Which is a correct step in a scientific experiment involving acids and bases? (3 points)Mixing two acids to form a neutral solution.Using an indicator to measure the hydrogen ion concentration of a solution.Pouring acid onto an indicator to measure the pH of the indicator.Dissolving an indicator in an acidic solution to increase its pH.

The correct step in a scientific experiment involving acids and bases is: Using an indicator to measure the hydrogen ion concentration of a solution.

Here's why:

1. Mixing two acids will not form a neutral solution. Acids, by definition, have a pH less than 7. Mixing two acids will result in a solution that is still acidic.

2. Using an indicator to measure the hydrogen ion concentration of a solution is a correct step. Indicators are substances that change color depending on the pH of the solution they are in. They are often used in labs to determine whether a solution is acidic or basic.

3. Pouring acid onto an indicator to measure the pH of the indicator is not a correct step. The purpose of an indicator is to measure the pH of the solution it is in, not the other way around.

4. Dissolving an indicator in an acidic solution to increase its pH is not a correct step. Adding an indicator to a solution does not change the pH of the solution. The indicator simply changes color to reflect the pH of the solution.