Concept explainers
The pH scale is used to measure the acidity or alkalinity of a solution. The scale ranges from 0 to 14. A neutral solution, such as pure water, has a pH of 7. An acid solution has a pH less than 7 and an alkaline solution has a pH greater than 7. The lower the pH below 7, the more acidic is the solution. Each whole-number decrease in pH represents a tenfold increase in acidity.
The pH of a solution is given by
where x represents the concentration of the hydrogen ions in the solution, in moles per liter. Use the formula to solve Exercises 119-120, Express answers as powers of 10.
a. Normal, unpolluted rain has a pH of about 5.6. What is the hydrogen ion concentration?
b. An environmental concern involves the destructive effects of acid rain. The most acidic rainfall ever had a pH of 2.4. What was the hydrogen ion concentration?
c. How many times greater is the hydrogen ion concentration of the acidic rainfall in part (b) than the normal rainfall in part (a)?
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Algebra and Trigonometry (6th Edition)
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