Bio Unit 2: Acids and Bases Quiz BWHS

Pure water has a pH of 7. Pure water _______.

• is a base

• is a neutral substance

• could be either an acid or a base

• is an acid

Answer explanation

Pure water has a pH of 7, indicating it is neither acidic nor basic. Therefore, pure water is classified as a neutral substance, making 'is a neutral substance' the correct answer.

Which is the stronger acid?

• pH 1

• pH 4

• pH 8

• pH 13

Answer explanation

The pH scale measures acidity; lower values indicate stronger acids. A pH of 1 is much more acidic than pH 4, pH 8, or pH 13, making pH 1 the strongest acid among the choices.

Which of the following is most likely to be basic:

• Lemon juice

• Vinegar

• Laundry detergent

• Coke

Answer explanation

Laundry detergent is most likely to be basic because it contains alkaline substances that help in cleaning. In contrast, lemon juice, vinegar, and Coke are acidic in nature.

When dissolved in water, acids produce:

• bases

• salts

• hydrogen ions

• hydroxide ions

Answer explanation

When acids dissolve in water, they release hydrogen ions (H+), which is what characterizes them as acids. Therefore, the correct answer is hydrogen ions.

The pH of a solution is tested, and it is found to be a basic solution. Of the following choices, what could the pH have been?

• 3

• 7

• 9

• 5

Answer explanation

A basic solution has a pH greater than 7. Among the choices, only 9 is greater than 7, indicating it is basic. The other options (3, 5, and 7) are either acidic or neutral.

pH is the measure of the concentration of ______.

• Acids

• H+ ion

• OH- ion

• Base

Answer explanation

pH measures the concentration of hydrogen ions (H+) in a solution. A lower pH indicates a higher concentration of H+ ions, making the solution more acidic. Therefore, the correct answer is H+ ion.

If a solution is basic which ion will be more present?

• H+

• K+

• OH-

• H-

Answer explanation

In a basic solution, the concentration of hydroxide ions (OH-) is higher than that of hydrogen ions (H+). Therefore, OH- is the ion that will be more present in a basic solution.

Stronger acids have a pH closer to...

• 7

• 14

• 0

• 9

Answer explanation

Stronger acids have a pH closer to 0, indicating a higher concentration of hydrogen ions. A pH of 7 is neutral, while 14 is basic, making 0 the correct choice for stronger acids.

Neutralization is the process of an acid and a base reacting to form what? Select all that apply

• An ionic salt

• Hydronium ions

• NaCl

• Water

Answer explanation

Neutralization of an acid and a base produces an ionic salt and water. Hydronium ions are consumed in the reaction, and NaCl is just one example of an ionic salt, not a general product of all neutralizations.

Which of the following is an acid?

• vinegar

• bleach

• sugar in water

• starch in water

• toothpaste in water

Answer explanation

Vinegar is an acid because it contains acetic acid, which gives it its sour taste and acidic properties. The other options, such as bleach, sugar, starch, and toothpaste, do not exhibit acidic characteristics.