How molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg?

0.482 * 10²³ molecules

Explanation:

Given dа ta:

Volume of gas = 2.5 L

Temperature of gas = 50°C (50+273 = 323 k)

Pressure of gas = 650 mmHg (650/760 = 0.86 atm)

Molecules of N₂=?

Solution:

PV = nRT

n = PV/RT

n = 0.86 atm * 2.5 L / 0.0821 atm. mol⁻¹. k⁻¹. L * 323 k

n = 2.15 atm. L / 26.52 atm. mol⁻¹. L

n = 0.08 mol

Number of moles of N₂ are 0.08 mol.

Number of molecules:

one mole = 6.022 * 10²³ molecules

0.08*6.022 * 10²³ = 0.482 * 10²³ molecules