help If we started with a 0500 M solution of crystal violet

help!

If we started with a 0.500 M solution of crystal violet and an excess of hydroxide, based on your results how long would it take for the concentration to be reduced to 0.123 M

Solution

For first order reaction

ln A = - k * t + ln A0

Initial concentration A0 = 0.500 M

Final concentration A = 0.123 M

ln (0.123) = - 0.00167 * t + ln (0.500)

ln (0.123) - ln (0.500) = - 0.00167 * t

t = 839.77 s