To calculate the standard enthalpy change for the dissolution of sodium chloride in water, we need to know the heat of solution for NaCl. The heat of solution Hsol for NaCl is approximately -3.88 kJ/mol.First, we need to determine the number of moles of NaCl in 5.00 g:moles = mass / molar massmoles = 5.00 g / 58.44 g/molmoles = 0.0856 molNow, we can calculate the enthalpy change for the dissolution of 5.00 g of NaCl:H = moles HsolH = 0.0856 mol -3.88 kJ/molH = -0.332 kJThe standard enthalpy change for the dissolution of 5.00 g of sodium chloride in 100 mL of water at 25C is approximately -0.332 kJ.