Question:medium

The enthalpy of formation of hydrogen chloride (HCl) is \( -92.3 \, \text{kJ/mol} \). If 2 moles of HCl are formed from hydrogen and chlorine gas, calculate the total heat released.

Show Hint

The enthalpy of formation is always given for the formation of 1 mole of a substance. When more than 1 mole is formed, multiply the enthalpy of formation by the number of moles.
Updated On: Mar 28, 2026
  • \( -184.6 \, \text{kJ} \)
  • \( -92.3 \, \text{kJ} \)
  • \( 92.3 \, \text{kJ} \)
  • \( 184.6 \, \text{kJ} \)
Show Solution

The Correct Option is A

Solution and Explanation

The enthalpy of formation (\( \Delta H_f^\circ \)) quantifies the heat exchanged during the synthesis of 1 mole of a compound from its constituent elements in their standard states. For hydrogen chloride (HCl), this value is stated as \( -92.3 \, \text{kJ/mol} \).When 2 moles of HCl are synthesized, the cumulative heat exchanged is calculated as:\[\text{Total heat} = 2 \times (-92.3) = -184.6 \, \text{kJ}\]Consequently, the total heat released amounts to \( -184.6 \, \text{kJ} \).
Was this answer helpful?
0

Top Questions on Thermodynamics