Question

A litre of methane gas, \({\rm{C}}{{\rm{H}}_4}\), at STP contains more atoms of hydrogen than does a litre of pure hydrogen gas, \({{\rm{H}}_2}\), at STP. Using Avogadro's law as a starting point, explain why.

Short answer

Therefore, a litre of methane gas at STP contains more atoms of hydrogens than does a litre of pure hydrogen gas.

Step-by-step solution

Step 1: Avogadro's law

Avogadro's law asserts that equal volumes of various gases contain an equal number of molecules at the same temperature and pressure.

Explanation

The number of Avogadro's molecules in one litre of methane gas and one litre of pure hydrogen gas at STP is the same.

However, one methane molecule has four hydrogen atoms, whereas the hydrogen gas has two hydrogen atoms.