For a reaction (A \xrightarrow{K\_1} B \xrightarrow{K\_2} C)... | Chemistry | SolveeIt

Question

For a reaction $A \xrightarrow{K_1} B \xrightarrow{K_2} C$ If the rate of formation of B is set to be zero then the concentration of B is given by:

$K_1K_2[A]$

$(K_1 - K_2)[A]$

$(K_1 + K_2)[A]$

$(K_1/K_2)[A]$

Answer

$(K_1/K_2)[A]$

Explanation

Solution

The rate of formation of B is:
$\frac{d[\text{B}]}{dt} = k_1[\text{A}] - k_2[\text{B}].$
For the rate of formation of B to be zero:
$\frac{d[\text{B}]}{dt} = 0.$
Substitute:
$k_1[\text{A}] - k_2[\text{B}] = 0.$
Rearrange to find [B]:
$k_1[\text{A}] = k_2[\text{B}] \implies [\text{B}] = \frac{k_1}{k_2}[\text{A}].$
Thus, the concentration of B is:
$[\text{B}] = \left(\frac{k_1}{k_2}\right)[\text{A}].$

Chemistry Question on Chemical Kinetics

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