[单选题]
A reaction involving
yus9zylf+3m7 a0+x-tqo :gzs$X$ and $Y$ is measured and the following data is found:
| Trial | $[X]$$(mol dm^{-3})$ | $[Y]$$(mol dm^{-3})$ | $Rate$$(s^{-1})$ |
| 1 | 0.10 | 0.50 | 0.20 |
| 2 | 0.20 | 0.50 | 0.40 |
| 3 | 0.20 | 0.25 | 0.40 |
What possible mechanism is consistent with the data?
A. $X$+$X$→$I$(slow) $I$+$Y$→$Z$ (fast)
B. $X$+$Y$→$I$(fast) $I$→$Z$ (slow)
C. $X$→$I$(slow) $I$+$Y$→$Z$ (fast)
D. $X$→$I$(fast) $I$+$Y$→$Z$ (slow)
参考答案:
C
本题详细解析:
C
Using trials 1 and 2, as $[X]$ doubles, rate also doubles therefore first order with respect to $[X]$.
Using trials 2 and 3, as $[Y]$ halves, rate stays the same and so, zero order with respect to $[Y]$.
This gives a slow step that depends on unimolecular $X$, and not $Y$.
