Import Question JSON

$\text{Hint: In the formation reaction energy always release.}$ $\text{Step 1:}$ $\text{The standard enthalpy change for the formation of one mole of a compound from its elements in their most stable states of aggregation (also known as reference states) is called Standard Molar Enthalpy of Formation.}$ $\text{By convention, the enthalpy of elements in their standard states is taken as zero. This provides a reference point for measuring enthalpy changes.}$ $\text{Step 2:}$ $\text{When we examine formation reactions for different compounds, we find that most compounds have negative enthalpies of formation. This means that energy is released (exothermic reaction) when these compounds are formed from their constituent elements.}$ $\text{For example:}$ $\text{C(s)} + \text{O}_2\text{(g)} \rightarrow \text{CO}_2\text{(g)} \quad \Delta_f\text{H}^{\circ} = -393.5 \text{ kJ/mol}$ $\text{H}_2\text{(g)} + \frac{1}{2}\text{O}_2\text{(g)} \rightarrow \text{H}_2\text{O(l)} \quad \Delta_f\text{H}^{\circ} = -285.8 \text{ kJ/mol}$ $\text{Step 3:}$ $\text{However, not all compounds have negative enthalpies of formation. Some compounds have positive enthalpies of formation, meaning energy is absorbed (endothermic reaction) when these compounds are formed.}$ $\text{Examples include:}$ $\text{C(s)} + 2\text{H}_2\text{(g)} \rightarrow \text{CH}_4\text{(g)} \quad \Delta_f\text{H}^{\circ} = +74.8 \text{ kJ/mol}$ $\text{N}_2\text{(g)} + \text{O}_2\text{(g)} \rightarrow 2\text{NO(g)} \quad \Delta_f\text{H}^{\circ} = +90.2 \text{ kJ/mol}$ $\text{Therefore, while many compounds have negative enthalpies of formation, this is not universally true for all compounds. The correct statement is that the enthalpy of formation of compounds is generally negative, but there are exceptions.}$ $\text{Note: There is an error in the hint provided in the image. It states that 'In the formation reaction energy always release' and 'The enthalpy of formation is always negative'. This is incorrect as demonstrated by the examples of compounds with positive enthalpies of formation.}$ $\text{The correct answer is option 1: Generally negative.}$