The ph is a measure of the concentration of the hydrogen ion (h+) in water. highly acidic water has a very high h+ concentration, while basic water has very low h+ concentrations. the ph scale is a logarithmic scale, such that a difference of one ph unit means a 10-fold difference in h+ concentration. the mathematical relationship between ph and h+ concentration ([h+]) is

ph = –log [h+] or [h+] = 10-ph where [h+] is in moles per liter.

use a scientific calculator to calculate [h+] for the following ph values:

7 (a neutral solution)

5.6 (unpolluted rainwater)

3.7 (first acid rain sample in north america)

how many times higher is the concentration of h+ in the hubbard brook sample than in unpolluted rainwater?