What is the volume occupied by one mole of helium at 0°C and 1 atm pressure?

The volume occupied by one mole of any gas at 0°C (273.15 K) and 1 atm pressure is given by the ideal gas law, which states that the volume of a gas is directly proportional to the number of moles of the gas and the temperature, and inversely proportional to the pressure.

The ideal gas law is usually stated as PV = nRT, where:

• P is the pressure of the gas,
• V is the volume of the gas,
• n is the number of moles of the gas,
• R is the ideal gas constant, and
• T is the temperature of the gas (measured in Kelvin).

At 0°C and 1 atm pressure, the ideal gas constant R is usually given as 0.0821 L·atm/(K·mol).

So, if we want to find the volume V occupied by one mole of helium (or any gas) at these conditions, we can rearrange the ideal gas law to solve for V:

V = nRT / P

Substituting the given values into this equation gives:

V = (1 mol)(0.0821 L·atm/(K·mol))(273.15 K) / 1 atm = 22.4 L

So, one mole of helium occupies 22.4 liters at 0°C and 1 atm pressure.