7-5.6 Distinguish between acids and bases and use indicators to determine their pH.

Acids Can be idenitified by their sour taste Examples: lemons ,oranges, grapefruits, and limes Reacts with metals Turns blue litmus red

Bases Can be identified by their bitter taste and slippery feel Examples: Milk of Magnesia, ammonia Bases turn red litmus blue

Turns blue litmus red Turns red litmus blue Test for Acids or Bases

Litmus paper Blue litmus paper turns red in an acid. Blue litmus paper stays blue in a base Red litmus paper turns blue in a base. Red litmus paper stays red in an acid. RED ACID BLUE BASE Purple in a solution that is neutral

Properties of Acidic Solutions Sour taste Conduct electricity- some batteries contain acids Corrosives (break down certain substances) corrode fabric,skin, and paper Some react strongly with metals- leaving holes in the metal

Properties of Bases Most soaps are bases- feel slippery Bases are corrosives like acids They can cause burns and damage body tissue Bases can conduct electricity like acids They are not as corrosive to metals as acids.

Acids Vinegar- used in salad dressings Citrus fruits ( contain Vitamin C) Ants that sting inject acids Hydrochloric acid- used to remove impurities from the surface of metals- Clean mortar from brick walls Used to make fertilizers, dyes, and plastic

Bases Used in plastics, soaps, ammonia, and other cleaning products Lime- used to mark lines on athletic fields and can make soil less acidic

What is pH? pH is a way to measure how acidic and basic a solution is. pH scale ranges from 0-14 with pH 7 being neutral Each pH unit is a change in acidity that is multiple of 10. An acid with a pH scale of 2 is 10 times stronger than a acid with a pH of 3 and 100 times stronger than an acid with a pH of 4.