Reaction `2Br_((aq.))^(-)+Cl_(2(aq.))rarr2Cl_((aq.))^(-)+Br_(2(aq.))`, is used for commercial preparation of bromine from its salts. Suppose we have `50 mL` of a `0.060M` solution of `NaBr`. What volume of a `0.050 M` solution of `Cl_(2)` is needed to react completely with the `Br` ?

Explanation

`2Br^(-) + Cl_(2) rarr2Cl^(-) + Br_(2)`
or `2br^(-) rarr Br_(2)^(0) + 2e`
("Valence factor for" `Br^(-1) = 1`)
`Cl_(2)^(0) + 2e rarr 2Cl^(-)` ("Valence factor for" `Cl_(2) = 2`)
`"Meq. of" Cl_(2) = "Meq. of" Br^(-)`
0.05 xx 2 xx V = 50 xx 0.60 xx 1`
`V = 300 mL`