Liquid go to solid heat gain or heat loss?

Answer 1

When something goes from it's liquid form to solid, it is a heat loss. A simple example is making an ice-pop in a freezer. The liquid fruit-juice/water mixture has to lose heat to the freezer (and the other contents) in order to solidify. Subsequently it has to gain heat from your mouth to melt when you eat it (which is why it feels cold).

Answer 2

No. When a gas condenses to a liquid it will release (or loose) a form of heat called "latent heat". This heat (energy) is required to break the intermolecular bonds and will not raise the temperature of the substance, but will retain the energy as heat.

More simply, steam at 100 degrees C is "hotter" (contains more energy) than water at 100 degrees C.

Looking at it the other way around - from liquid to gas makes everything clear: When you boil water, you put in 1 calorie of heat energy and 1 ml of water goes up by 1 degree C. This goes on, with your test tube constantly having the temperature change for the better. Then we reach 100 degrees (water boiling point). Now we put in more heat, but the temperature stays put. Instead, the water turns to vapor.

Having said this, perhaps it would help to clarify what "gaining heat" is. There are two ways of looking at the question: Intuitively, the way we perceive it, and scientifically, which is probably what this question is about.

First: Intuitively - If the liquid "gained heat" - either it's temperature would be higher (as shown by a thermometer inserted in the liquid), or the surrounding temperature would go down (in order to give energy to the liquid, so now the surroundings lost some energy which the new liquid gained). But neither happen. Rather, JUST THE OPPOSITE happens:

The liquid "LOOSES HEAT" - but it's temperature does not go down. The surrounding temperature goes UP! In order to explain this intuitively, I like to think of a sponge. Liquid is the sponge all squished, while the gas is a free sponge, ready to absorb (heat).

When the sponge is squished, the heat leaves it.

Now to the scientific perception: In science you don't look at things as "pushing" or "causing". You look at the numbers before and after, and say: So and so is what "happened". So your not looking at the "squishing" but rather just checking things at the different stages. When it was gas: Its temperature was A, and the surroundings were B. Now the liquid's temperature is still the same, but the gas around it heated up.

Answer 3

You gain heat.