The pH of a sample of lake water was originally 6 when measured in 1987. When measured again in 2014, the pH of the water was 4.
How has the concentration of hydrogen ions in the lake changed?
In 1987 the ph of water is 6 means less acidic it means that the concentration of H ion in water is less
in 2014 the ph of water is 4 means the H ion increased that's why the water is acidic