NEET 2009
- Exam
- NEET
- Year
- 2009
- Subject
- Chemistry
- Chapter
- Chemical Kinetics
NEET 2009 · Chemistry · Chemical Kinetics
In the reaction, (BrO_3^ - )(aq.) (+5 Br^ - )(aq.) (+6 H^ + )(aq.)...
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 is related to rate of disappearance of bromide ions as following
Options
- A\frac{\mathrm{d}\left[\mathrm{\text{ Br }}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}
- B\frac{\mathrm{d}\left[\mathrm{\text{ Br }}_2\right]}{\mathrm{dt}}=-\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}
- C\frac{\mathrm{d}\left[\mathrm{\text{ Br }}_2\right]}{\mathrm{dt}}=\frac{5}{3} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}
- D\frac{\mathrm{d}\left[\mathrm{\text{ Br }}_2\right]}{\mathrm{dt}}=\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}
Correct answer
A. \frac{\mathrm{d}\left[\mathrm{\text{ Br }}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}
Step-by-step solution
Key Idea Rate of appearance/disappearance
= \pm \frac{1}{\begin{\text{ array }}{l}
\text{ stoichiometric } \\
\text{ coefficient }
\end{\text{ 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\rright]}{\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 \frac{\mathrm{d}\left[\mathrm{Br}_2\right]}{\mathrm{dt}}=-\frac{3}{5} \frac{\mathrm{d}\left[\mathrm{Br}^{-}\right]}{\mathrm{dt}}$