Read the following statements (S) and Explanation (E). Choose the correct answers from the codes (1), (2), (3) and (4):

S : ${\mathrm{H}}_3{\mathrm{BO}}_3$ is monobasic Lewis acid but salt ${\mathrm{Na}}_3{\mathrm{BO}}_3$ exist.

E : ${\mathrm{H}}_3{\mathrm{BO}}_3$ reacts with $\mathrm{NaOH}$ to give ${\mathrm{Na}}_3{\mathrm{BO}}_3$.

1.  S is correct but E is wrong
2.  S is wrong but E is correct
3.  Both S and E are correct and E is correct explanation of S
4.  Both S and E are correct but E is not correct explanation of S

Disproportionation reactions are:

(a) $2{\mathrm{Cu}}^{+}$ $\to$ ${\mathrm{Cu}}^{2+}+{\mathrm{Cu}}^0$

(b) $3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}$ $\to$ $2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

(c) $2{\mathrm{KMnO}}_4$ $\stackrel{∆}{\to }$ ${\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{MnO}}_2+{\mathrm{O}}_2$

(d) $2{\mathrm{MnO}}_4^{-}+3{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O}$ $\to$ $5{\mathrm{MnO}}_2+4{\mathrm{H}}^{\oplus }$

1. (a) and (d) only

2. (a) and (b) only

3. (a), (b) and (c)

4. (a), (c) and (d)

The number of moles of KMnO₄ that will be needed to react with one mole of sulphite ion in an acidic solution is:

Number of moles of \(MnO^-_4\) required to oxidise one mole of ferrous oxalate completely in an acidic medium will be:

 ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{4-}\to {\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{3-}+{\mathrm{e}}^{-};$ ${\mathrm{E}}^{\mathrm{o}}=-0.35$ $\mathrm{V}$
${\mathrm{Fe}}^{2+}\to {\mathrm{Fe}}^{3+}+{\mathrm{e}}^{-};$ ${\mathrm{E}}^{\mathrm{o}}=-0.77$ $\mathrm{V}$
The strongest oxidizing agent in the above equation is:

1. ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{4-}$

2. ${\mathrm{Fe}}^{2+}$

3. ${\mathrm{Fe}}^{3+}$

4. ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{3-}$

The change in oxidation number of chlorine when Cl₂ gas reacts with hot and concentrated sodium hydroxide solution is:

1. Zero to +1 and Zero to -5

2. Zero to -1 and Zero to +5

3. Zero to -1 and Zero to +3

4. Zero to +1 and Zero to -3

For the redox reaction,
 a${\mathrm{MnO}}_4^{-}+{\mathrm{bC}}_2{\mathrm{O}}_4^{2-}+{\mathrm{cH}}^{+}\to {\mathrm{dMn}}^{2+}+{\mathrm{eCO}}_2+{\mathrm{fH}}_2\mathrm{O}$
the correct stoichiometric coefficients of the reactants a, b, and c respectively for the balanced equation are: 

1. 16, 5, 2
2. 2, 5, 16
3. 2, 16, 5
4. 5, 16, 2

The correct order of N-compounds in its decreasing order of oxidation states is :

1. ${\mathrm{HNO}}_3,$ $\mathrm{NO},$ ${\mathrm{N}}_2,$ ${\mathrm{NH}}_4\mathrm{Cl}$

2. ${\mathrm{HNO}}_3, \mathrm{NO}, {\mathrm{NH}}_4\mathrm{Cl}, {\mathrm{N}}_2$

3. ${\mathrm{HNO}}_3, {\mathrm{NH}}_4\mathrm{Cl}, \mathrm{NO}, {\mathrm{N}}_2$

4. ${\mathrm{NH}}_4\mathrm{Cl}, {\mathrm{N}}_2, \mathrm{NO}, {\mathrm{HNO}}_3$

  P₄ + NaOH → PH₃ + NaH₂PO₂

The correct statement among the following is -

1. P is oxidized only.

2. P is reduced only.

3. P is oxidized as well as reduced.

4. Na is reduced.

The oxidation number of Ba in barium peroxide is :

1. +6

2. +2

3. 1

4. +4