Answer : The heat absorbed by the gas is closest to 34.9 kJ
Explanation :
First we have to calculate the moles of gas.
Using ideal gas equation:
where,
P = Pressure of gas = 70 kPa = 70000 Pa
V = Volume of gas =
n = number of moles = ?
R = Gas constant =
T = Temperature of gas =
Putting values in above equation, we get:
Heat released at constant volume is known as internal energy.
The formula used for change in internal energy of the gas is:
where,
= heat at constant volume = ?
= change in internal energy
n = number of moles of gas = 15.59 moles
= heat capacity at constant volume gas = 28.0 J/mol.K
= initial temperature = 350 K
= final temperature = 270 K
Now put all the given values in the above formula, we get:
Thus, the heat absorbed by the gas is closest to 34.9 kJ