The oxidation state of two S-atoms in ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ is:

1. +2 and +4

2. +3 and -2

3. +4 and -2

4. +6 and -2

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

${\mathrm{E}}^{\mathrm{\Theta }}<mspace\; width="1em"></mspace>\mathrm{values}:<mspace\; width="1em"></mspace>{\mathrm{Br}}_2/{\mathrm{Br}}^{-}=+1.90$
${\mathrm{Ag}}^{+}/\mathrm{Ag}\left(\mathrm{s}\right)=+0.80$
${\mathrm{Cu}}^{2+}/\mathrm{Cu}\left(\mathrm{s}\right)=+0.34;<mspace\; width="1em"></mspace>$
${\mathrm{I}}_2\left(\mathrm{s}\right)/{\mathrm{I}}^{-}=+0.54$

When zinc rod is directly placed in copper sulphate solution:

1. The blue colour of the solution starts intensifying.

2. The solution remains electrically neutral.

3. The temperature of the solution falls.

4. The weight of the zinc rod starts increasing.

From the following, identify the reaction having the top position in the EMF series (standard reduction potential) according to their electrode potential at 298 K.

The set of metals/metal ion that can show disproportionation reaction is:

The correct statement about the electrolysis of an aqueous solution of ${\mathrm{AgNO}}_3$ with Ag electrode is:

Consider the given reaction:
\(\mathrm{Al}+\mathrm{Fe}_3 \mathrm{O}_4 \rightarrow \mathrm{Al}_2 \mathrm{O}_3+\mathrm{Fe}\)

What is the total number of electrons transferred in the given reaction?
1. 6
2. 8
3. 8/3
4. 24

The sum of the coefficients of the reactants in the following reaction is :

$....{\mathrm{CS}}_2+.....{\mathrm{Cl}}_2\to {\mathrm{CCl}}_4+....{\mathrm{S}}_2{\mathrm{Cl}}_2$

1. 5

2. 3

3. 6

4. 4

What is the number of moles of K₂Cr₂O₇ required to oxidise 1 mole of ferrous oxalate in an acidic medium?