Chapter 4.5, Problem 9E

Reminder Round all answers to two decimal places unless otherwise indicated.

The pH Scale Acidity of a solution is determined by the concentration $H$ of hydrogen ions in the solution (measured in moles per liter of solution). Chemists use the negative of the logarithm of the concentration of hydrogen ions to define the $\text{pH}$ scale:

$\text{pH}=-\log H$

Lower $\text{pH}$ values indicate a more acidic solution.

a. Normal rain has a $\text{pH}$ value of $5.6$. Rain in the eastern United States often has a $\text{pH}$ level of $3.8$. How much more acidic is this than normal rain?

b. If the $\text{pH}$ of water in lake falls below a value of $5$, fish often fail to reproduce. How much more acidic is this than normal water with a $\text{pH}$ of $5.6$?