Avogadro's Law Flashcards

All 4 cards in this deck

State Avogadro's law.

Equal volumes of different gases at the same temperature and pressure contain equal numbers of molecules.

In a reaction between gases at the same temperature and pressure, what does the ratio of their volumes equal?

The mole ratio of the gases in the balanced equation.

What are the steps to use Avogadro's law to find the volume of a gaseous product?

e.g. $30\ \mathrm{cm^3}$ of hydrogen reacting completely in $\mathrm{N_2 + 3H_2 \rightarrow 2NH_3}$

1. Read the mole ratio from the equation: H$_2$ : NH$_3$ = 3 : 2
2. Gas volumes are in the same ratio as the moles
3. Volume of NH$_3$ = $30 \times \frac{2}{3} = 20\ \mathrm{cm^3}$

True or false? Avogadro's law can be used to compare the volumes of solid reactants as well as gases.

False. It applies only to gases at the same temperature and pressure.