# How do you calculate the ideal gas law constant?

How do you calculate the ideal gas law constant?

You do an experiment in which you measure the values of P,V,n, and T, and then you insert these values into the Ideal Gas Law.

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯aaPV=nRTaa−−−−−−−−−−−−−

You do an experiment in which you measure the values of P, V, n, and T, and then you insert these values into the Ideal Gas Law.

#### Explanation:

The Ideal Gas Law iscolor(blue)(bar(ul(|color(white)(a/a)PV=nRTcolor(white)(a/a)|))) where R is the Universal Gas Constant.We can rearrange this to getR = (PV)/(nT)The units of R depend on the units you use for P and V.For example, repeated experiments show that at standard temperature and pressure (STP) — 273.15 K and 1 bar — 1 mol of gas occupies 22.711 L.You can use this information to evaluate R.R = (PV)/(nT) = (1 bar ×22.711 L)/(1 mol × 273.15 K) = 0.083 14 bar·L·K^-1mol^-1If the pressure is measured in kilopascals (1 bar = 100 kPa), you calculateR = (PV)/(nT) = (100 kPa × 22.711 L)/(1 mol × 273.15 K) = 8.314 kPa·L·K^-1mol^-1If you use strictly SI units, then pressure is measured in pascals and volume is measured in cubic metres.R = (PV)/(nT) = (100 × 10^3 color(white)(l)Pa × 22.711 × 10^-3 color(white)(l)m^3)/(1 mol × 273.15 K) = 8.314 Pa·m^3K^-1mol^-1Always use the value of R that corresponds to the units that you are using for P and V.