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Assignment # Acidic, Basic, and Neutral Solutions. Biology Mrs. McCarthy Thursday, November 6, 2014. I . Acidic, Basic, and Neutral Solutions. A. Solutions are acidic, basic, or neutral depending on the concentration of hydrogen ions (H+) in the solution. 1. Acidic solutions
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Assignment #Acidic, Basic, and Neutral Solutions Biology Mrs. McCarthy Thursday, November 6, 2014
I.Acidic, Basic, and Neutral Solutions A. Solutions are acidic, basic, or neutral depending on the concentration of hydrogen ions (H+) in the solution.
1. Acidic solutions • contain more hydrogen ions (H+) • Release hydrogen as they dissolve HCl H+ Cl-
Examples: grapefruit juice, vinegar, coffee, digestive juices
2. Basic solutions • contain more hydroxide ions (OH-) • Release hydroxide ions as they dissolve NaOH Na+ OH-
2. Neutral solutions • Have an equal amount of hydrogen and hydroxide ions H2O H+ OH-
I.Acidic, Basic, and Neutral Solutions B. pH scale • p = potential • H = hydrogen ions • Standard scale of hydrogen ions present in a solution • There is a 10x difference between each number in the pH scale
ExamplepH 2 is 10x stronger than pH 3 pH 3 is 10x stronger than pH 4 Therefore: pH 2 is 100x stronger than pH 4
1,000 times How many times more acidic is pH 5 than pH 8? How many times more basic is pH 11 than pH 7? 10,000 times
Abbreviation Number 1.0 x 10-5 .00001 2.5 x 10-3 .0025 1.0 x 102 100 3.4 x 102 340 1.0 x 105 100,000 105 100,000 6.0 x 106 6,000,000 Scientific notation can be used to show the difference between numbers on the pH scale. Scientific notation is a way to make these numbers easier to work with. In scientific notation, you move the decimal place until you have a number between 1 and 10. Then you add a power of ten that tells how many places you moved the decimal. Here are some examples of scientific notation and the numbers it represents:
Use scientific notation to show how many times more acidic pH 2 is than pH 12: 2 is 10 places away from 12 on the scale 10 10 = 10000000000 OR 1 x 10 10 times more acidic
Practice: • Write 123,000,000,000 in scientific notation. • Write 0.00000034 in scientific notation.