Chemistry - Redox Reactions Question with Solution | TestHub

Question Explanation: Find matches the following for per mole ${\mathrm{Br}}_2$.

Concept: This question is based on balancing of redox reaction.

Solution:

The balanced chemical equation for the reaction of Br₂ with hot KOH solution is:

$$3B{r}_2+6KOH\to 5KBr+KBr{O}_3+3H_{2}O$$

Dividing the entire equation by 3 to find the number of moles of each substance per mole of Br₂:

$$B{r}_2+2KOH\to \frac{5}{3}KBr+\frac{1}{3}KBr{O}_3+H_{2}O$$

Now, matching the compounds in Column I with the stoichiometric coefficients (moles per mole of Br₂) from Column II:

(P) KOH → Coefficient is 2, which is value (1).

(Q) KBr → Coefficient is $\frac{5}{3}$, which is value (2).

(R) KBrO₃ → Coefficient is $\frac{1}{3}$, which is value (3).

(S) Br₂ → Coefficient is 1, which is value (4).

The correct matching is P → 1; Q → 2; R → 3; S → 4.

Final Answer: Option (B)