Part A For which of the following reactions is H rxn equal to H f of the product

ID: 549579 • Letter: P

Question

Part A

For which of the following reactions is Hrxn equal to Hf of the product(s)?

You do not need to look up any values to answer this question.

Check all that apply.

Hints

Check all that apply.

Part B

The combustion of propane, C3H8, occurs via the reaction

C3H8(g)+5O2(g)3CO2(g)+4H2O(g)

with heat of formation values given by the following table:

Calculate the enthalpy for the combustion of 1 mole of propane.

Express your answer to four significant figures and include the appropriate units.

S(s)+O2(g)SO2(g) Li(s)+12F2(g)LiF(s) SO(g)+12O2(g)SO2(g) SO3(g)12O2(g)+SO2(g) 2Li(s)+F2(g)2LiF(s) Li(s)+12F2(l)LiF(s)

Part A: enthalpy of reactions = formation enthalpy of products - formation enthalpy of reactants

criteria: enthalpy of formation of any element (solid, liquid, gas state) is zero

so, enthalpy of reactions = formation enthalpy of products for following reactions

Li(s)+12F2(l)LiF(s)

Part B:

enthalpy of combustion = formation enthalpy of products - formation enthalpy of reactants

= [3*(393.5) + 4*(241.8) - (-104.7 + 0) ] kj/mole

= - 2043 kj/mole

S(s)+O2(g)SO2(g) Li(s)+12F2(g)LiF(s)