Question

Isothermal Work -- The work done BY the gas for an isothermal process is W=-40J. What is the heat for this process? (Careful: this is work done BY the gas).

a) 40J
b) -40J
c) 0J
d) not enough information given

Answer 1

The heat for the isothermal process where the work done by the gas is -40J is 40J, based on the first law of thermodynamics and the fact that for an isothermal process of an ideal gas, the change in internal energy is zero.

The correct answer is The correct answer is:b) -40J

Step-by-step explanation:

The work done by the gas in an isothermal process represents the amount of energy transferred from the gas to the surroundings.

According to the first law of thermodynamics, which states that ∆Eint = Q - W (where ∆Eint is the change in internal energy, Q is heat, and W is work done by the system),

if the process is isothermal for an ideal gas, the change in internal energy (∆Eint) is zero since the temperature is constant.

For an ideal gas under an isothermal process, Q (heat added to the system) is equal to the work done by the gas, but with an opposite sign.

Therefore, if the work done by the gas is -40J, the heat for this process is 40J, which is the energy transferred to the gas from the surroundings.

The correct answer is The correct answer is:b) -40J

Answer 2

For an isothermal expansion where the work done by the gas is W = -40J, the heat Q absorbed by the gas is 40J, according to the first law of thermodynamics.

Step-by-step explanation:

The work done by the gas in an isothermal process is given as W = -40J. According to the first law of thermodynamics, which states that the change in the internal energy of the system (ΔEint) is equal to the heat added to the system (Q) minus the work done by the system (W), we have ΔEint = Q - W. For an isothermal process involving an ideal gas, the change in internal energy (ΔEint) is zero since temperature and hence internal energy remains constant (since internal energy of an ideal gas only depends on temperature). Thus, the equation simplifies to 0 = Q - (-40J), which means that Q = 40J. Therefore, the heat for this process, representing the amount of heat absorbed by the gas, is 40J.