Question

The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: Experiment A/ mol L−1 B/ mol L−1 Initial rate/mol L−1 min−1 I 0.1 0.1 2.0 × 10−2 II -- 0.2 4.0 × 10−2 III 0.4 0.4 -- IV -- 0.2 2.0 × 10−2

Answer 1

The given reaction is of the first order with respect to A and of zero order with respect to B.

From experiment II, we obtain

   4.0 x 10-2 mol / (L min) = 0.2 min^(-1) [A]

⇒ [A] = 0.2 mol/L

From experiment IV, we obtain

   2.0 x 10-2 mol / (L min) = 0.2 min^(-1) [A]

⇒ [A] = 0.1 mol/L

Answer 2

Fill in the blanks:

The table given in the question is attached below.

From question, we know that the given reaction is of the first order with respect to A and of zero order with respect to  B.

The rate of the reaction is given by the formula:

$\bold{\text { Rate }=k[\mathrm{A}]^{x}[\mathrm{B}]^{y}}$

From question x = 1 and y = 0

$\bold{\text { Rate }=k[\mathrm{A}]^{1}[\mathrm{B}]^{0}}$

$\bold{\therefore \text { Rate }=k[\mathrm{A}]}$

Experiment I:

From table, we can obtain the required values for experiment 1.

$\bold{2.0 \times 10^{-2} \mathrm{mol} \mathrm{L}^{-1} \mathrm{min}^{-1}=\mathrm{k}\left(0.1 \mathrm{mol} \mathrm{L}^{-1}\right)}$

$\bold{\therefore k=0.2 \ \mathrm{min}^{-1}}$

Experiment II:

From table, we can obtain the required values for experiment 2.

$\bold{4.0 \times 10^{-2} \mathrm{mol} \mathrm{L}^{-1} \mathrm{min}^{-1}=0.2 \mathrm{min}^{-1}[\mathrm{A}]}$

$\bold{\therefore [\mathrm{A}]=0.2 \ \mathrm{mol} \mathrm{L}^{-1}}$

Experiment III:

From table, we can obtain the required values for experiment 3.

$\bold{k=0.2 \ \mathrm{min}^{-1} \times 0.4 \ \mathrm{mol} \mathrm{L}^{-1}}$

$\bold{k=0.08 \ \mathrm{mol} \mathrm{L}^{-1} \mathrm{min}^{-1}}$

Experiment IV:

From table, we can obtain the required values for experiment 4.

$\bold{2.0 \times 10^{-2} \mathrm{mol} \mathrm{L}^{-1} \mathrm{min}^{-1}=0.2 \mathrm{min}^{-1}[\mathrm{A}]}$

$\bold{\therefore [\mathrm{A}]=0.1 \ \mathrm{mol} \mathrm{L}^{-1}}$