Does the temperature of a substance vary while its melting/freezing? Explain.
5 answers
I think so
Probably so
Definitely NOT. Look it up on Google. For example, melting ice. Start at -5 C. Heat must be added and the temperature of the ice cube will increase until the internal temperature reaches 0 C. At that point the ice crystal bonds begin to break and the first drop of liquid water forms. As more heat is added, the temperature of the water previously formed CAN'T increase because that heat is being used to break more of the crystal structure of the ice. That will continue and the temperature of the liquid water formed will stay at 0 C. Finally, when all of the ice crystal has changed to liquid water, then, and only then, will the temperature start to climb as more heat is added. That will continue until the temperature of the liquid water reaches the next phase change; i.e., at the boiling point of 100 C. Then the same thing happens; i.e., the energy being added by increasing the literature goes to vaporizing the water molecules. That is the liquid water molecules take energy to break out of the liquid state and become gaseous H2O (steam). The temperature of a pot of boiling water will not increase (assuming the air pressure remains constant) until ALL of the water has been vaporized and the boiling pot is empty. Of course the temperature of the boiling water is 100 C and the temperature of the steam is 100 C. You CAN make superheated steam but not without changing the pressure. By the way, a burn from steam is worse than a burn from boiling water even though both are at 100 C. Yes, I know, a burn from either is something we don't play around with. Why is a steam burn worse? Boiling water has a temperature of 100 C and that's bad enough. But steam @ 100 C must give up it's heat of vaporization (the heat needed to turn it from liquid water to steam) FIRST so it burns the skin while changing from steam to liquid water THEN it burns just as boiling water would burn. This may be more than you ever wanted to know about the subject but it's complete. Welcome to the world of science.
Oh dang I’m sorry.
My older sister was here and said it did. She’s a liar lol. Sorry Jenna.