V work) on the surroundings that is equal When a gas is heated, it absorbs 175 j
ID: 555480 • Letter: V
Question
V work) on the surroundings that is equal When a gas is heated, it absorbs 175 joules of heat from the to 309 joules. (a) Determine whether the amounts of heat (a) and work (w) exchanged should have positive or negative signs. heat (4) O positive O negative work (w) O positive O negative (b) Calcuilate the change in internal energy (4E) of the gas (c) Determine whether one or more of the following is a state function: internal energy (E) of a system, change in internal energy (AE) of a system, heat (a) absorbed or released by a system, work (w) done on or by a system. (Select all that apply,) internal energy (E) of a system change in internal energy (AE) of a system heat (g) absorbed or released by a system work (w) done on or by a systemExplanation / Answer
a) Heat is absorbed by the system, i.e, heat moves into the system. Therefore, q > 0 and hence the sign of the heat (q) is positive (ans).
Work is done by the system in expansion, i.e, the gas does work; hence the sign of work (w) is negative (ans).
b) The internal energy (E) of a system is given as
E = q + w
We have q = -175 J and w = -309 J (remember work is done by the system on the surroundings); hence,
E = (175 J) + (-309 J) = -134 J (ans).
c) A state function is defined as a thermodynamic quantity that depends only on the state of the system. A state function is independent of the path of a thermodynamic transformation. A state function has a unique value at each state of the system and is not affected by the path taken by the system to reach that state. The internal energy (E) and the change in internal energy (E) of the system are state functions (ans). Heat and work are path functions.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.