'x' g of molecular oxygen O₂ is mixed with 200 g of neon (Ne). The total pressure of the nonreactive mixture of O₂ and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of 'x' is_____. [Given: Molar mass of O₂=32gmol⁻¹. Molar mass of Ne=20gmol⁻¹J

Given:

• Total pressure, P_total = 25 bar
• Partial pressure of neon, P_Ne = 20 bar

P_O₂ = P_total - P_Ne

P_O₂ = 25 bar - 20 bar = 5 bar

The mole fraction (x_i) of a gas is given by:

x_i = P_i / P_total

For neon:

x_Ne = P_Ne / P_total = 20 / 25 = 0.8

For oxygen:

x_O₂ = P_O₂ / P_total = 5 / 25 = 0.2

The molar mass of neon (Ne) is 20 g/mol. Thus:

n_Ne = mass of Ne / molar mass of Ne

n_Ne = 200 g / 20 g/mol = 10 mol

Since the mole fraction of neon is 0.8:

n_total = n_Ne / x_Ne

n_total = 10 mol / 0.8 = 12.5 mol

n_O₂ = n_total × x_O₂

n_O₂ = 12.5 mol × 0.2 = 2.5 mol

The molar mass of oxygen (O₂) is 32 g/mol. Thus:

Mass of O₂ = n_O₂ × molar mass of O₂

Mass of O₂ = 2.5 mol × 32 g/mol = 80 g

Final Answer:

The mass of molecular oxygen in the mixture is 80 grams.