Using the equations and enthalpy values provided, which mathematical expression can be used to determine the unknown enthalpy change represented by x?

3C + 3O2 yields 3CO2 deltaH = - 1182 kJ

4H2 + 2O2 yields 4H2O deltaH = - 1144 kJ

C3H8 + 5O2 yields 3CO2 + 4H2O deltaH = x

3H8 3C + 4H2 H = 104 kJ

A. 104 = (-1182) - [x + (-1144) ]

B. 104 = x - [ (-1182) + (-1144) ]

C. 104 = (-1182) + (-1144) + x

D. 104 = x + (-1182) - (-1144)

Question

Hudson Cameron

Chemistry

24 March, 03:23

Using the equations and enthalpy values provided, which mathematical expression can be used to determine the unknown enthalpy change represented by x?

3C + 3O2 yields 3CO2 deltaH = - 1182 kJ

4H2 + 2O2 yields 4H2O deltaH = - 1144 kJ

C3H8 + 5O2 yields 3CO2 + 4H2O deltaH = x

3H8 3C + 4H2 H = 104 kJ

A. 104 = (-1182) - [x + (-1144) ]

B. 104 = x - [ (-1182) + (-1144) ]

C. 104 = (-1182) + (-1144) + x

D. 104 = x + (-1182) - (-1144)

+1

Answers (1)

Know the Answer?

Edith Huang · Answer 1

In order to solve this, we need to make use of Hess' Law.

We are already given the equations and their corresponding deltaH. Using Hess' Law, we can generate this equation:

104 kJ = x - (-1182 kJ) - (-1144 kJ)

Among the choices, the answer is

B. 104 = x - [ (-1182) + (-1144) ]