Question

What pH is needed to produce this value of Q if the concentration and pressure values are [Br2]=2.50×10?4M, [Br?]=11.85M, [SO42?]=8.35M, and PSO2=2.50×10?5atm? Express your answer numerically to two decimal places. q=1.4x10^-26

Answer 1

Explanation:

The given reaction will be as follows.

       $2H_{2}O + Br_{2} + SO_{2} \rightarrow 2Br^{-} + SO^{2-}_{4} + 4H^{+}$

Hence, expression that represents relation between given reaction and Q will be as follows.

              Q = $\frac{[Br^{-}]^{2}[SO^{2-}_{4}][H^{+}]^{4}}{[Br_{2}]P_{SO_{4}}}$

          $1.4 \times 10^{-26}$ = $\frac{(11.85)^{2} \times (8.35) \times [H^{+}]^{4}}{(2.5 \times 10^{4}) \times 2.50 \times 10^{5}}$

                $[H^{+}]^{4} = 7.46 \times 10^{-34}$

                 $[H^{+}]= 5.22 \times 10^{-10}$

As relation between pH and $[H^{+}]$ is as follows.

                     pH = -log $[H^{+}]$

                           = -log $5.22 \times 10^{-10}$

                           = -(0.717 - 10)

                           = 9.28

Thus, we can conclude that the pH needed to produce the given value of Q is 9.28.