Question

For which of the following reactions is ΔH∘rxn equal to ΔH∘f 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.

2Li(s)+F2(g)→2LiF(s)

S(s)+O2(g)→SO2(g)

SO3(g)→12O2(g)+SO2(g)

Li(s)+12F2(l)→LiF(s)

SO(g)+12O2(g)→SO2(g)

Li(s)+12F2(g)→LiF(s)

Answer 1

for delta hf:

rule 1 : there must be 1 mol of product formed

rule 2: Reactant must be element in their standard state

option 1 is not correct

2 moles of product is formed. rule 1 fails

option 2 is correct

option 3 is not correct

1.5 moles of product is formed. rule 1 fails

option 4 is not correct

liquid is not standard state of F2. Standard state of F2 is gas. rule 2 fails

option 5 is not correct

SO is a compound and not an element. rule 2 fails

option 6 is correct

Answer: option 2,6