At 25°C, the Standard Enthalpy of Formation of Anhydrous Sodium $\Delta$

question 105

Multiple Choice

At 25°C, the standard enthalpy of formation of anhydrous sodium carbonate is -1130.9 kJ/mol, whereas the standard enthalpy of formation of sodium carbonate monohydrate is -1430.1 kJ/mol. Determine $\Delta$ H° at 25°C for the reaction Na₂CO₃(s) + H₂O(l) $\rarr$ Na₂CO₃·H₂O(s) .
(Given: $\Delta$ H°_f[H₂O(l) ] = -285.8 kJ/mol)

• A)-13.4 kJ/mol
• B)-285.8 kJ/mol
• C)-585.0 kJ/mol
• D)-299.2 kJ/mol
• E)-156.3 kJ/mol

---

Definitions:

Taxonomy

Naming and classifying species in a systematic way.

Differentiation

The process by which unspecialized cells become specialized into one of the many cell types that make up an organism.

Scientific Method

A systematic approach to research and knowledge acquisition, involving observation, hypothesis, experimentation, analysis, and conclusion.