Duff states that equal masses of all substances have equal changes in internal energy when they have equal changes in temperature. Javan states that the change in internal energy is equal to a constant times the change in temperature for every ΔT, no matter how large or how small ΔT is, but that the constant is different for different substances. Which one, if either, is correct?
A) Neither, because the specific heat depends on the substance and may vary with temperature.
B) Neither, because a change of state may involve release or absorption of latent heat.
C) Neither because a substance may do work during a temperature change.
D) All of the statements above are correct.
E) Only statements (a) and (b) are correct.

Question

Quizplus · Accepted Answer

Duff's statement overlooks that the specific heat capacity, which determines how much energy is needed to change the temperature of a substance, varies between substances. Javan's statement is more accurate in that it acknowledges the role of specific heat capacity (the "constant" he refers to), but it simplifies the situation by not considering that specific heat can change with temperature and that phase changes can absorb or release energy without changing temperature. Additionally, when a substance does work or has work done on it during a temperature change, this also affects its internal energy independently of its temperature change. Therefore, all the statements provided offer important corrections or considerations to the initial claims.

Duff States That Equal Masses of All Substances Have Equal