The correct structure of tribromo octoxide is:

1.
2.
3.
4.

Disproportionation reactions are:

1. (a) and (d) only

2. (a) and (b) only

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

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

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

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. ${\mathrm{HNO}}_3,\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}{\mathrm{N}}_2$

3. ${\mathrm{HNO}}_3,\hspace{0.17em}{\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{N}}_2$

4. ${\mathrm{NH}}_4\mathrm{Cl},\hspace{0.17em}{\mathrm{N}}_2,\hspace{0.17em}\mathrm{NO},\hspace{0.17em}{\mathrm{HNO}}_3$

  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.