+0.54;$
${\mathrm{Cu}}^{2+}/\mathrm{Cu}=+0.34; {\mathrm{Ag}}^{+}/\mathrm{Ag}=+0.80 \mathrm{V}$

1. Fe³⁺ and I^-

2. Ag⁺ and Cu

3. Fe³⁺ and Cu

4. Ag and Fe³⁺

In the reactions given below, thiosulphate reacts differently with iodine than with bromine.

$2{\mathrm{S}}_2{\mathrm{O}}_3^{2-}+{\mathrm{I}}_2\to {\mathrm{S}}_4{\mathrm{O}}_6^{2-}+2{\mathrm{I}}^{-}$

${\mathrm{S}}_2{\mathrm{O}}_3^{2-}+2{\mathrm{Br}}_2+5{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{SO}}_4^{2-}+2{\mathrm{Br}}^{-}+10{\mathrm{H}}^{+}$

Choose the statements among the following that best describe the above dual behaviour of thiosulphate.

Which of the following statement regarding the rules to calculate the oxidation number is incorrect?

In which of the following compounds, an element exhibits two different oxidation state?