Question

in the course of the combustion analysis of an unknown compound containing only carbon, hydrogen, and nitrogen, 6.462 g of carbon dioxide and 3.304 g of water were measured. how many moles of hydrogen are in the sample?
0.1468 mol c : ? mol h : mol n
do not round! include lots of digits in your answer since this is part of a larger calculation.

Explanation:

Step1: Find moles of water

Molar mass of \(H_2O\) is \(18.015\space g/mol\). Moles of \(H_2O=\frac{mass}{molar\space mass}=\frac{3.304\space g}{18.015\space g/mol}\)
\[=\frac{3.304}{18.015}\approx0.1834\space mol\]

Step2: Relate moles of H to moles of \(H_2O\)

In \(H_2O\), each mole has 2 moles of H. So moles of H \(= 2\times\) moles of \(H_2O\)
\[=2\times0.1834 = 0.3668\space mol\]

Answer:

\(0.3668\)