General, Organic, and Biological Chemistry Fourth Edition Karen Timberlake 5.4 Polyatomic Ions Chapter 5 Compounds and Their Bonds © 2013 Pearson Education, Inc. Lectures

© 2013 Pearson Education, Inc. Chapter 5, Section 4 2 A polyatomic ion  is a group of atoms.  has an overall ionic charge. Examples: NH 4 + ammoniumOH − hydroxide NO 3 − nitrateNO 2 − nitrite CO 3 2− carbonatePO 4 3− phosphate HCO 3 − hydrogen carbonate (bicarbonate) Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 3 The names of common polyatomic anions  end in ate. NO 3 − nitratePO 4 3− phosphate  with one oxygen less, end in ite NO 2 − nitritePO 3 3− phosphite  with hydrogen attached, use prefix hydrogen (or bi). HCO 3 − hydrogen carbonate(bicarbonate) HSO 3 − hydrogen sulfite (bisulfite) Some Names of Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 4 Names and Formulas of Common Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 5 Compounds Containing Polyatomic Ions Polyatomic ions  must be associated with an ion of opposite charge.  form ionic bonds with ions of opposite charge to achieve charge balance. Example: Ca 2+ NO 3 − calcium nitrate ion charge balance: Ca(NO 3 ) 2 calcium nitrate

© 2013 Pearson Education, Inc. Chapter 5, Section 4 6 Some Compounds with Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 7 Guide to Naming Compounds with Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 8 Step 1 Identify the cation and polyatomic ion (anion). Cation: K + Anion: SO 4 2− Step 2 Name the cation, using a Roman numeral if needed. K + = potassium ion Step 3 Name the polyatomic ion. SO 4 2− = sulfate ion Step 4 Write the name or the compound, cation first and the polyatomic ion second. K 2 SO 4 = potassium sulfate Name K 2 SO 4

© 2013 Pearson Education, Inc. Chapter 5, Section 4 9 Match each formula with the correct name. 1. MgSA. magnesium sulfite MgSO 3 B. magnesium sulfate MgSO 4 C. magnesium sulfide 2. Ca(ClO 3 ) 2 A. calcium chlorate CaCl 2 B. calcium chlorite Ca(ClO 2 ) 2 C. calcium chloride Learning Check

© 2013 Pearson Education, Inc. Chapter 5, Section 4 10 Match each formula with the correct name. 1. MgSC. magnesium sulfide MgSO 3 A. magnesium sulfite MgSO 4 B. magnesium sulfate 2. Ca(ClO 3 ) 2 A. calcium chlorate CaCl 2 C. calcium chloride Ca(ClO 2 ) 2 B. calcium chlorite Solution

© 2013 Pearson Education, Inc. Chapter 5, Section 4 11 Learning Check Name each of the following compounds. 1.Cu(ClO 3 ) 2 2.PbCO 3 3.Ba 3 (PO 3 ) 2

© 2013 Pearson Education, Inc. Chapter 5, Section 4 12 Solution Name each of the following compounds: 1.Cu(ClO 3 ) 2 2.PbCO 3 3.Ba 3 (PO 3 ) 2 Step 1 Identify the cation and polyatomic ion (anion). cationpolyatomic ion 1. Cu(ClO 3 ) 2 Cu 2+ ClO 3 − 2. PbCO 3 Pb 2+ CO 3 2− 3. Ba 3 (PO 3 ) 2 Ba 2+ PO 3 3−

© 2013 Pearson Education, Inc. Chapter 5, Section 4 13 Solution Name each of the following compounds. 1.Cu(ClO 3 ) 2 2.PbCO 3 3.Ba 3 (PO 3 ) 2 Step 2 Name the cation using a Roman numeral, if necessary. cation name 1. Cu(ClO 3 ) 2 copper(II) 2. PbCO 3 lead(II) 3. Ba 3 (PO 3 ) 2 barium

© 2013 Pearson Education, Inc. Chapter 5, Section 4 14 Solution Name each of the following compounds. 1.Cu(ClO 3 ) 2 2.PbCO 3 3.Ba 3 (PO 3 ) 2 Step 3 Name the polyatomic ion. polyatomic ion 1. Cu(ClO 3 ) 2 chlorate 2. PbCO 3 carbonate 3. Ba 3 (PO 3 ) 2 phosphite

© 2013 Pearson Education, Inc. Chapter 5, Section 4 15 Solution Name each of the following compounds. 1.Cu(ClO 3 ) 2 2.PbCO 3 3.Ba 3 (PO 3 ) 2 Step 4 Write the name or the compound, cation first and the polyatomic ion second. compound name 1. Cu(ClO 3 ) 2 copper(II) chlorate 2. PbCO 3 lead(II) carbonate 3. Ba 3 (PO 3 ) 2 barium phosphite

© 2013 Pearson Education, Inc. Chapter 5, Section 4 16 Guide to Writing Formulas for Compounds with Polyatomic Ions

© 2013 Pearson Education, Inc. Chapter 5, Section 4 17 Write the Formula for Aluminium Hydroxide Step 1 Identify the cation and polyatomic ion (anion). Al 3+ and OH − Step 2 Balance the charges.

© 2013 Pearson Education, Inc. Chapter 5, Section 4 18 Write the Formula for Aluminium Hydroxide Step 3 Write the formula, cation first, using the subscripts from charge balance. Al(OH) 3

© 2013 Pearson Education, Inc. Chapter 5, Section 4 19 Select the correct formula for each. 1. aluminum nitrate A. AlNO 3 B. Al(NO) 3 C. Al(NO 3 ) 3 2. copper(II) nitrate A. CuNO 3 B. Cu(NO 3 ) 2 C. Cu 2 (NO 3 ) 3. iron(III) hydroxide A. FeOHB. FeOH 3 C. Fe(OH) 3 4. tin(IV) hydroxide A. Sn(OH) 4 B. Sn(OH) 2 C. Sn 4 (OH) Learning Check

© 2013 Pearson Education, Inc. Chapter 5, Section 4 20 Select the correct formula for each. 1. aluminum nitrate C. Al(NO 3 ) 3 2. copper(II) nitrate B. Cu(NO 3 ) 2 3. iron(III) hydroxide C. Fe(OH) 3 4. tin(IV) hydroxide A. Sn(OH) 4 Solution

© 2013 Pearson Education, Inc. Chapter 5, Section 4 21 Learning Check Write the formula for each of the following. 1. calcium nitrate 2. iron(II) hydroxide 3. aluminum carbonate 4. copper(II) bromide 5. lithium phosphate

© 2013 Pearson Education, Inc. Chapter 5, Section 4 22 Solution Write the formula for each of the following. 1. calcium nitrateCa 2+, NO 3 − Ca(NO 3 ) 2 2. iron(II) hydroxideFe 2+, OH − Fe(OH) 2 3. aluminum carbonateAl 3+, CO 3 2− Al 2 (CO 3 ) 3 4. copper(II) bromide Cu 2+, Br − CuBr 2 5. lithium phosphateLi +, PO 4 3− Li 3 PO 4