A gr. 10 chemistry question: word problem .please help?

Question

A newspaper article claims that acid rain falling in your area has a pH of 4.0, "almost the same as vinegar, which has a pH of 3.0." Explain why this article is misleading.

Answer 1

The pH scale works on a power of ten basis. Therefore a a pH of 4 is ten times greater than a pH of 3.  

Answer 2

The pH scale is a logarithmic scale with base 10.  It's similar in concept to the scale that rates earthquakes.  For example. an earthquake with a richter scale reading of 2.0 is 100 times stronger than an earthquake of magnitude 1.0.  The same is true of pH and acid/base strengths.  A one point difference is equivalent to a 100% difference.