The following reaction was monitored as a function of time: A→B+C A plot of ln[A] versus time yields a straight line with slope −4.3×10−3 /s. If the initial concentration of A is 0.260 M, what is the concentration after 225 s?

Answer : The concentration after 225 s is, 0.099 M

Explanation :

As we know that, the graph of ln [A] versus time yields a straight line with slope 'k'.

So, Slope = k =

Expression for rate law for first order kinetics is given by:

where,

k = rate constant  =

t = time passed by the sample  = 225 s

a = initial amount of the reactant  = 0.260 M

a - x = amount left after decay process = ?

Now put all the given values in above equation, we get

Therefore, the concentration after 225 s is, 0.099 M