Consider the reaction,
`Cl_(2)(aq) + H_(2)S(aq) rarr S(s) + 2H^(+) (aq) + 2Cl^(-)(aq)`
The rate equation for this reaction is,
Rate `=k [Cl_(2)][H_(2)S]`
Which of these mechanisms is`//`are consistent with this rate equation ?
(I) `Cl_(2) + H_(2)S rarr H^(+) + Cl^(-) + Cl^(+) + HS^(-)` (slow)
`Cl^(+) + HS^(-) rarr H^(+) + Cl^(-) + S` (fast)
(II) `H_(2)S hArr H^(+) +HS^(-)` (fast equilibrium)
`Cl^(+) + HS^(-) rarr 2 Cl^(-) + H^(+) + S` (slow)

Options

A. (a) `2 only`
B. (b) `Both 1 and 2`
C. (c ) `Neither 1 nor 2`
D. (d) `1 only`

Answer

d

Explanation

Rate depends upon the slow step, thus slow step should involve `1` molecule of `Cl_(2)` and `1` molecule of `H_(2)S`.
Hence, `1` is the correct mechanism.
Rate=`K[Cl_(2)][H_(2)S]`