Given pH = 6.75,

Is this acidic, basic or neutral?

How do you know?

Acidic.

Explanation:

pH is a logarithmic function of [H+]:

pH = - log[H+]

pH is usually (but not always) between 0 and 14. Knowing the dependence of pH on [H+], we can summarize as follows:

If pH < 7, then the solution is acidic.

If pH = 7, then the solution is neutral.

If pH > 7, then the solution is basic.

Given pH is 6.75 so it is acidic.