Which of the following does NOT describe an acid?

A.
It has a sour taste.

B.
It has a pH above 7.

C.
It turns litmus paper red.

D.
It will burn skin.

B.

It has a pH above 7.

B. It has a pH above 7.

To figure out which of the given options does not describe an acid, we need to understand the properties and characteristics of acids.

Option A states that an acid has a sour taste. This is true for many acids, such as vinegar and citric acid.

Option B claims that an acid has a pH above 7. This is incorrect. Acids have a pH below 7, with lower pH values indicating stronger acidity.

Option C mentions that an acid turns litmus paper red. This is generally true, as most acids turn blue litmus paper red. However, it is essential to note that this test alone cannot be used as a definitive identification of an acid.

Option D states that an acid will burn skin. This is also accurate for strong acids, such as sulfuric acid. Strong acids can cause severe burns.

By eliminating the options that describe acids correctly, we conclude that option B, which states that an acid has a pH above 7, does NOT describe an acid.