Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1. What is the total kinetic energy of 0.5 mol of an ideal monatomic gas confine

ID: 701330 • Letter: 1

Question

1. What is the total kinetic energy of 0.5 mol of an ideal monatomic gas confined to 5.0 dm^3 at 150 kPa?

2. Compare the pressures predicted for 0.6 dm^3 of Cl2 weighing 18.5 g at 298.15 K using the ideal gas equation and the Van der Waals equation.

3. A sample of liquid acetone weighing 0.700 g was burned in a bomb calorimeter for which the heat capacity (including the sample) is 6937 J/K. The observed temperature rise was from 25.00 °C to 31.50°C. Calculate U and H for the combustion of 1 mol of acetone.

Explanation / Answer

Ans 1

Moles n = 0.5 mol

Volume V = 5 dm3

Pressure P = 150 kPa

From the concepts of Kinetic Theory of Gases

P = Nmu2 / 3V

Average Kinetic energy = 0.5 mu2

At constant pressure

V is proportional to n and Average Kinetic energy

N = n x L

From the above equations

PV = (2/3) x n x L x average kinetic energy

Total kinetic energy = L x average kinetic energy

PV = (2/3) x n x total kinetic energy

total kinetic energy = 1.5 PV/n

= 1.5 x 150 x 5 /0.5

= 2250 J/mol