ACIDS & BASES

Properties of an Acid  Sour Taste  Corrosive  Changes color when reacting with an indicator  An indicator is an organic compound that changes color in acid and base.  Acids will turn blue litmus paper red

Common Acids  Foods such as citrus fruits, yogurt, pickles contain acid  Your stomach uses hydrochloric acid to digest food  Sulfuric, phosphoric, nitric, and hydrochloric acids are used in industrial applications

Common Acids AcidUses Acetic acidVinegar Acetylsalicylic acidAsprin Asorbic acidVitamin C Carbonic acidIn carbonated drinks Hydrochloric acidIn stomach, used to clean steel Nitric AcidUsed to make fertilizers Phosphoric acidUsed to make detergent, fertilizer, soft drinks Sulfuric acidCar batteries, fertilizers, and other chemicals

Properties of Bases  Bitter taste  Slippery to touch  Corrosive  Create a predictable color change with an indicator  Turns litmus paper blue  In their pure state, many bases are solids

Common Bases  Used in drain cleaners  Soap  Milk of magnesia

Common Bases BaseUse Aluminum hydroxideColor-fast farics, antacid, water treatment Calcium hydroxideLeather making, plaster Magnesium hydroxideLaxative, antacid Sodium hydroxideMakes soap, oven cleaner, drain cleaner, paper Sodium HypochloriteBleach AmmoniaCleaner, fertilizer, to make rayon and nylon

Solutions of Acids and Bases  Many common acids and bases are actually solutions  Cleaning products and vinegar are a solution of base or acid

How do we define and acid and a base?  There are 3 theories as to what acids and bases are.  They are Arrhenius, Bronsted-Lowry, and Lewis Theory.

What is an Acid and Base?(Arrhenius)  An acid is a substance that produces hydrogen ions (H + ) when dissolved in a water solution  Acids contain hydrogen in their chemical formula  These hydrogen ions react with the water molecules and form hydronium ions (H 3 O + )  Any substance that forms hydroxide ions (OH - ) in a water solution is called a base  Most bases will end in hydroxide (OH)

 HCl -> H + (aq) + Cl - (aq)  NaOH -> Na + (aq) + OH - (aq)

Bronsted-Lowry Acids and Bases  Arrhenius definition does not fit the bases of NH 3 and Na 2 CO 3  In Bronsted-Lowry theory, an acid is something that donates protons while a base is something that accepts them.  In this case a H+ and a proton are the same thing.  Everything that is an acid or base under Arrhenius is an acid or base under Bronsted-Lowry

Bronsted-Lowry Acids and Bases  NH 3 + H 2 O -> NH OH -  Which is the acid and which is the base? BASEACID

Conjugate Acids and Bases  NH 3 + H 2 O -> NH OH -  What is is a conjugate acid or base?  A conjugate acid is the particle formed when a base gains a hydrojetn ion.  A conjugate base is the particle that remains when an acid has donated a hydrogen ion  Together, they are a conjugate acid/base pair Conjugate Acid Conjugate Base

Examples  HCl + H 2 O -> H 3 O + + Cl -  H 2 SO 4 + H 2 O -> H 3 O + + HSO 4 ACID BASE CA CB

Lewis Acids and Bases  A Lewis acid is something that accepts electron pairs to form a covalent bond  A Lewis base is something that donates electron pairs to form a covalent bond