# Problem: Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.How many moles of oxygen are collected?

###### FREE Expert Solution

Solve for PO→ moles O2

Using Dalton’s Law: PO2
at 25.0°C, Pwater = 23.78 mm Hg (vapor pressure)

${\mathbit{P}}_{{\mathbf{O}}_{\mathbf{2}}}\mathbf{=}$739.82 mmHg

Ideal Gas equation: moles O2

$\mathbf{PV}\mathbf{=}\mathbf{nRT}\phantom{\rule{0ex}{0ex}}\overline{){\mathbf{n}}{\mathbf{=}}\frac{\mathbf{PV}}{\mathbf{RT}}}$

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###### Problem Details

Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.

How many moles of oxygen are collected?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Collecting Gas Over Water concept. If you need more Collecting Gas Over Water practice, you can also practice Collecting Gas Over Water practice problems.