Question

after combustion with excess oxygen, 12.501 g of a petroleum compound made of c and h produced 38.196 g co₂ and 18.752 g h₂o. how many moles of hydrogen are used? ? moles h used hint: get the h out of the h₂o.

Explanation:

Step1: Calculate moles of \(H_2O\)

Molar mass of \(H_2O\) is \(18.015\space g/mol\). Moles of \(H_2O=\frac{mass}{molar\space mass}=\frac{18.752\space g}{18.015\space g/mol}\approx1.041\space mol\)

Step2: Determine moles of H

In \(1\space mol\) of \(H_2O\), there are \(2\space mol\) of H. So moles of H \(= 2\times\) moles of \(H_2O = 2\times1.041\space mol = 2.082\space mol\)

Answer:

\(2.082\)