Question

The temperature of 2.75 mol of an ideal gas is changed from 95.0 degrees C to 15.0 degrees C at constant pressure. Cv,m = 3R/2. Clculate q, w, delta U, and delta H.

Answer 1

The question involves calculating heat, work, change in internal energy, and change in enthalpy for an ideal gas being cooled at constant pressure. To find these values, we will use the given heat capacity and formulas that relate these quantities for ideal gases.

Step-by-step explanation:

The student is asking to calculate the heat q, work w, change in internal energy ΔU, and change in enthalpy ΔH for an ideal gas that is being cooled at constant pressure. Given that the molar heat capacity at constant volume, Cv,m, is equal to 3R/2, we use the following relationships:

• Change in internal energy, ΔU = nCv,mΔT
• Heat added or removed, q = nCp,mΔT = n(Cv,m + R)ΔT
• Work done, w = -PΔV = -nRΔT (since it's at constant pressure)
• Change in enthalpy, ΔH = q (at constant pressure)

To calculate the values, one needs to convert temperatures from Celsius to Kelvin by adding 273.15, use the gas constant R (which is 8.314 J/(mol·K)), and then substitute the values into the equations above.