A) The change in internal energy of the gas can be found using the equation:
ΔU = q - W
where ΔU is the change in internal energy, q is the heat added to the system, and W is the work done by the system.
Since the process is at a constant pressure, the work done by the system is given by:
W = PΔV
where P is the constant pressure and ΔV is the change in volume.
Since the volume is not given, we need to find it first. We can use the ideal gas law equation:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.
We can rearrange the equation to solve for V:
V = (nRT) / P
Plugging in the values,
V = (3.3 mol * 8.314 J/(mol*K) * T) / (120 kPa)
V = (3.3 mol * 8.314 J/(mol*K) * T) / (120,000 Pa)
Now we have the volume in terms of T, and we can substitute this into the equation for work done:
W = PΔV
W = (120 kPa) * [(3.3 mol * 8.314 J/(mol*K) * T) / (120,000 Pa)]
W = (120 * 10^3 N/m^2) * (3.3 mol * 8.314 J/(mol*K) * T) / (120 * 10^3 N/m^2)
W = 3.3 * 8.314 J/K * T
Now, we can substitute these values into the equation for ΔU:
ΔU = q - W
ΔU = 2100 J - (3.3 * 8.314 J/K * T)
B) To find the change in temperature, we can use the equation for heat:
q = nCΔT
where q is the heat added to the system, n is the number of moles, C is the molar heat capacity at constant pressure, and ΔT is the change in temperature.
Since argon is treated as an ideal monatomic gas, its molar heat capacity at constant pressure is given by:
C = (3/2)R
where R is the ideal gas constant.
Now we can substitute the values into the equation for heat:
2100 J = (3.3 mol) * ((3/2) * 8.314 J/(mol*K)) * ΔT
Simplifying,
2100 J = 3.3 * 3 * 8.314 J/K * ΔT
Solving for ΔT,
ΔT = 2100 J / (3.3 * 3 * 8.314 J/K)
C) To calculate the change in volume, we can use the equation:
ΔV = nRΔT / P
where ΔV is the change in volume, n is the number of moles, R is the ideal gas constant, ΔT is the change in temperature, and P is the pressure.
Now we can substitute the values into the equation:
ΔV = (3.3 mol * 8.314 J/(mol*K)) * ΔT / (120 kPa)
ΔV = (3.3 * 8.314 J/K) * ΔT / (120 * 10^3 N/m^2)