Assignment #Acidic, Basic, and Neutral Solutions

Biology

Mrs. McCarthy

Thursday, April 20, 2023

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-

Examples: baking soda, soap, egg whites, bleach

2. Neutral solutions Have an equal amount of hydrogen and

hydroxide ions

H2O

H+ OH-

Examples: pure, distilled water

I. Acidic, Basic, and Neutral Solutions

B. pH scalep = potentialH = hydrogen ionsStandard scale of hydrogen ions present

in a solutionThere 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

How many times more acidic is pH 5 than pH 8?

How many times more basic is pH 11 than pH 7?

1,000 times

10,000 times

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:

Abbreviation Number 1.0 x 10-5 .000012.5 x 10-3 .00251.0 x 102 1003.4 x 102 3401.0 x 105 100,000105 100,0006.0 x 106 6,000,000

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:

1. Write 123,000,000,000 in scientific notation.

2. Write 0.00000034 in scientific notation.