A helium balloon has a volume of 2.5 L. When heated to 343.5K the pressure of the gas is 66.7 kPa. How many moles of He gas would there be?

0.06mole

Explanation:

Given parameters:

Volume of balloon = 2.5L

T = 343.5K

P = 66.7kPa; in atm gives = 0.66atm

Unknown:

Number of moles of He = ?

Solution:

To solve this problem, we use the ideal gas equation.

It is mathematically expressed as;

Pv = nRT

where p is the pressure

v is the volume

n is the number of moles

R is the gas constant

T is the temperature

0.66 x 2.5 = n x 0.082 x 343.5

n = 0.06mole