When a cylinder of helium gas is left standing in the sun, the temperature of the helium reaches 31.5C. The cylinder has a volume of 60.0 L and contains 0.020 mol of helium. What is the pressure in atmospheres inside the cylinder? What is the value for R for this problem?

The pressure inside the cylinder is atmospheres.

The value for R for this problem is 0.082 atmosphere-liters per mol-Kelvin.

Explanation:

Let suppose that helium gas inside the cylinder behaves as an ideal gas, the equation of state for the ideal gas is:

(1)

Where:

- Pressure, measured in atmospheres.

- Volume, measured in liters.

- Molar quantity, measured in moles.

- Temperature, measured in Kelvin.

- Ideal gas, measured in atmosphere-liters per mole-Kelvin.

If we know that , , and , then the pressured inside the cylinder is:

The pressure inside the cylinder is atmospheres.

The value for R for this problem is 0.082 atmosphere-liters per mol-Kelvin.