Question

Calculate AH°rxn from AH°7 values (use table in textbook appendix) a) Cl2 (g) + 2 Na (s) -› 2 NaCl (s) EITHER -411.1kJ/mol b) 2 H2S (g) + 3 02 (g) -> 2 SO2 (g) + 2 H20 (g)

Answer 1

To find AH°rxn, we use the following equation:

What we're going to do is to sum the enthalpy of the products and then substract with the enthalpy of the reactives:

As you can see, we need to multiply by the coefficients of the reaction.

Now, just replace the values of the table:

So the answer is -822.2kJ/mol.

For b:

Now, just replace the values of the table:

The answer for b is -1036kJ/mol.