Answer: 5
Explanation: pH is defined as potential of hydrogen electrode and measures the acidity or alkalinity of a substance.
It is calculated by taking negative logarithm of [tex]H^+[/tex] ion concentration.
[tex]pH=-log[H^+]=-log[0.00001]=-log[10^{-5}]=-(-5)log[10]=5[/tex]
Thus the given solution has pH of 5 which means this is an acidic solution.