Question

CHEM 1211L Lab Manual - Page 122 Air Bag Page 1 Pre-Lab Questions Name: Write the mathematical expression for the ideal Gas Law. Identify each symbol and constant used. Calculate the volume of 20.0 g of oxygen at 25°C and one atmosphere of pressure qur NaNo(s);

Chem 1211 Air Bag Prelab

Chem 1211 Pre-Lab Air Bag

Answer 1

1. The mathematical expression for the ideal gas law is

PV = nRT

where P = Pressure of the gas

V = Volume of the gas

n = Number of moles of the gas

R = Universal gas constant

T = Temperature of the gas

The ideal gases are those gases which obeys gas laws at all temperatures and pressures. All the ideal gases follow this ideal gas equation at all temperatures and pressures.

2. The required volume of oxygen can be calculated from the ideal gas equation PV = nRT by considering oxygen as an ideal gas.

Given that the temperature is 20^oC = 20 + 273 K = 293 K ( ^oC = (^oC + 273) K)

Pressure = 1 atm

We have the value of universal gas constant R = 0.0826 L.atm/mol.K

Weight of oxygen = 20 grams.

We have molar mass of oxygen = 16 g/mol

Therefore the number of moles of oxygen = Weight / Molar mass = 20 g / 16 g/mol = 1.25 moles

Therefore from the ideal gas equation

PV = nRT

Volume V = nRT / P = 1.25 mol x 0.0826 L.atm/mol.K x 293 K / 1 atm = 30.25225 Litres.

Therefore the required volume of oxygen is 30.25225 Litres.