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The following data was obtained for a hypothetical reaction S. No. (mol ) (mol ) Initial rate (mol…
The following data was obtained for a hypothetical reaction $2A + B \rightarrow 2AB$
The rate law expression for this reaction is:
| S. No. | $[A]$ (mol $L^{-1}$) | $[B]$ (mol $L^{-1}$) | Initial rate (mol $L^{-1}$ $s^{-1}$) |
|---|---|---|---|
| 1 | $0\cdot5$ | $0\cdot5$ | $1\cdot8 \times 10^{-4}$ |
| 2 | $1\cdot0$ | $0\cdot5$ | $3\cdot6 \times 10^{-4}$ |
| 3 | $1\cdot0$ | $1\cdot0$ | $3\cdot6 \times 10^{-4}$ |
- arate $= k[A]^1[B]^1$
- brate $= k[A]^1[B]^0$
- crate $= k[A]^2[B]^1$
- drate $= k[A]^0[B]^1$
Answer
Answer
Checked answer.
Correct option: b
Answer: (b) rate $= k[A]^1[B]^0$
Experiments 1 and 2: $[B]$ is fixed and $[A]$ is doubled ($0\cdot5 \to 1\cdot0$); the rate doubles ($1\cdot8 \times 10^{-4} \to 3\cdot6 \times 10^{-4}$), so the order with respect to A is 1.
Experiments 2 and 3: $[A]$ is fixed and $[B]$ is doubled; the rate does not change, so the order with respect to B is 0.
Hence rate $= k[A]^1[B]^0$.
From ISC 2027 Specimen Chemistry Paper 1, question 1(B)(iv).