Barbara completed an assignment for extra credit in science class. She used a pH meter to find the pH of different substances.

Question

After she finished measuring the pHs, she created a diagram that showed the substances arranged in order from the most acidic to the most basic.

If Barbara added lemon juice—pH 2.2—to her investigation, where should it appear in her diagram?
A.
to the left of cola
B.
between milk and water
C.
between water and blood
D.
between soap and bleach

Answer 1

To determine where lemon juice (pH 2.2) should appear on Barbara's diagram, we need to consider the common pH values of the other substances mentioned:

• Cola typically has a pH around 2.5 to 3.5.
• Milk has a pH around 6.7 to 6.9.
• Water has a neutral pH of 7.
• Blood has a pH around 7.4.
• Soap generally has a pH range of 9 to 10.
• Bleach typically has a pH around 12.

Since lemon juice is very acidic with a pH of 2.2, it should be positioned to the left of cola, as it is more acidic than cola (which has a pH greater than 2.2).

Thus, the correct answer is: A. to the left of cola.