A 4.00-liter container is divided into two equal parts, one part containing 0.0100 mole of neon, and the other part containing 0.0100 mole of helium. The divider is removed and the gases mix. What is the change in entropy (in J/K) of this system?
A) 0.057 6
B) 0.115
C) 0.173
D) 0.086 4
E) 0.144

Question

Quizplus · Accepted Answer

The change in entropy for mixing two ideal gases can be calculated using the formula ΔS = -nR[ xln(x) + yln(y) ], where n is the total moles of gas, R is the gas constant (8.314 J/mol·K), and x and y are the mole fractions of the two gases. Since both gases have the same amount, x = y = 0.5. The total moles n = 0.0200 moles. Plugging these values into the formula gives ΔS = 0.115 J/K.

A 400-Liter Container Is Divided into Two Equal Parts, One Part