Beginning with the proportionality,

the following equation can be derived,

Substituting for each of the variables as defined by the conditions in Table 1 for an ‘ideal’ gas gives,

This constant is given the symbol "R" and is called the ideal gas constant.

In summary,

or as it is normally written,

PV=nRT

This equation is called the ideal gas law.

If all of the liquid butane, C₄H₁₀, contained in a full lighter were released, what volume would the butane, C₄H₁₀, gas occupy at STP? (List assumptions you made to answer this question.)