Question

For the hypothetical reaction A → B, calculate the average rate of disappearance of A if the initial concentration of A is 0.91 M and the concentration of A after 90 minutes is 0.11 M.
a. 8.9 * 10^-3 M/min
b. -8.9 * 10^-3 M/min
c. 8.9 * 10^-3 M/min
d. 0.80 M/min

Answer 1

Answer: The average rate of disappearance of A is $8.9\times 10^{-3}M/min$

Explanation:

The given chemical reaction follows:

$A\rightarrow B$

The average rate of the reaction for disappearance of A is given as:

$\text{Average rate of disappearance of A}=-\frac{\Delta [A]}{\Delta t}$

Or,

$\text{Average rate of disappearance of A}=-\frac{C_2-C_1}{t_2-t_1}$

where,

$C_2$ = final concentration of A = 0.11 M

$C_1$ = initial concentration of A = 0.91 M

$t_2$ = final time = 90 minutes

$t_1$ = initial time = 0 minutes

Putting values in above equation, we get:

$\text{Average rate of disappearance of A}=-\frac{0.11-0.91}{90}\\\\\text{Average rate of disappearance of A}=8.9\times 10^{-3}M/min$

Hence, the average rate of disappearance of A is $8.9\times 10^{-3}M/min$