Question

$50$ mL of $CO$ is mixed with $20$ mL of oxygen and sparked. After the reaction, the mixture is treated with an aqueous $KOH$ solution. Choose the correct option.

• A. The volume of $CO$ that reacts is $30$ mL.
• B. The volume of $C{O}_2$ formed is $50$ mL.
• C. The volume of $CO$ that remains after treatment with $KOH$ is $10$ mL.
• D. The volume of the $CO$ that remains after treatment with $KOH$ is $20$ mL.

Answer 1

The correct option is C The volume of $CO$ that remains after treatment with $KOH$ is $10$ mL.

The reaction is as folllows:

$2CO+O_2\to 2C{O}_2$
$1$ mole of oxygen reacts with $2$ moles of $CO$ to form $2$ moles of $C{O}_2$.
$20$ mL of oxygen reacts with $40$ mL of $CO$ to form $40$ mL of $C{O}_2$.
Oxygen reacts completely and the mixture contains $10$ mL of $CO$ and $40$ mL of $C{O}_2$.
When this mixture is passed through aqueous $KOH$ solution, $40$ mL of $C{O}_2$ dissolves and $10$ mL of $CO$ remains.