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Chemistry · THERMODYNAMICS

हिन्दी

When a balanced thermochemical equation is multiplied by a factor of 2, the numerical value of its standard enthalpy of reaction (\( \Delta_r H^\ominus \)):

  1. Remains unchanged
  2. Becomes half
  3. Is squared
  4. Is doubled

Correct answer · Option 4

Is doubled

Explanation

Enthalpy is an extensive property; multiplying the stoichiometric coefficients by 2 also multiplies the enthalpy of reaction by 2.

Related questions

At 298 K, 18 g of liquid water evaporates into steam. Given \( \Delta_{\text{vap}}H^\ominus = 44.01\text{ kJ mol}^{-1} \) and \( R = 8.314\text{ J K}^{-1}\text{mol}^{-1} \), the internal energy of vaporisation (\( \Delta_{\text{vap}}U^\ominus \)) is approximately:→Which of the following substances has a standard molar enthalpy of formation (\( \Delta_f H^\ominus \)) equal to zero at 298 K and 1 bar by convention?→For the reaction \( 4\text{Fe}(s) + 3\text{O}_2(g) \rightarrow 2\text{Fe}_2\text{O}_3(s) \) at \( 298\text{ K} \), \( \Delta_r H^\circ = -1648\text{ kJ mol}^{-1} \) and \( \Delta_r S^\circ = -549.4\text{ J K}^{-1}\text{mol}^{-1} \). What is the total entropy change \( \Delta S_{\text{total}} \)?→2.0 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:→
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