Question

An ulcer patient has been told to avoid acidic foods. If he drinks coffee, with a pH of 5.0, it bothers him, but he can tolerate both tap water, with a pH of 5.8, and milk, with a pH of 6.9 .In order to make 10 oz of a milk-coffee drink with a pH of 5.8, how many ounces of each are required?

Answer 1

The equation should look like :
[H+] = (1-a)(x) + (a)(y)
Where:
5.8 = -log [H+]
5.0 = -log x 
6.9 = -log y 
(1-a) = proportion of x
a = proportion of y
so calculating a will give you the result of how many ounces are required