the gaseous reaction A2---> 2a is first order in A2 .after 12.3 minutes 65% of A2 remains undecomposed . how long will it take to decompose 90% of A2 ?what is the half life of the reaction?
Dear Student,
As this is a 1st order reaction,
So, ln A = -kt + ln Ao
i.e. ln (0.65) = - (k) (738 s) + ln 1.00 [65% means 0.65 if total conc. initially was 1 i.e. Ao = 1, 12.3 min = 738 s]
or, k = 0.000584010 s-1.
Now, to decompose 90% means 10% remains. So, putting this in equation,
ln A = -kt + ln Ao
ln 0.100 = - ( 0.000584010 s-1) (t) + ln 1.00
t = 3943 s i.e. almost 66 minutes.
Half life of reaction =
Regards
As this is a 1st order reaction,
So, ln A = -kt + ln Ao
i.e. ln (0.65) = - (k) (738 s) + ln 1.00 [65% means 0.65 if total conc. initially was 1 i.e. Ao = 1, 12.3 min = 738 s]
or, k = 0.000584010 s-1.
Now, to decompose 90% means 10% remains. So, putting this in equation,
ln A = -kt + ln Ao
ln 0.100 = - ( 0.000584010 s-1) (t) + ln 1.00
t = 3943 s i.e. almost 66 minutes.
Half life of reaction =
Regards