# What is a substance with a pH of 4 called?

Nov 21, 2017

Acidic

#### Explanation:

pH is just a fancy scale for representing the concentration of ${H}_{3} {O}^{+}$ (hydronium) ions in the solution. To find the concentration of hydronium ions, you just take ${10}^{- p H}$, which simplifies to $\frac{1}{10} ^ \left(p H\right)$, if you prefer seeing it that way.

As you can see, therefore, substances with smaller pH values will have a $\textcolor{red}{\text{larger hydronium ion concentration.}}$ and we call these $\textcolor{red}{\text{acidic}}$

Similarly, substances with larger pH values will have $\textcolor{b l u e}{\text{lower hydronium ion concentrations}}$, and we call these $\textcolor{b l u e}{\text{basic}}$

Our baseline is that a $\textcolor{g r e e n}{\text{pH of 7 is considered neutral}}$. Anything above is basic, anything lower is acidic.

So, bearing all that in mind, a pH of 4 would be considered $\textcolor{red}{\text{acidic}}$

Hope that helps :)