Answer:
The average rate of the reaction in terms of disappearance of A is 0.0004 M/s.
Explanation:
Average rate of the reaction is defined as ratio of change in concentration of reactant with respect to given interval of time.
[tex]R_{avg}=-\frac{[A]_2-[A]_1}{t_2-t_1}[/tex]
Where :
[tex]A_1[/tex] = initial concentration of reactant at [tex]t_1[/tex].
[tex]A_2[/tex] = Final concentration of reactant at [tex]t_2[/tex].
2A+3B → 3C+2D
[tex]R_{avg}=-\frac{1}{2}\frac{[A]_2-[A]_1}{t_2-t_1}[/tex]
The concentration of A at ([tex]t_1=0 seconds[/tex] ) = [tex]A_1=0.0400 M[/tex]
The concentration of A at ([tex]t_2=20 seconds[/tex] ) = [tex]A_2=0.0240 M[/tex]
The average rate of reaction in terms of the disappearance of reactant A in an interval of 0 seconds to 20 seconds is :
[tex]R_{avg}=-\frac{1}{2}\times \frac{0.0240 M-0.0400 M}{20-0}=0.0004 M/s[/tex]
The average rate of the reaction in terms of disappearance of A is 0.0004 M/s.
