Question

question 13 (1 point)
if equal masses of hydrogen and oxygen are combined and ignited, according to the equation:
2 h₂ + o₂ → 2 h₂o
then,
none of the gases react
excess hydrogen will remain
excess oxygen will remain
both gases react completely

Explanation:

Step1: Calculate molar masses

Molar mass of \(H_2 = 2\space g/mol\), molar mass of \(O_2=32\space g/mol\).

Step2: Assume equal masses

Let the mass of \(H_2\) and \(O_2\) be \(m\space g\). Moles of \(H_2=\frac{m}{2}\), moles of \(O_2 = \frac{m}{32}\).

Step3: Use stoichiometry

From \(2H_2+O_2
ightarrow 2H_2O\), mole ratio \(H_2:O_2 = 2:1\). For \(\frac{m}{32}\space mol\) of \(O_2\), moles of \(H_2\) required \(= 2\times\frac{m}{32}=\frac{m}{16}\). But we have \(\frac{m}{2}\space mol\) of \(H_2\). Since \(\frac{m}{2}>\frac{m}{16}\), excess \(H_2\) is present.

Answer:

Excess hydrogen will remain