Question

if a sample of a certain solution is determined to have a [H30+] concentration of 1.48 X 10-2moles/liter, what is its pH? Round off your answer to one decimal place.

Answer 1

The pH of a solution is the negative logarithm of the hydrogen or hydroxonium ion concentration to the base of 10. That is

`pH=-log_(10)[H_3O^+]`

From the question, we have that

`[H_3O^+]=1.48*10^(-2)`

So the pH becomes

`\begin{gathered} pH=-log_(10)(1.48*10^(-2)) \\ =-(log_(10)1.48+log_(10)10^(-2)) \\ =-(0.170261+(-2) \\ =-(0.170261-2) \\ =-(-1.8297) \\ =1.8297 \end{gathered}`

Hence the answer is 1.8 to one decimal place