Question

C2H2(g) + 2H2(g) --> C2H6(g)

Information about the substances involved in the reaction represented above is summarized in the following table:

C2H2(g) 226.7 kj/mol
C2H6(g) -84.7 kj/mol
[the values are the change in enthalpy]

a. write the equation for the heat formation of C2H6.
b. Use the above information to determine the enthalpy of reaction for the equation given.

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A, for some reason, is throwing me off. I don't know what it's asking. Help?

Thanks!

Answer 1

Do part b first.
delta Hrxn = (delta H products) - (delta H reactants)

Then write the equation and add heat to the left side or to the right side depending upon the sign of delta Hrxn. I think that will be negative; therefore,
C2H2(g) + 2H2(g) --> C2H6(g) + heat