Think Pair Share What can you tell me

Think, Pair, Share – What can you tell me about acids and bases? – Can you think of some acids and bases that you might find at home? – Are all acids harmful? – What foods that we eat or drink are bases? Can you tell the difference by taste?

p. H Basics • The p. H scale is a measure of hydrogen ion concentrations. On the p. H scale, high concentrations of hydrogen ions are denoted by low p. H and low concentrations of hydrogen ions are denoted by high p. H.

p. H – “Potential for Hydrogen” • Red cabbage extract changes to many colors depending on acidity. Acidity is measured on a p. H scale. p. H stands for "potential for Hydrogen. " • Acidity is caused by hydrogen atoms that have lost their electrons and are roaming free in water [H+]. The scale goes from 0 to 14.

More Info on Atoms, Molecules , & Ions • http: //www. miamisci. org/ph/hoh. html • Please go to the website above for more information on atoms, molecules, and ions.

Table 17 -2, p. 518

p. H Scale The opposite of acidic is alkaline (or basic). Alkaline gets its name from the "al kali" plant whose ashes are capable of neutralizing acids.

Cabbage Juice • There are substances which have the property of changing their color when they come in contact with an acidic or basic environment. These substances are called p. H indicators. • Red cabbage juice is a natural p. H indicator.

Cabbage Juice • Cabbage juice turns bright pink in the presence of an acid. • Cabbage juice turns blue/green/yellow in the presence of a base.

Grape Juice • Grape juice turns deep red in the presence of an acid. • Grape juice turns blue in the presence of a base. • Grape juice is a natural p. H indicator.

Acids vs. Bases Acids • Taste sour • Examples include lemons, vinegar, cola, and green apples. Bases • Taste bitter • Examples include cleaning solutions like soapy water, detergents, baking soda, and shampoo.

Extra Info for the Test • Distilled water is a neutral. • High amounts of hydrogen ions mean a low p. H value. This is an acid. • Low amounts of hydrogen ions mean a high p. H value. This is a base. • Examples of Acids – lemon juice, orange juice, vinegar, colas, and green apples • Examples of Bases – soaps, detergents, baking soda, shampoo, borax, limewater, and ammonia.