NEET UG 2009 — Chemistry Physical Chemistry

2009mcqmedium

In the reaction, $\mathrm{BrO}_3^{-}$ (aq.) $+5 \mathrm{Br}^{-}$ (aq.) $+6 \mathrm{H}^{+}$ (aq.) $\rightarrow 3 \mathrm{Br}_2(\mathrm{l})+3 \mathrm{H}_2 \mathrm{O}$ (l) .The rate of appearance of bromine $\left(\mathrm{Br}_2\right)$ is related to rate of disappearance of bromide ions as following

Official previous-year question

Held on 30 Apr 2009 · Verified 9 Jul 2026.

Options

A
$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$
B
$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$
C
$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$
D
$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

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Solution

Key Idea Rate of appearance/disappearance $= \pm \frac{1}{\begin{array}{l} \text { stoichiometric } \\ \text { coefficient } \end{array}} \times \frac{\text { [reactant or product] }}{\text { time taken }}$ For reaction, $\begin{aligned} \mathrm{BrO}_3^{-}(\mathrm{aq})+5 \mathrm{Br}^{-}(\mathrm{aq})+6 \mathrm{H}^{+} \longrightarrow & 3 \mathrm{Br}_2(1) \\ & +3 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \end{aligned}$ Rate of appearance of bromine $\left(\mathrm{Br}_2\right)$ $=+\frac{1}{3} \frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}$ Rate of disappearance of bromide ion $\left(\mathrm{Br}^{-}\right)$ $=-\frac{1}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$ or $\quad \frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

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$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

$\frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$

Solution

NEET UG 2009 — Chemistry Physical Chemistry

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NEET UG 2009 — Chemistry Physical Chemistry

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NEET UG Physical Chemistry in other years

More NEET UG Physical Chemistry questions

Other Chemistry topics for NEET UG

Organic Chemistry

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