John hypothesized that dissolving salt into water produced a chemical reaction because the salt completely disappeared in the water. He dissolved 10 grams of salt into 500 mL of pure water. After leaving the beaker in the sunlight a few days, the water completely disappeared and salt crystals were left in the bottom of the beaker. Based on this observation, John knew his hypothesis was incorrect because-

Explanation:

John knew his hypothesis was incorrect because he was left with the exact some compounds as he had started with. Something is only a chemical reaction if it changes the actual chemical structure and/or identity of a reactant. In this case, John mistook a physical change for a chemical change. The salt changes forms from solid to aqueous (dissolved in water), but did not change on a molecular level. Also, no new products were produced in the reaction and it did not show any of the 5 indicators of chemical reactions (temperature, colour and/or odour changes, formation of precipitate, production of a gas)

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