2 What is an Acid?Acid – a substance that produces H+ (hydrogen ions) in solution. It is the ability to produce the H+ ions that gives acids their characteristic properties.
3 Properties of AcidsAcids taste sour. (never use taste to test for the presence of an acid. They can cause tissue damage.)Acids are electrolytes and can conduct electricity
4 Properties of AcidsAcids are corrosive – they react strongly with metals and “eat away“ at the metals producing hydrogen gas. Contact with skin may result in severe burns and tissue damageAcids react with indicators, organic compounds that changes color in a n acid or a base.
5 Acids Affect Indicators, by changing their color Blue litmus paper turns red in contact with an acid (and red paper stays red).
6 Some Common Acids Name Formula Where Found Acetic acid CH3COOH vinegar Acetylsalicylic acidHOOC-C6H4-OOCCH3aspirinAscorbic acidH2C6O6citrus fruitsBoric acidH3BO3eyewash solutionsHydrochloric acidHClgastric juice in stomachCarbonic acidH2CO3carbonated drinksSulfuric acidH2SO4car batteries, fertilizers
7 How are acids used?sulfuric acid – car batteries, fertilizer, dehydrating agent (removes H2O from materials).Phosphoric Acid – fertilizers, used in soft drinks. Harmful to environment when added to detergents.Nitric acid – fertilizers, explosives.Hydrochloric acid – used to clean surfaces in industry. also known as muriatic acid.
8 What is a Base?base – substance that produces hydroxide ions, OH-, in a solution.
9 Properties of Bases Most bases are crystalline solids. In solution, bases feel slippery, like soap.Bases taste bitter.Bases are corrosive – contact with skin may result in severe burns and tissue damageNEVER USE TASTE TO TEST FOR THE PRESENCE OF A BASE. THEY CAN CAUSE TISSUE DAMAGE
10 Properties of Bases Bases are electrolytes and conduct electricity. Bases react with indicators to produce a predictable color change.
11 Common Bases and Their Uses NameFormulaUsesAluminum hydroxideAl(OH)3deodorant, antacidCalcium hydroxideCa(OH)2Leather production, manufacture of mortar and plasterMagnesium hydroxideMg(OH)2laxative, antacidsodium hydroxideNaOHdrain cleaner, soap makingAmmoniaNH3household cleaner, fertilizer,production of rayon and nylon
12 Strength of Acids and Bases Strong acids – ionizes almost completely in solution (very soluble)Weak acids – acid that only partly ionizes in solution (slightly soluble)Strong base – dissociates completely in solution (very soluble)Weak base – base that only partly dissociates in solution (slightly soluble)
13 Strength and Concentration Concentration – the amount of acid or base dissolved in solution (g/100 mL)Strength – refers to the ease that the acid or base forms ions in solution. The more ions that are produced the stronger the acid or base
14 What is pH?pH is the measurement of H3O+ (hydronium ions) in solution.pH is a scale used to measure how acidic or basic a solution is.Below 7 is acidicAbove 7 is basic7 is neutral
15 Acids have a pH less than 7 Baseshave a pH greater than 7
16 Acids have a pH less than 7 Baseshave a pH greater than 7