Which of the following expressions is correct for rate of reaction given below?
`5Br_((aq))^(-)+BrO_(3(aq))^(-)+6H_((aq))^(-)to3BR_(2(aq))+3H_(2)O_((i))`

Options

A. `(Delta[Br^(0)])/(Deltat)=5(Delta[H^(+)])/(Deltat)`
B. `(Delta[Br^(-)])/(Deltat)=(6)/(5)(DeltaH^(+))/(Deltat)`
C. `(Delta[Br^(-)])/(Deltat)=(5)/(6)(Delta[H^(+)])/(Deltat)`
D. `(Delta[Br^(-)])/(Deltat)=6(Delta[H^(+)])/(Deltat)`

Answer

C

Explanation

The balance equation of reaction is:
`5Br_((aq))^(-)+BrO_(aq)^(-)+6H_((aq))^(+)to3Br_(2(aq))+3H_(2)O_(l)`
aqueous medium is given ,so except `H_(2)O_(l)` for all species the rate is as follows (in which coefficient is `(1)/(x)`) and with respect to reactant -ve and with respect to product the rate is +ve.
Rate=`-(1)/(5)(Delta[Br^(-)])/(Delta t)=-(Delta[BrO_(3)^(-)])/(Deltat)`
`-(1)/(6)([DeltaH^(+)])/(Deltat)=+(1)/(3)([DeltaBr_(2)])/(Deltat)`
`therefore (Delta[Br^(-)])/(Deltat)=(5Delta[BrO_(3)^(-)])/(Deltat)`
`(5)/(6)([DeltaH^(+)])/(Deltat)=-(5)/(3)([DeltaBr_(2)])/(Deltat)`
`therefore ([DeltaBr^(-)])/(Deltat)=+(5)/(6)(DeltaH^(+))/(Deltat)` So, option (C )is correct.