Question

If 75% of a frist-order reaction is completed in 32 min, than 50% of the reaction would complete in?
a. 24 min b. 16 min c. 8 min d. 4 min
A. a. 24 min
B. b. 16 min
C. c. 8 min
D. d. 4 min

Answer 1

Correct Answer - b. 16 min
Use direct formula `(t_(x%))/(t_(y%)) = ("log" (a)/(a - x))/("log" (a)/(a - y))`
`:. (t_(50%))/(t_(75%)) = ("log" (100)/(100 - 50))/("log" (100)/(100 - 75)) implies t_(50%) = (t_(75%))/(2)`
`:.t_(32)/(2) = 16 "min"`