Two substances each have a temperature of 23 degrees Celcius. After they are combined the temperature rises to 27 degrees Celcius. What evidence proves a chemical reaction occurred?

Asolution is made by dissolving 25.5 grams of glucose (c6h12o6) in 398 grams of water. what is the freezing point depression of the solvent if the freezing point constant is -1.86 °c/m? show all of the work needed to solve this problem.

In a water molecule, hydrogen and oxygen are held together by a(an) bond. a) double covalent b) ionic c) nonpolar covalent d) hydrogen e) polar covalent

40dm3 of gas at 760 torr are heated from 5°c to 50°c what is the new volume