Question

Calculate the internal energy change for each of the following.
a.One hundred (100.) joules of work are required to compressa gas. At the same time, the gas releases 23 J of heat.
b.A piston is compressed from a volume of 8.30 L to 2.80 Lagainst a constant pressure of 1.90 atm. In the process, thereis a heat gain by the system of 350. J.
c.A piston expands against 1.00 atm of pressure from 11.2 Lto 29.1 L. In the process, 1037 J of heat is absorbed.

Answer 1

well this is a long problem we can first start off with do u understand what u are reading , and which one do u think it is

Answer 2

change in internal energy = Q - W

positive Q = adding heat to the system
negative Q = removing heat from the system
positive W = work done on the system
negative W = work done by the system

a) in this case, 100J of work is being done on the system, while 23J is being released (a.k.a removed, a.k.a subtracted) from the system

b) for adiabatic (constant pressure) systems, work = -P * deltaV, where P is the pressure and deltaV is the change in volume. work is positive, since the gas is being compressed, and thus, work is being done on the system.

your work result will be in L * atm, which you can convert to joules by multiplying by 101.325 J

from there, the system gains 350J, so add 350J to the result

c) similar concept to b), but work is negative since the system is doing work.