H₂ + ½ O₂ --> H₂O + 285 kJ

is an example of a(n)

C+ O₂ --> CO₂ + 60kJ

what is the ΔH for the reaction?

How do you calculate Enthalpy of a reaction?

Endothermic reactions feel

Did you hear about the man who got cooled to absolute zero?

Use the information below to determine the correct expression to calculate the enthalpy of formation of methane.
C(s)+O2(g)→CO2(g); ΔrH∘=−393.5kJ
2H2(g)+O2(g)→2H2O(l); ΔrH∘=−571.8kJ
CH4(g)+2O2(g)→CO2(g)+2H2O(l); ΔrH∘=−890.3kJ

(Hess's Law)Calculate the ∆H for the following reaction: 2H₂O₂ →  2H₂O  + 1 O₂ 
You are given these two equations:
2H₂  +  O₂ → 2H₂O            ∆H  =  -572 kJ
H₂  +  O₂  →  H₂O₂            ∆H  =  -188 kJ 

ΔH is the same thing as:

ΔH means:

A positive ΔH means the reaction is: