Preparing an Insoluble Salt Flashcards

All 5 cards in this deck

What are the steps to predict whether a precipitate forms when two solutions are mixed?
e.g. silver nitrate solution + sodium chloride solution

1. Swap the positive ions to give the two possible products: silver chloride and sodium nitrate.
2. Apply the solubility rules: silver chloride is insoluble, sodium nitrate is soluble.
3. Name the insoluble product as the precipitate: silver chloride.

What are the steps to prepare a pure, dry sample of an insoluble salt?
e.g. barium sulfate from barium chloride and sodium sulfate solutions

1. Mix the two solutions so the precipitate of barium sulfate forms.
2. Filter to collect the precipitate.
3. Wash it with distilled water and leave it to dry (e.g. in a warm oven).

Why is the precipitate washed with distilled water on the filter paper?

To remove the soluble salt solution and other soluble impurities.

True or false? Mixing any two solutions of soluble salts produces a precipitate.

False. A precipitate forms only if one of the possible products is insoluble.

Which two solutions could be mixed to make insoluble lead chloride?

Lead nitrate solution and a soluble chloride such as sodium chloride solution.