Answer:
pH= 9.9 This pH is alkaline
Step-by-step explanation:
pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH can be measured in an aqueous solution using a numerical value scale that measures the acidic solutions (highest concentration of hydrogen ions) and the alkaline solutions (base, lowest concentration) of the substances.
The numerical scale that measures the pH of substances ranges from 0 to 14. The most acidic substances approach number 0, and the most alkaline (or basic) substances that approach number 14. And a pH value of 7 is neutral; This means that the substance or solution is neither acidic nor alkaline.
The pH is expressed as the negative logarithm (base 10) of the concentration of hydronium ions [H₃O⁺] or hydrogen ions [H⁺]. This is:
pH= -log₁₀ [H₃O+]= -log₁₀ [H⁺]
also expressed as
pH= -log [H₃O+]= -log [H⁺]
So, in this case, you know that [H⁺]=1.25*10⁻¹⁰ M
Replacing in the definition of pH:
pH= -log 1.25*10⁻¹⁰
You get:
pH= 9.9
pH is alkaline