Define average rate of a reaction. How is the rate of reaction expressed in term of charge in the concentration of reactansts and products for the following reactions.
1) `2HI_((g))to H_(2(g))+I_(2(g))`
2) `Hg_((l))+CL_(2(g))to Hg Cl_(2(g))`
3) `5 Br _((aq))+ BrO_((aq))^(-) +6H_((aq))^(+)to 3 Br _(2(aq)) +3H_(2) O_((l))`

Explanation

Average rate of a reaction : The change in the concentration of any one of the reactant or products per unit time is called averatge rate of a reaction.
1) `2HI _((g))to H_(2_((g)))I _(2(g))`
Rate of reaction `=-1/2 (Delta[HI])/(Deltat)=(Delta[H_(2)])/(Deltat)=(Delta[I_(2)])/(Deltat)`
2) `Hg_((l))+Cl_(2(g))to HgCl_(2(g))`
Rate of reaction `=(Delta[Hg])/(Deltat)=-(Delta[Cl_(2)])/(Deltat)=(Delta[HgCl_(2)])/(Deltat)`
3) `5 Br_((aq))^(-) + BrO_(3(aq))^(-)+6H_((aq))^(+)to 3 Br _(2(aq))+3H_(2)O_((l))`
Given reaction is `5 Br_((aq))^(-) +BrO_((aq))^(-)+6H_((aq))^(+)to 3 Br _(2(aq))+3H_(2)O_((l))`
Rate of reaction `=-1/5 (Delta[Br ^(-)])/(Deltat)=(-Delta[Br O_(3)^(-)])/(Deltat)=(-1)/(6)(Delta[H^(+)])/(Deltat)=(-1)/(3)(Delta[Br_(2)])/(Deltat)=1/3 (Delta[H_(2)O])/(Deltat)`