Use values of standard enthalpies of formation to calculate the enthalpy change for the reaction below:

Question

Use values of standard enthalpies of formation to calculate the enthalpy change for the reaction below: 

CO(g)+2H2(g)→ CH3OH(l)

Give the quantity (rounded to the nearest whole number) and unit (kJ) and don't forget the + or - sign. 

Answer 1

You want to look up the standard enthalpy of formation of each reactant and product. The ∆Hformation for H2 will be zero, but find ∆Hformation for CH3OH(l) and subtract it from the ∆Hformation for CO(g) and that will give you the answer. The general formula for this is...

∑n∆H_{formation products} - ∑∆H_{formation reactants} = ∆H_reaction