pH of lemon juice

Statement

A lemon juice has $[\text{H}^+] = 10^{-2{,}5}$ mol/L. Calculate the pH and state whether it is acidic, neutral or basic.

Solution

By definition $\text{pH} = -\log_{10}[\text{H}^+]$: $\text{pH} = -\log_{10}(10^{-2{,}5}) = 2{,}5.$ Since $\text{pH} = 2{,}5 < 7$, the solution is $\boxed{\text{acidic}}$ (as expected for a lemon juice).

Links

Topics: Logarithmic function
Concepts: Logarithm · Ph · Logarithmic scale
Functions: Logarithmic function
Skills: Calculating · Interpreting a graph
Exercise type: Modelling problem