# Blog

## What is the formula for calculating the PV value? ## How do you find the PV of a gas system?

• PV = nRT. V = n * (RT/P) V = constant * n. V n (Avogadro's law) A very common situation is that P, V and T are changing for a fixed quantity of gas . PV = nRT. (PV)/T = nR = constant. Under this situation, (PV/T) is a constant, thus we can compare the system before and after the changes in P, V and/or T: . Example: .

## How do you find the unknown variable in the equation PV nRT?

• The Ideal Gas Law Calculator finds the unknown variable in the equation PV = nRT when three of the variables are known. The ideal gas law formula states that pressure multiplied by volume is equal to moles times the universal gas constant times temperature.

## What are the units of energy for the gas constant PV?

• PVcan have the units of energy: Therefore, Rcan include energy units such as Joulesor calories Values for the gas constant R Units Value L atm/mol K 0.08206 cal/mol K 1.987 J/mol K 8.314 m3Pa/mol K 8.314 L torr/mol K 62.36 Example: If we had 1.0 mol of gas at 1.0 atm of pressure at 0°C (273.15 K), what would be the volume? PV = nRT V = nRT/P  