For and elementary reaction
`2A underset(k_(2))overset(k_(1))hArr B`, the rate of disappearance of `A` iss equal to
(a) `(2k_(1))/(k_(2))[A]^(2)`
(b) `-2k_(1)[A]^(2) + 2k_(2)[B]`
( c) `2k_(1)[A]^(2) - 2k_(2)[B]`
(d) `(2k_(1) - k_(2))[A]`

Explanation

(c ) Rate o f reaction `= -(1)/(2)(d[A])/(dt) = k_(1)[A]^(2) - k_(2)[B]`
`:.` Rate of disappearance f `A`
`= (-d[A])/(dt) = 2k_(1)[A]^(2) - 2k_(2)[B]`