Acids Bases and Solutions Describing Acids and Bases

Acids, Bases, and Solutions

Describing Acids and Bases Details Main Ideas Properties An acid Of Acids • tastes sour • reacts with metals • turns litmus red “Corrosive” – An acid acting on a metal to Eat it away

Corrosion of steel tank car by sulfuric acid

Affects of Acid Rain Statue 1906 before significant acid rain

Affects of Acid Rain Same Statue 1986

Chapter 19. 2 Describing Acids and Bases Details Main Ideas Properties A Base Of Bases • tastes bitter • feels slippery • turns litmus blue An “indicator” is a substance that turns different colors in acids and bases

Properties of Acids Bases in Solutions Details Main Ideas Atoms in Acids & Bases An Acid forms H+ ions in solution with water HCl (in H 20) -> H+ + CLA Base forms OH- ions (hydroxide) in solution with water Na. OH (in H 20) -> Na+ + OH -

Properties of Acids Bases in Solutions Main Ideas p. H Scale Details The p. H scale measures the acidity of a solution • p. H < 7 is acidic • p. H > 7 is basic • p. H = 7 is neutral (pure water) If an acid reacts with a base it will form water and a salt

[H+] p. H 1 0 0 1 x 10 -1 1 1 x 10 -2 2 HCl Stomach acid Lemon juice 1 x 10 -3 3 1 x 10 -4 4 1 x 10 -5 5 Vinegar Soda Rainwater X Acids Example 10 1 x 10 -6 Neutral 1 x 10 -7 1 x 10 -8 1 x 10 -9 1 x 10 -10 Bases 1 x 10 -11 1 x 10 -12 1 x 10 -13 6 7 8 9 10 11 12 13 Milk Pure water Egg whites Baking soda Tums® antacid Ammonia Mineral lime - Ca(OH)2 Drano®

Digestion and p. H

Digestion & p. H Main Ideas Digestion Details Digestion breaks down complex food Molecules for use by the body These products are used for • Energy (cellular respiration) • Raw material for the body Mechanical & chemical digestion Mechanical Digestion – rips, crushes, grinds and mashes food particles Chemical Digestion – breaks large molecules down to simpler products

Digestion & p. H Main Ideas Enzymes aid chemical digestion Details Chemical digestion takes place with the help of “enzymes” Enzymes are “catalysts” – molecules that speed reactions Different enzymes need different p. H to operate effectively • Amylase in the saliva breaks down carbohydrate (sugars) @ p. H 7 • The stomach’s p. H is around 2. 0 for digestion of protein using the enzyme “pepsin

Digestion & p. H Main Ideas Chemical digestion & absorption Details Proteins are broken down to “amino acids” In the small intestine fluids contain the base HCO 3 - which creates a basic p. H of 8 Digestion is completed in the small intestine and absorption of the products into the blood stream begins

Acids, Bases and p. H Main Ideas Details Summary Write a short one paragraph summary of the material in these notes.