Salts Containing Polyatomic Ions Acids Oxyacids HW: Read 4-4 &4-6 Do problems 32, 34, 47, & 48 on pgs

 Polyatomic Ions are groups of more than one atom that are bonded covalently, and have a net charge.  There are several polyatomic ions that whose names and formulas MUST be memorized.  They are found on table 4-2 on page 122.  This website may also be helpful… mpounds/polyatomic.shtml

 Polyatomic ions are found in nonbinary ionic compounds, and in oxyacids.  To name a polyatomic Ion in an ionic compound: If the poly atomic ion is first, and the anion is monoatomic, name the polyatomic ion, then name the anion as usual, replacing its ending with the suffix –ide. If the polyatomic ion is second, first name the cation as a type I or type II depending on what it is, including the roman numerals for type II, then name the polyatomic ion. If both cation and anion are polyatomic, just name each polyatomic ion in the order in which they occur.

 Na 2 SO 4  Fe(NO 3 ) 3  Na 2 SO 3  KH 2 PO 4  Mn(OH) 2  NH 4 ClO 3  Sodium sulfate  Iron (III) Nitrate  Sodium Sulfite  Potassium Dihydrogen Phosphate  Manganese (II) Hydroxide  Ammonium Chlorate

 Ca(OH) 2  Na 3 PO 4  KMnO 4  (NH 4 ) 2 Cr 2 O 7  Co(ClO 4 ) 2  KClO 3  Cu(NO 2 ) 2  Calcium Hydroxide  Sodium Phosphate  Potassium Permanganate  Ammonium Dichromate  Cobalt (II) Perchlorate  Potassium Chlorate  Copper (II) Nitrate

 There are several definitions of acids.  For now, an acid is a compound whose formula starts with hydrogen.  There are two types of acids: 1. Regular Acids 2. Oxyacids

 Regular Acids are binary compounds containing hydrogen and one other nonmetal.  The hydrogen will always come first. Examples: HCl, H 2 S, H 3 N  How do you tell how many H’s the acid of a nonmetal will have? Balance the known charge of the nonmetal by adding Hydrogen (each H = 1+ charge).

 Naming Regular Acids 1. Use the prefix Hydro- 2. Use the nonmetal’s root 3. Use the suffix –ic 4. Finish with the word acid.  Hydro-”root”-ic Acid HCl = Hydrochloric Acid H 2 S = Hydrosulfuric Acid H 3 N = Hydronitric Acid

 HF  HI  HBr H2OH2O  H 2 Se  H 3 As H3PH3P  Hydrofluoric Acid  Hydroiodic Acid  Hydrobromic Acid  Hydroxic Acid  Hydroselenic Acid  Hydroarsenic Acid  Hydrophosphoric Acid

 Oxyacids contain hydrogen, oxygen, plus one other nonmetal..  The hydrogen comes first.  The oxygen and other element make up a polyatomic anion called an oxyanion. Example: ClO 4 -, CO 3 2-, NO 3 -, NO 2 -, etc…  Remember you add the number of hydrogen atoms needed to balance the charge on the oxyanion.

 Oxyacids are named using the oxyanions from which they are made.  If the oxyanion ends in –ate, then the suffix is changed to –ic, followed by the word acid. HNO 3 contains nitrate (NO 3 - ): it is called nitric acid  If the oxyanion ends in –ite, then the suffix is changed to –ous, followed by the word acid. HNO 2 contains nitrite (NO 2 - ): it is called nitrous acid

 H 2 SO 4  H 2 SO 3  H 3 PO 4  H 2 CO 3  HClO  HC 2 H 3 O 2  HCN  Sulfuric Acid  Sulfurous Acid  Phorphoric Acid  Carbonic Acid  Hypochlorous Acid  Acetic Acid  Hydrocyanic Acid