Question

A balloon contains 25.0 grams helium (He) gas at room temperature (22 °C) and occupies a volume

of 75.0 L. How much pressure does the He gas exert on the walls of the balloon?

Answer 1

The pressure exerted by He on walls of balloon is 2.02 atm.

Step-by-step explanation:

Given data:

Mass of helium = 25.0 g

Temperature = 22°C

Volume of gas = 75.0 L

Pressure exert by the gas on walls of balloon = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

Now we will convert the temperature.

22+273 = 295 K

Now we will calculate the number of moles of He.

Number of moles = mass/ molar mass

Number of moles = 25 g/ 4 g/mol

Number of moles = 6.25 mol

Now we will put the values in formula.

P × 75.0 L = 6.25 mol × 0.0821 atm.L/mol.K ×295 K

P × 75.0 L = 151.372 atm.L

P = 151.372 atm.L / 75.0 L

P = 2.02 atm

The pressure exerted by He on walls of balloon is 2.02 atm.