Question

what volume of oxygen gas is produced when 1.89 mol of hydrogen peroxide (h2o2) reacts completely according to the following reaction at 0°c and 1 atm? hydrogen peroxide (h2o2) (aq) → water (l) + oxygen (g)

Explanation:

Step1: Write balanced chemical equation

$$2H_2O_2(aq) ightarrow 2H_2O(l)+O_2(g)$$

Step2: Determine mole ratio

From the equation, mole ratio of \(H_2O_2\) to \(O_2\) is \(2:1\). Given \(n_{H_2O_2}=1.89\ mol\), then \(n_{O_2}=\frac{1.89\ mol}{2}=0.945\ mol\)

Step3: Use ideal gas law (\(V=\frac{nRT}{P}\)) at STP (\(T = 273\ K\), \(P=1\ atm\), \(R = 0.0821\ L\cdot atm/(mol\cdot K)\))

\(V=\frac{0.945\ mol\times0.0821\ L\cdot atm/(mol\cdot K)\times273\ K}{1\ atm}\)
\(V = 21.1\ L\)

Answer:

\(21.1\) liters