Question

S(s) + O2(g) → SO2(g) =x
2SO3(g) →2SO2(g) + O2(g)=y
Based on the information in the table above, which of the following expressions is equivalent to AH for the reaction represented below?
2S(s) + 3O2(g) → 2SO3(g)
Choose 1 answer:
a)x + y
B)x- y
c)x+y\2
D)2x-y

Answer 1

The enthalpy change for a reaction can be determined by summing the enthalpy changes of the individual reactions that make up the overall reaction.

For the reaction 2S(s) + 3O2(g) → 2SO3(g), we can use the given equations:

1) S(s) + O2(g) → SO2(g)

2) 2SO3(g) → 2SO2(g) + O2(g)

To get the equation above, we need to reverse equation 1 and double equation 2:

1) SO2(g) → S(s) + O2(g)

2) 2SO2(g) + O2(g) → 2SO3(g)

Now, we can use these modified equations to calculate the enthalpy change:

Enthalpy change for the overall reaction = Enthalpy change for equation 2 - Enthalpy change for equation 1

= y - x

Therefore, the answer is B) x - y.