Question

question 9 which of the following is a characteristic of acids? a they taste sweet. b they produce oh - ions in water. c they feel slippery. d they turn litmus paper red.

Explanation:

Acids have a sour taste (not sweet), they turn blue litmus paper red (not just any litmus paper red as in option D which is ambiguous), bases feel slippery (so option C is a base property), and bases produce \(OH^-\) ions in water (so option B is a base property). Acids are characterized by their ability to turn blue litmus paper red (a more accurate description related to acid - litmus interaction) and having a sour taste. Among the given options, the most characteristic property of acids (in the context of common acid - base property knowledge) is that they turn litmus paper red (assuming it's blue litmus paper as a standard test for acids).

Answer:

A. They taste sweet. (Incorrect as acids are sour)
B. They produce \(OH^-\) ions in water. (Base property)
C. They feel slippery. (Base property)
D. They turn litmus paper red. (Assuming blue litmus paper, which is a characteristic of acids)

So the answer is D.