Which of the following is an acid?

NaOH
NaCl
HCI
CH4

HCl

Explanation:

Some easy ways to identify if a compound is an acid is to locate an H+ proton, while basic compounds will have an OH- ion.

Examine all the choices:

A) NaOH

Already, we see that OH is here, so it's a base, not an acid. Eliminate.

B) NaCl

This doesn't have an H+ or an OH-, so it's not an acid. It's actually a salt. Eliminate.

C) HCl

This does have an H+, so it's an acid.

D)

Although this does have an H, it's a hydrocarbon - an organic compound. So, it's not an acid.

The answer is thus C.

~ an aesthetics lover

the most logical answer would be a

i think that d. wind is the answer.   i missed the question when i answered a. currents.