# How does gas stoichiometry differ from stoichiometry of solids and liquids?

Apr 23, 2014

All that changes is how the relevant information is presented. The core of all stoichiometry problems is the mole-mole relationship established by the balanced equation.

The tricky part is getting the units given to you into moles so that you can find the substance in question through the mole-mole ratio.

Solid stoichiometry might start you with mass. Well, you'd typically use molar mass to get to moles.

Liquid or solution stoichiometry might start you with a volume. Well, you might need a concentration (in mol/L) to convert that to the moles. Maybe instead if it's a pure substance, you'd use density to get to mass and then to moles (ala molar mass).

Gas stoichiometry might involve information about pressure, volume, temperature, etc. A lot of times you might have to set up an Ideal Gas problem (PV=nRT) to find the moles of something (n=PV/(RT)).

One you've converted to moles of the second substance you'll use the same tenacity to work through to the requested units, be they grams, liters, pounds, etc.