Acid and Bases continued

Acids reacting with Metals Acids react with metals to produce hydrogen gas Acid + metal  hydrogen gas + _______ Example Hydrochloric acid + zinc  hydrogen gas + zinc chloride HCl (aq) + Zn (s)  H 2 (g) + ZCl 2 (aq)

Acids reacting with carbonates When acids react with carbonate compounds they produce carbon dioxide gas. acid + carbonate  carbon dioxide + ___ + ____ Example: vinegar reacting with baking soda + Acetic acid + sodium hydrogen carbonate  carbon dioxide + water + sodium acetate HC 2 H 3 O 2 (aq) + NaHCO 3 (aq)  CO 2 (g) + H 2 O (l) + NaC 2 H 3 O 2 (aq)

Chemical Formulas of Acids All acids release at least one hydrogen ion (H + ) These H + ions give acids their properties Chemical formulas of acids begin with an H Chemical formulas of acids always have “(aq)” – Acids ONLY SHOW PROPERTIES WHEN DISSOLVED IN WATER Examples HCl (aq) HBr (aq) HF (aq) H 2 S (aq)

Names of Acids Binary Acids – Contain only 2 elements (hence Bi-nary) – Example: H 2 S (aq) is hydrosulfuric acid Oxyacids (related to polyatomic ions) – Same as the related polyatomic ion, but with additional hydrogen ions – Example: phosphoric acid contains phosphate and 3 hydrogen ions H 3 PO 4

Names of Acids Binary Acids Oxyacids Acid Name Chemical Formula HF (aq) hydrofluoric acid HCl (aq) hydrochloric acid HBr (aq) hydrobromic acid H 2 S (aq) hydrosulfuric acid Acid NameChemical Formula HC2H3O2 (aq)Acetic acid HNO3 (aq)Nitric acid H2CO3 (aq)Carbonic acid H2SO4 (aq)Sulfuric acid H3PO4 (aq)Phosphoric acid

Chemical properties of bases Completely separates into its ions as it dissolves in water NaOH (s) dissolve in water  Na + (aq) + OH - (aq) Releases hydroxide OH - ions when dissolved

Chemical formulas and names of bases BaseChemical Formula Sodium hydroxideNaOH (aq) Calcium hydroxideCa(OH) 2 (aq) Ammonium hydroxideNH 4 OH (aq) Magnesium hydroxideMg(OH) 2 (aq) Aluminum hydroxideAl(OH) 3 (aq) Sodium hydrogen carbonate (baking soda) NAHCO 3 (aq)

Acid-Base indicators IndicatorColour in Acid Colour in Base Bromothymol blueYellowBlue PhenolphthaleinColourlessPink Phenol redYellowRed/pink LitmusRedBlue Methyl orangeRedOrange/yellow

The pH Scale Stands for the power of Hydrogen Measure of hydrogen ion (H + ) concentrations More hydrogen ions (H + ), more acidic THEN WHY ARE ACIDS a Lower number!??!?! pH 1pH 2pH 3…pH 10pH 13pH

pH Scale

Acids + Bases When an acid and base are combined they react in a __________________ reaction. Acids donate ______ cations Bases donate ________ anions ________________ is this type of reaction ________________.

Acids + Bases acid + base  water + ionic compound For example… HCl(aq) + KOH(aq)  H 2 O(l) + KCl(aq)

Why is this important? Treating chemical spills – 150’000 L of sulfuric acid in Englehart, Ontario – Treated with calcium oxide

Why is this important? Medicine – Stomach antacids

Acids and metals When an acid reacts with a metal, it produces a compound with the cation of the metal and the anion of the acid, and hydrogen gas. Ex. Hydrochloric acid + zinc  hydrogen gas + zinc chloride