Calculate internal temperature and energy changes

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Pochen Liu
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Homework Statement
Calculate internal temperature and energy changes
Relevant Equations
pV = nRT
Equation ΔU = Q + W, the first law of thermodynamics written with change in internal energy on the left and heat plus work on the right.
Ideal gas law equation written as pV = nRT.
Question

Online homework problem screenshot, Chapter 19 Problem 084: ideal gas with 3.80 mol, states 1 to 3 with pressures and volumes given in terms of p1 and V1, asking temperatures in states 1 and 2 and net change in internal energy, with entered answers 145.7268 K and -134.1779 K and an empty third answer field.

(These are incorrect values)

Attempt
I used
Ideal gas law equation written as pV = nRT.
and then found the respective change in temperature.

However for the last question I have no idea, do I sum up the net change in temperature and use
Thermodynamics equation ΔU = Q + W, the first law of thermodynamics, with change in internal energy equal to heat added plus work done on the system.

But then what is the work and how do we figure it out?
 
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Your answers to question a and b are incorrect. Please show your work.

Regarding question c, True of False:

1. The change in internal energy between two thermodynamic equilibrium states of a pure substance is a function only of the temperature, pressure, and volume of the substance in those two states.

2. If the temperature, pressure, and volume of a substance in the two states is known, the process path between these two states (as characterized by Q and W) is irrelevant to determining the change in internal energy.

3. For a given amount of an ideal gas, its internal energy depends only on its temperature (and not pressure or volume).
 
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