OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दी2.0 moles of liquid water at \( 100^\circ\text{C} \) is completely converted to ice at \( 0^\circ\text{C} \) at 1 bar pressure. Given that the heat capacity of liquid water is \( 4.2\text{ J g}^{-1\,\circ}\text{C}^{-1} \) and the enthalpy of fusion of ice is \( 6.00\text{ kJ mol}^{-1} \), the total enthalpy change (\( \Delta H \)) for this process is:
Correct answer · Option 3
-27.12 kJ
Explanation
Per mole: \( \Delta H_1 = -(18 \times 4.2 \times 100) = -7.56\text{ kJ mol}^{-1} \) and \( \Delta H_2 = -6.00\text{ kJ mol}^{-1} \). Total per mole = \( -13.56\text{ kJ mol}^{-1} \). For 2.0 moles: \( \Delta H = 2 \times (-13.56) = -27.12\text{ kJ} \).
