Question

Part A 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. Check all that apply. 1)Li(s)+12F2(l)→LiF(s)

.2) SO3(g)→12O2(g)+SO2(g).

3) SO(g)+12O2(g)→SO2(g)

. 4) 2Li(s)+F2(g)→2LiF(s).

5)S(s)+O2(g)→SO2(g)

.6) Li(s)+12F2(g)→LiF(s)

Answer 1

answer :

S(s) + O2(g) ------------> SO2(g)

Li(s) + 1/2 F2(g)----------> LiF(s)

Explanation :

The standard enthalpy of formation is defined as the change in enthalpy when one mole of a substance in the standard state (1 atm of pressure and 298.15 K) is formed from its pure elements under the same conditions.

remaing all are not :

ΔH∘rxn = ΔH∘f products - ΔH∘f reactants.

for above two reactions :

ΔH∘rxn = ΔH∘f products. because enthalpyof elemental state of S and F2 and Li are zero.