Question

1. When the temperature of a rigid hollow sphere containing 685 L of helium gas is

held at 621 K, the pressure of the gas is 189 x 10 kPa. How many moles of
helium does the sphere contain?​

Answer 1

250.756 moles He

Step-by-step explanation:

From the question we are given;

Volume, L = 685 L

Temperature, T = 621 K

Pressure, P = 189 × 10 kPa

We are required to calculate the number of moles of the gas,

Using the Ideal gas equation,

PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.

We can replace the known variables and constant in the equation to get the unknown variable, n.

Using ideal gas constant as 8.3145 L.kPa/K/mol

`n=(PV)/(RT)`

`n=((1890)(685))/((8.3145)(621))`

`n = 250.7557 moles`

n = 250.756 moles

The moles of helium contained in the sphere is 250.756 moles