Question

Which of the following causes a precipitate to form?

Answer 1

Answer: Option (A) is the correct answer.

Explanation:

When in a chemical reaction, a liquid solution results in the formation of an insoluble solid then this solid is known as a precipitate.

For example, $Pb(NO_{3})_{2}(aq) + 2NaI(aq) \rightarrow PbI_{2}(s) + 2NaNO_{3}(aq)$

Here $PbI_{2}$ solid formed is a precipitate as it remains insoluble in the reacting solution.

Hence, we can conclude that out of the given options atoms combining in a solution to form a solid causes a precipitate to form.

Answer 2

The correct answer is A. Atoms combining in a solution to form a solid

What this means is that atoms bond together to form a physical presence to appear and becomes deposited in a solution in solid form.