How do you calculate the molar volume of a gas at STP?

The molar volume of a gas at Standard Temperature and Pressure (STP) can be calculated using the ideal gas law, which is represented by the equation:

PV = nRT

Where:

P is the pressure (in atmospheres, atm)
V is the volume (in liters, L)
n is the number of moles of the gas (in moles, mol)
R is the ideal gas constant (approximately 0.0821 L·atm/(mol·K) when using these units)
T is the temperature (in kelvin, K)
At STP, the conditions are defined as:

Pressure (P) = 1 atmosphere (atm)
Temperature (T) = 273.15 kelvin (K)
Now, you want to calculate the molar volume (V) at STP, so you'll rearrange the ideal gas law to solve for V:

V = (nRT) / P

Substituting the values for P and T at STP:

V = (n * 0.0821 L·atm/(mol·K) * 273.15 K) / 1 atm

V = (n * 22.414 L/mol)

So, the molar volume of a gas at STP is approximately 22.414 liters per mole (L/mol). This is a useful constant to remember when working with gases at standard conditions.