3.2 Acid and Bases

Acids and their properties An acid is any compound that increases the number of hydronium ions –Hydronium forms when and H+ separates from an acid and bonds with water = H 3 O+

Sour Acids have a Sour Taste Lemon, limes, and other citric fruit = Sour Many acids are corrosive = destroy body tissue, clothing, and many other things. Most acids are poisonous

Acids change colors in indicators A substance that changes color in the presences of an acid or base is called an indicator. Water and Turns yellow = ACID Bromthymol blue

Acids react with metals Acids and metals = H+ gas 2HCl + Zn  H 2 + ZnCl 2 (What type of reaction did you learn this was? AB + C  A + CB)

Acids conduct electric current Acids in water produce ions These ions allow the solution to conduct electricity. Like in this car battery.

Uses of Acids Sulfuric Acid –Help make paper –Paint –Detergents –fertilizers Hydrochloric acid –Swimming pool sanitizer –In your stomach— digests food Hydrofluoric Acid Etch glass

Uses of Acids Citric Acid & Ascorbic Acid (vitamin C) –Orange Juice Carbonic acid phosphoric acid Help give flavor to soft drinks

Bases and their properties A base is any compound that increases the number of hydroxide ions (OH-) when dissolved in water. Example: NaOH  Na+ + OH- in water

Bases Bases have a bitter flavor Bases have a slippery feel –Example: Soap Be careful, many bases are corrosive!

Bases

Bases change color in indicators Bromthymol Blue + a base  Dark Blue

Bases Because bases increase OH- ions, bases are conductors of electric currents.

Uses of bases NaOH –Make soap –Paper –Oven cleaner –Unclog sinks Magnesium Hydroxide/Aluminum Hydroxide antacids

Universal Indicator a pH indicator tells us if a solution is an acid 1-6.9, Neutral 7, or Basic pH scale depends on H+ concentration