To determine the standard heat of reaction, ΔHrxn°, let's apply the Hess' Law.
ΔHrxn° = ∑(ν×ΔHf° of products) - ∑(ν×ΔHf° of reactants)
where
ν si the stoichiometric coefficient of the substances in the reaction
ΔHf° is the standard heat of formation
The ΔHf° for the substances are the following:
CH₃OH(l) = -238.4 kJ/mol
CH₄(g) = -74.7 kJ/mol
O₂(g) = 0 kJ/mol
ΔHrxn° = (1 mol×-74.7 kJ/mol) - ∑(1 mol×-238.4 kJ/mol)
ΔHrxn° = +163.7 kJ
Hi, the temperature of water is not a physical characteristic because it does not tell us a lot about the substance.
Specificity. It’s really loose to say that something is fast, since speed can be scalarly linked and relative. I could say that both a car on the highway is fast, but so is the speed of light. The actual speed of something helps to do away with the arbitrary nature of using “fast” and “slow”; however, we’re still at step one of the person who is receiving the information is unfamiliar with the scale that the actual speed is defined in.
