| The bromination of acetone that occurs in acid solution is represented by this equation. [AIPMT (S) 2008] |
| \[C{{H}_{3}}COC{{H}_{3}}(aq)+B{{r}_{2}}(aq)\xrightarrow[{}]{{}}\]\[C{{H}_{3}}COC{{H}_{2}}Br(aq)+{{H}^{+}}(aq)+B{{r}^{-}}(aq)\] |
| These kinetic data were obtained for given reaction concentrations. |
| Initial concentrations, M |
| \[[C{{H}_{3}}COC{{H}_{3}}]\] \[[B{{r}_{2}}]\] \[[{{H}^{+}}]\] |
| 0.30 0.05 0.05 |
| 0.30 0.10 0.05 |
| 0.30 0.10 0.10 |
| 0.40 0.05 0.20 |
| Initial rate, disappearance of \[B{{r}_{2}},M{{s}^{-1}}\] |
| \[5.7\times {{10}^{-5}}\] |
| \[5.7\times {{10}^{-5}}\] |
| \[1.2\times {{10}^{-4}}\] |
| \[3.1\times {{10}^{-4}}\] |
| Based on these data, the rate equation is |
A) Rate \[=k[C{{H}_{3}}COC{{H}_{3}}][{{H}^{+}}]\]
B) Rate \[=k[CH=COC{{H}_{3}}][B{{r}_{2}}]\]
C) Rate \[=k[C{{H}_{3}}COC{{H}_{3}}][B{{r}_{2}}]{{[{{H}^{+}}]}^{2}}\]
D) Rate \[=k[C{{H}_{3}}COC{{H}_{3}}][B{{r}_{2}}]{{[{{H}^{+}}]}^{2}}\]
Correct Answer: A
Solution :
| [a] Key Idea: By comparing the rate and concentration, the order of the reaction can be calculated. |
| Let the rate of the reaction wrt \[[C{{H}_{3}}COC{{H}_{3}}],\]\[[B{{r}_{2}}]\] and \[[{{H}^{+}}]\] are x, y and z respectively. Thus, |
| Rate \[\propto {{[C{{H}_{3}}COC{{H}_{3}}]}^{x}}{{[B{{r}_{2}}]}^{y}}{{[{{H}^{+}}]}^{z}}\] |
| \[5.7\times {{10}^{-5}}={{[0.30]}^{x}}{{[0.05]}^{y}}{{[0.05]}^{z}}\] (i) |
| \[5.7\times {{10}^{-5}}={{[0.30]}^{x}}{{(0.10)}^{y}}{{(0.05)}^{z}}\] (ii) |
| \[1.2\times {{10}^{-4}}={{[0.30]}^{x}}{{(0.10)}^{y}}{{(0.10)}^{z}}\] (iii) |
| \[3.1\times {{10}^{-4}}={{[0.40]}^{x}}{{(0.05)}^{y}}{{(0.20)}^{z}}\] (iv) |
| From Eqs (i) and (ii) |
| y = 0 |
| From Eqs (ii) and (iii) |
| x = 1 |
| From, Eqs (i) and (iv) |
| x = 1 |
| Thus, rate law \[\propto [C{{H}_{3}}COC{{H}_{3}}][{{H}^{+}}]\] |
| \[=k[C{{H}_{3}}COC{{H}_{3}}][{{H}^{+}}]\] |
You need to login to perform this action.
You will be redirected in
3 sec
