Question

I will rate life saver to anyone who can answer these short questions for me!

1. Provide a molecular/microscopic interpretation of heat flow or heating, and work.

2. Explain why U of an ideal gas is only dependent on T, and independent on V and P, and show that CP - CV = nR for an ideal gas.

3. When 229 J of energy is supplied as heat at constant pressure to 3.00 mol CO2(g), the temperature of the sample increases by 2.06 K. Calculate the molar heat capacities at constant volume and constant pressure of the gas.

Answer 1

Heat is energy (q) in transit and always transfers from a body at high temperature to another body at lower temperature. The microscopic energy of an object is represented as internal energy, the energy of molecules making up the substance. Internal energy of a body increases when heat is transferred to it and this is referred to as heating.

From first law of thermodynamics, we can write

Change in internal energy= q+W

Where q= heat added and W = work done

For a adiabatic system q=0   Change in internal energy= W

Energy of the system changes due to changes in external variables