Using the equations
H2 (g) + F2 (g) → 2 HF (9) AH° = -79.2 kJ/mol
C(s) + 2 F2 (g) CF, (g) AH° = 141.3 kJ/mol
Determine the enthalpy for the reaction
C(s) + 4 HF (g) - CF. (g) + 2 H2 (g).

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

Show how to convert the temperature 84.7° c to kelvin. include all steps and label the final answer.