How do mole ratios compare to volume ratios?
So, according to Avogadro's law, equal volumes of ideal gases contain the same number of moles at the same temperature and pressure. This means that if pressure and temperature are held constant, 1 mole of any ideal gas will occupy the exact same volume.
The most common application of this principle is the molar volume of a gas at STP - Standard Temperature and Pressure. At STP conditions, which imply a temperature of 273.15 K and a pressure of 1 atm, 1 mole of any ideal gas occupies exactly 22.4 L.
So, let's say you have a reaction that involves ideal gases at STP.
The mole ratio between
Let's assume we have
The volume ratio between
So, for gaseous reactants and products that are at the same temperature and pressure, the mole ratio is equal to the volume ratio.