Consider the following reaction equation:
\(2SO_3(g) → 2SO_2(g) + O_2\)(g)
∆H = +198 kJ/mol
Which of the following statements about the reaction is correct?
- 198 kJ of energy is given off
- The reaction is exothermic
- The reaction container would feel warm.
-
198 kJ of energy is absorbed
The correct answer is: D
Explanation
A positive value of ∆H (+198 kJ mol^-1) indicates that the reaction is endothermic, meaning it requires an input of energy to proceed. In this case, the reaction absorbs 198 kJ of energy per mole of reactants to convert 2 moles of \(SO_3\) into 2 moles of \(SO_2\) and 1 mole of \(O_2\). This means that the reaction container would need to be supplied with energy, and it would feel cooler rather than warmer.