Suppose you need to differentiate the solids in each pair using their solubility difference in water and ethanol (as shown in the table). So you dissolve 0.40 g of each solid into 10 mL each solvent (Each solution composes one solvent and one solute). The solids in which pair CANNOT be differentiated using their solubility difference in water and ethanol?

• Na ₂ CO ₃ and CH ₃ COONa (anhydrous)
• NaOH and NaOH ₃
• NaCI and NaOH
• NaOH and CH ₃ COONa (anhydrous)
• NaOH ₃ and CH ₃ COONa (anhydrous)

NaCl NaOH CH3COONa (anhydrous) NaCO3 NaNO3 Solubility in Water (20 C, 1 atm) g/100 mL 35.9 111 123 21.5 87.6 Solubility in Ethanol (20 C, 1 atm) g/100 mL 0.051 (25C) 13.9 5.3 Insoluble Slightly soluble