Question

PLEASE HELP ME

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.
H2(g)+12O2(g)→H2O(g)
Li(s)+12F2(g)→LiF(s)
2Li(s)+F2(g)→2LiF(s)
Li(s)+12F2(l)→LiF(s)
2H2(g)+O2(g)→2H2O(g)
H2O2(g)→12O2(g)+H2O(g)

Answer 1

Step-by-step explanation:

Li(s)+1/2 F₂(g)→LiF(s)

In this reaction one mole of product is formed from gaseous state of reactants . So this reaction will represent the reaction for which ΔH∘rxn equals to ΔH∘f .

In other reaction one mole is not produced if we balance the reaction. The reactant must be in gaseous state . ΔH∘f . represents heat of formation . ΔH∘rxn represents heat of reaction .