Question

A student uses an indicator to measure the pH of a solution. The indicator shows a pH of 7. What must be true of this solution?

The solution contains neither hydronium ions nor hydroxide ions.

The solution has equal amounts of hydronium ions and hydroxide ions.

The solution is acidic.

The solution is basic.

Answer 1

The solution has equal amounts of hydronium ions and hydroxide ions.

Step-by-step explanation:

From the very beginning it is clear that answer choices 3 and 4 are incorrect, as a pH of 7 means it is neutral.

The pH of anything being 7 (neutral) means it is neither an acid (1-6) nor a base (8-14).

This essentially levels things out meaning that there will be an equal amount.

Answer 2

A pH of 7 is known as "natural"

A pH below 7 is an acid

A pH above 7 is a base

Acids give up hydrogen ions, shown as H+
Bases accept H+, hydrogen ions.

Equilibrium is when a chemical reaction doesn't favor the reactants or products and can go in reverse.
pH of 7 are related to Equilibrium.

With the info I have given you, it's obviously not one of the last 2 you listed.

pH measures the alkalinity and acidity of a solution by the Hydrogen ions, H+. Therefore, the solution has to have Hydrogen ions to react/be measured by the pH paper.

Therefore, your answer is the 2nd statement.
The solution has equal amounts of hydronium ions and hydroxide ions.