Why heat is absorbed when ice melts into water, but when when dry ice melts into liquid CO2, heat is released?

2 ⤊

Why heat is absorbed when ice melts into water, but when when dry ice melts into liquid CO2, heat is released?

2007-08-21 22:12:16 · 3 answers · asked by teokz2002 1 in Science & Mathematics ➔ Chemistry

3 answers

melting is always endothermic at constant pressure, in order to prepare liquid CO2 you need to apply a pressure higher than atmospherical, otherwise the CO2 will sublimate.

2007-08-21 22:47:03 · answer #1 · answered by scientific_boy3434 5 · 0⤊ 0⤋

Melting is always endothermic, and freezing is always exothermic - with CO2 or water.

2007-08-21 22:34:19 · answer #2 · answered by Gervald F 7 · 2⤊ 0⤋

Liquid c02 is colder than dry ice.
Liquid h2o is warmer than regular ice.

2007-08-21 22:18:38 · answer #3 · answered by Anonymous · 0⤊ 2⤋