Question

For a reaction, `X(g) rarr Y(g) + Z(g)`. The half-life periof is `10 min`. In what periof of time would the concentration of `X` be reduced to `10%` of the original concentration ?
A. `20` min
B. `33` min
C. `15` min
D. `25` min

Answer 1

Correct Answer - B
`x_((g)) rarr y_((g)) + z_((g))`
The reaction is a first-order reaction hence,
`K = (0.693)/(t_(1//2)) = (2.303)/(t) "log"(a)/(a-x)`
`= (0.693)/(10 min)`
`= (2.303)/(t) "log"(a)/(a//10)`
`= (0.693)/(10) = (2.303)/(t)log 10`
`t = (2.303 xx 10)/(.693) = 33 min`