For the reaction , `Cl_(2)+2I^(-) rarr I_(2)+2Cl^(-)`, the initial concentration of `I^(-)` was `0.20 "mol lit"^(-1)` and the concentration after 20 minutes was `0.80 "mol lit"^(-1)`. Then the rate of formation of `I_(2) "in mol lit"^(-1) "min"^(-1)` would be

Options

A. `1 xx 10^(-3)`
B. `5 xx 10^(-4)`
C. `1 xx 10^(-4)`
D. `2 xx 10^(-3)`

Answer

B

Explanation

Rate of disapearance of `I^(-)`
`-(Delta[I^(-)])/(Deltat)=((0.20-0.18)"mol L"^(-1))/(20 min)`
Rate of reaction `=-(1)/(2)(Delta[I^(-)])/(Deltat)=+(Delta[I_(2)])/(Delta t)`
`:.` Rate of formation of `I_(2)`
`(Delta [I_(2)])/(Deltat)=-(1)/(2)([I^(-)])/(Deltat)=(10^(-3))/(2)`
`=5xx10^(-4)"mol L"^(-1)"min"^(-1)`.