Вопрос № 1. Properties of amphoteric hydroxides, acids and salts.

A solution of calcium hydroxide was placed in two test tubes. A solution of a strong electrolyte 1 was added to the first tube which led to the formation of a precipitate. A solution of a weak electrolyte 2 was added to the second tube which also led to the formation of a precipitate. Of the following substances, decide which substances are 1 and 2.