Question

The pH of sea water is 7.6 and the PH of milk of magnesium is 10.5. 1.What are the hydrogen ion concentrations of each? 2.How many times great is the hydrogen ion concentration of the sea water than of milk of magnesium?

Answer 1

2.5*10^-8 for sea water, 3.16*10^-11 for milk of magnesium, and 790 times greater

Explanation:

We're trying to find the concentration of H+ in the solution using the pH, so

let's define pH first.
pH=-log(H+)

This equation can be re-written as
H+ = 10^(-pH), or H+ = 1/(10^pH)

The pH of sea water is 7.6, so the concentration of H+ in sea water is 10^(-7.6), which is about 2.5*10^-8

The pH of milk of magnesium is 10.5, so the concentration of H+ in milk of magnesium is 10^(-10.5), which is about 3.16*10^-11

To compare how much more the concentration of the hydrogen ion is, we just divide

(2.5*10^-8)/(3.16*10^-11) = 791, or 790 with sig figs.