How many moles of a gas occupy a volume of 5.0 L and exhibit a pressure of 775 torr at 25 ° C?

Question

Quizplus · Accepted Answer

To solve this, use the ideal gas law: PV = nRT, where P is pressure in atmospheres, V is volume in liters, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is temperature in Kelvin. First, convert the given pressure from torr to atmospheres (1 atm = 760 torr), so 775 torr = 775/760 atm. Convert the temperature from Celsius to Kelvin by adding 273.15, so 25 °C = 298.15 K. Plugging in the values: (775/760 atm) * 5.0 L = n * 0.0821 L·atm/(mol·K) * 298.15 K. Solving for n gives approximately 0.21 moles.

How Many Moles of a Gas Occupy a Volume of 5.0