Question

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

Answer 1

Answer:

0.482 ×10²³ molecules

Explanation:

Given data:

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