#29 ACIDS, BASES, and pH

Acids, Bases, and pH Vocabulary Solution Acid Base pH scale Ion- an atom or molecule with a positive (+) or negative (-) charge 2/22/2019 Template copyright 2005 www.brainybetty.com

Template copyright 2005 www.brainybetty.com Solutions A solution is also called a homogenous mixture, which is a mixture of two or more substances that is identical throughout. Many solutions have certain properties that make them an acid or a base 2/22/2019 Template copyright 2005 www.brainybetty.com

Acids Acids are found in a your medicine cabinet, refrigerator, and on your kitchen shelves Examples of acids include: aspirin, vitamin C, eyewash, oranges, grapes, lemons, grapefruit , apples, milk, tea, pickles, vinegar and carbonated drinks

Why are acids important? Food digestion! You could not digest food if it were not for gastric acid in your stomach. The manufacture of dyes, synthetic fibers, fertilizers, and explosives involves the use of acids.

Template copyright 2005 www.brainybetty.com Acids Acids taste sour when dissolved in water Produce a burning or prickly feeling on the skin Acids react with carbonates (like baking soda) and most metals Acids have a pH of less than 7 Produce hydrogen ions (H+) when dissolved in water Examples of acids can be found in many foods such as; oranges, tomatoes, vinegar, and lemons. 2/22/2019 Template copyright 2005 www.brainybetty.com

Bases Bases are also found in household products. Examples of bases include: milk of magnesia, deodorants, ammonia and soap.

Template copyright 2005 www.brainybetty.com Bases Bases taste bitter Feel slippery or soapy Bases react with fatty acids and oils to dissolve them Bases have a pH of greater than 7 Produce hydroxide ions (OH-) when dissolved in water Examples of bases: soap, ammonia, antacids (Tums or Rolaids), tooth paste, baking soda, floor cleaner 2/22/2019 Template copyright 2005 www.brainybetty.com

Template copyright 2005 www.brainybetty.com pH scale The pH scale measures how acidic or basic a solution is, on a scale of 0-14 and is a measurement of acidity. pH stands for “potential of hydrogen”, which refers to the ions acids and bases release when dissolved in water. The ions create a chemical reaction when in contact with a pH indicator like red cabbage juice or pH paper, which turns the indicator a different color. Acids have a pH below 7. The lower the pH, the stronger the acid as that substance will release more hydrogen ions when dissolved. Bases have a pH above 7. The higher the pH, the stronger the base, as that substance will also release more hydroxide ions when dissolved. 2/22/2019 Template copyright 2005 www.brainybetty.com

Neutrals A substance is considered neutral if it has a pH of 7. Neutrals are neither an acid or a base. Example: Distilled (pure) water. When acids and bases combine, they chemically react and destroy each other’s chemical properties. This is called neutralization.

Red Cabbage Juice pH Scale

Bromthymol Blue pH Scale