Question

The following reaction was carried out in water
`Cl_(2) + 2I^(-) to 2Cl^(-) + I_(2)`
The initial concentration of `I^(-)` was `0.50 mol L^(-1)` and concentration after 10 minutes was 0.46 mol `L^(-1)`. Calculate the rate of disappearance of `I^(-)` and rate of appearance of `I_(2)`.

Answer 1

The chemicaal reaction is: `Cl_(2) + 2I^(-) to 2Cl^(-) +I_(2)`
`Delta[I^(-)]=(0.046 -0.50) = -0.04 mol L^(-1)`, `Deltat=10min`.
Rate of disappearance of `I^(-)`
`-(Delta[I^(-)])/(Deltat) = -(0.04 mol L^(-1))/(10 "min")=0.004 mol L^(-1)min^(-1)`
Rate of appearance of `I_(2)`.
`(Delta[I_(2)])/(Deltat) = 1/2(Delta[I^(-)])/(Deltat) = 0.04/2 mol L^(-1)min^(-1) = 0.002 mol L^(-1)min^(-1)`.