Question

For the reaction $\ce{H^+ + BrO_3 ^- + 3Br^- -> 5Br+2 + H_2O}$ which of the following relation correctly represents the consumption & formation of reactants and products :

• A. $\frac{d [Br_2]}{dt} =-\frac{5}{3} \frac{d [Br^-]}{dt}$
• B. $\frac{d [Br_2]}{dt} =- \frac{d [Br^-]}{dt}$
• C. $\frac{d [Br_2]}{dt} =\frac{3}{5} \frac{d [Br^-]}{dt}$
• D. $\frac{d [Br_2]}{dt} =-\frac{3}{5} \frac{d [Br^-]}{dt}$

Answer 1

Answer: (A)

Rate of disappearance of reactant
= Rate of appearance of product
$ -\frac{1}{5}\frac{d [Br^-]}{dt} =+\frac{1}{3} \frac{d [Br_2]}{dt}$
or $ \, \, \, \, \, \, \, \frac{d [Br_2]}{dt}=-\frac{3}{5}\frac{d [Br^-]}{dt}$