Logarithm Word Problems Worksheets
How to Tackle Logarithms in Word Problems Logarithmic word problems, in my experience, generally involve evaluating a given logarithmic equation at a given point and solving for a given variable; they're pretty straightforward. On the other hand, exponential word problems tend to be much more involved, requiring, among other things, that the student first generate the exponential equation, and perhaps then also find the value of one of the variables before beginning to answer the actual question. Since log problems are typically simpler, I'll start with them. Chemists define the acidity or alkalinity of a substance according to the formula. "pH = -log [H+]" where [H+] is the hydrogen ion concentration, measured in moles per litre. Solutions with a pH value of less than 7 are acidic; solutions with a pH value of greater than 7 are basic; solutions with a pH of 7 (such as pure water) are neutral. Suppose that you test apple juice and find that the hydrogen ion concentration is [H+] = 0.0003. Find the pH value and determine whether the juice is basic or acidic. You test some ammonia and determine the hydrogen ion concentration to be [H+] = 1.3 × 10-9. Find the pH value and determine whether the ammonia is basic or acidic. In each case, I need to evaluate the pH function at the given value of [H+]. a) In the case of the apple juice, the hydrogen ion concentration is [H+] = 0.0003, so: pH = -log[H+] = –log [0.0003] = 3.52287874528... ...which is less than 7, so this is acidic.
What's Up With Word Problems?
To solve algebra word problems translate the problem into mathematical language using only the essential facts. A variable in an equation is just an unknown quantity; you can call it anything. Classify the problem into a familiar grouping of problems.