How many molecules of CH4 are present in a 1.00L flask at 300K and 4.00 atm?

0.964× 10²³ molecules

Explanation:

Given data:

Number of molecules of CH₄ = ?

Volume = 1.00 L

Temperature = 300 K

Pressure = 4.00 atm

Solution:

First of all we will calculate the number of moles of CH₄ from ideal gas equation.

PV = nRT

n = PV/RT

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

n = 4.00 atm× 1.00 L  /  0.0821 atm. L/mol.K × 300 k

n = 4.00 atm.L / 24.63  atm. L/mol

n = 0.16 mol

Now we will determine the number of molecules by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole of CH₄ = 6.022 × 10²³ molecules of CH₄

0.16 mol  ×  6.022 × 10²³ molecules  / 1 mol

0.964× 10²³ molecules