Methanol (CH3OH) is an organic solvent and is also used as a fuel in some automobile engines. From the following data, calculate the standard enthalpy of formation of methanol. ( 2CH3OH(l) +  3O2(g)  →  2CO2(g)  +  4H2O(l)     ΔHorxn = –1452.8 kJ/mol

A 0.470-g sample of magnesium reacts with 200 g dilute HCl in a coffee-cup calorimeter to form MgCl2(aq) and H2(g). The temperature increases by 10.9 C as the magnesium reacts. Assume that the mixture has the same specific heat as water and a mass of 200 g. (a) Calculate the enthalpy change for the reaction. Is the process exothermic or endothermic? (b) Write the chemical equation and evaluate H.

The thermochemical equation for the burning of methane, the main component of natural gas, is CH4(g)+2O2(g)CO2(g)+2H2O(l)H=890kJ (a) Is this reaction endothermic or exothermic? (b) What quantities of reactants and products are assumed if H = 890 kJ? (c) What is the enthalpy change when 1.00 g methane burns in an excess of oxygen?

Compounds with carboncarbon double bonds, such as ethylene, C2H4, add hydrogen in a reaction called hydrogenation. C2H4(g)+H2(g)C2H6(g) Calculate the enthalpy change for this reaction, using the following combustion data: C2H4(g)+3O2(g)2CO2(g)+2H2O(l);H=1411kJC2H6(g)+72O2(g)2CO2(g)+3H2O(l);H=1560kJH2(g)+12O2(g)H2O(l);H=286kJ