Question

Hello, I been starring at this question for two days now can anyone help. see below:

Calculate the standard entry change for the reaction.

C8H18 (I) + 25O2 (g) -> 8CO (g) + 9H20 (I)
ΔHrxn = ?

Given:
2C8H18 (I) + 25O2 (g) -> 16CO2 (g) + 18H20 (I)
ΔH = -11,020 kj

2CO (g) O2 (g) -> 2CO2 (g)
ΔH = -566.0 kj

Answer 1

The point is to achieve: \(C_8H_{18~ (l)} + 25~O_{2~(g)} -> 8~CO_{ (g)} + 9~H_2O (l)\)

from the other two equations.

That is, you add the two equations and the net result is the equation above.

The operations you apply to the equation will need to be applied to the changes in enthalpy as well.

Answer 2

Here are some examples: https://www.chem.tamu.edu/class/majors/tutorialnotefiles/enthalpy.htm

Answer 3

@aaronq than you!