Question

The pH of a solution of $H_2{O}_2$ is 6.0. Some chlorine gas is bubbled into this solution. Which of the following is correct?

• A. The pH of the resulting solution becomes 8.
• B. Hydrogen gas is liberated from the resultant solution.
• C. The pH of the resultant solution becomes less than 6.0 and oxygen gas is liberated.
• D. $C{l}_{2}O$ is formed in the resultant solution.

Answer 1

The correct option is C The pH of the resultant solution becomes less than 6.0 and oxygen gas is liberated.

$H_2{O}_2\to H_{2}O+O_2$
$C{l}_2+H_{2}O+O_2\to 2HCl+O_2$
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$C{l}_2+H_2{O}_2\to 2HCl+O_2$
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Due to the formation of strong acid HCl, the pH of the solution will decrease along with the formation of $O_2$ gas.