Hope this helps!! You were correct for Question 9 but incorrect for Question 10. Yes, the value comes out to be 62.4 kJ but watch out for your signs! It is definitely a positive number. Therefore, you have to consider your other choices. When I converted the 62.4 kJ to J, I found an option that matches my answer.
Nonmetal oxides react with water to form oxyacids. Ex. CO2 + H2O → H2CO3 Page 3 Decomposition - compound (reactant) breaks down into 2 or more simpler substances.