Write chemical formulas and names for ionic and covalent compounds and balance chemical equations.

Ionic – composed of two distinct ions Covalent (Molecular) –composed only of nonmetal elements

  Opposite forces attract one another, like forces repel.   Ionic compounds are composed of negative ions and positive ions.   When combined, the number of positive charges must equal the number of negative charges to form a neutral compound.   Example: Na + and Cl - form NaCl   NH 4 + and PO 4 3- form (NH 4 ) 3 PO 4

 Pb 2+ and O 2-  Fe 3+ and O 2-  Chromium (II) and Sulfate  Magnesium and Iodide  Rubidium and Sulfide Fe 2 O 3 PbO CrSO 4 MgI 2 Rb 2 S

 Pb 2+ and O 2-  Fe 3+ and O 2-  Chromium (II) and Sulfate  Magnesium and Iodide  Rubidium and Sulfide Fe 2 O 3 PbO CrSO 4 MgI 2 Rb 2 S Lead(II) Oxide Iron (III) Oxide Chromium (II) Sulfate Magnesium Iodide Rubidium Sulfide

prefixnumber indicated mono-1 di-2 tri-3 tetra-4 penta-5 hexa-6 hepta-7 octa-8 nona-9 deca-10

1. The more metallic element is written first.  Only receives a prefix at the beginning if it contributes more than one atom to the compound.  Ex: NF 3 is Nitrogen trifluoride not Mononitrogen trifluoride. 2.The second element is named by combining: a)a prefix indicating the number of atoms contributed by the element b)The root of the name of the element c)The ending –ide. 3.The 0 or a at the end of a prefix is usually dropped when the name of the element following the prefix starts with another vowel. A singular oxygen is written monoxide not mono-oxide.

  The more metallic element is written first with its subscript as indicated by the prefix.   Dinitrogen is written N 2   The less metallic element is written next with its subscript as indicated by the prefix.   Dinitrogen tetroxide is written N 2 O 4

 Disulfur dichloride  Tetraphosphorus trisulfide  Tetraphosphorus hexoxide  Diarsenic pentoxide  Sulfur Tetrafluoride P4S3P4S3 S 2 Cl 2 P4O6P4O6 As 2 O 5 SF 4

 Cl 2 O 7  P 4 O 10  NCl 3  N 2 F 2  H 2 O Tetraphosphorus decoxide Dichlorine heptoxide Nitrogen trichloride Dinitrogen difluoride Dihydrogen monoxide Water

Name or write the formula for the following: CuCl 2. 2.Iron (III) cyanide 3. 3.N 2 O Oxygen trifluoride 1. 1.Copper (I) chloride 2. 2.Fe(CN) Dinitrogen pentoxide 4. 4.OF 3

Balancing Equations Balancing, Writing, and Naming Equations

Balancing Equations

Law of Conservation of Matter: Law of Conservation of Matter: In a chemical reaction, matter can be neither created nor destroyed. In a chemical reaction, matter can be neither created nor destroyed. In a chemical reaction, the amount of reactants equal the amount of products. In a chemical reaction, the amount of reactants equal the amount of products.

Balancing Equations Law of Conservation of Atoms: Law of Conservation of Atoms: The number of atoms of each type of element must be the same on each side of the equation. The number of atoms of each type of element must be the same on each side of the equation. Remember the diatomic elements: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2. Remember the diatomic elements: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2.

Balancing Equations Hydrogen and oxygen are diatomic elements. Their subscripts cannot be changed. The subscripts on water cannot be changed. Hydrogen + oxygen water Hydrogen + oxygen water H 2 + O 2 H 2 O H 2 + O 2 H 2 O

Balancing Equation Count the atoms on each side. Reactant side: 2 atoms H and 2 atoms O Product side: 2 atoms H and 1 atom O H 2 + O 2 H 2 O H 2 + O 2 H 2 O

Balancing Equations H 2 + O 2 H 2 O H 2 + O 2 H 2 O If the subscripts cannot be altered, how can the atoms be made equal? If the subscripts cannot be altered, how can the atoms be made equal? Adjust the number of molecules by changing the coefficients. Adjust the number of molecules by changing the coefficients.

Balancing Equations Reactants: 2 atoms of H and 2 atoms of O Products: 4 atoms of H and 2 atoms of O H is no longer balanced! H 2 + O 2 2H 2 O H 2 + O 2 2H 2 O

Balancing Equations Reactant side: 4 atoms of H and 2 atoms of O Product side: 4 atoms of H and 2 atoms of O It’s Balanced! 2H 2 + O 2 2H 2 O 2H 2 + O 2 2H 2 O

Balancing Equations Count atoms. Reactants: 2 atoms N and 2 atoms H Products: 1 atom N and 3 atoms of NH 3 N 2 + H 2 NH 3 N 2 + H 2 NH 3 Nitrogen + hydrogen ammonia Nitrogen + hydrogen ammonia

Balancing Equations Nothing is balanced. Nothing is balanced. Balance the nitrogen first by placing a coefficient of 2 in front of the NH 3. Balance the nitrogen first by placing a coefficient of 2 in front of the NH 3. N 2 + H 2 2NH 3 N 2 + H 2 2NH 3

Balancing Equations Hydrogen is not balanced. Hydrogen is not balanced. Place a 3 in front of H 2. Place a 3 in front of H 2. Reactant side: 2 atoms N, 6 atoms H Reactant side: 2 atoms N, 6 atoms H Product side: 2 atoms N, 6 atoms H Product side: 2 atoms N, 6 atoms H N 2 + 3H 2 2NH 3 N 2 + 3H 2 2NH 3

Balancing Equations Count atoms. Reactants: Ca – 3 atoms, P – 2 atoms, O – 8 atoms; H – atoms, S – 1 atom, O – 4 atoms Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4 Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4

Balancing Equations Side note on Ca 3 (PO 4 ) 2 Side note on Ca 3 (PO 4 ) 2 The subscript after the phosphate indicates two phosphate groups. The subscript after the phosphate indicates two phosphate groups. This means two PO 4 3- groups with two P and eight O atoms. This means two PO 4 3- groups with two P and eight O atoms.

Balancing Equations Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4 Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4 Count atoms in the product. Ca atoms – 1, S atom – 1, O atoms – 4; H atoms – 3, P atom – 1, O atoms - 4

Balancing Equations In this equation, the ion groups do not break up. In this equation, the ion groups do not break up. Instead of counting individual atoms, ion groups may be counted. Instead of counting individual atoms, ion groups may be counted. Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4

Balancing Equations Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4 Ca 3 (PO 4 ) 2 + H 2 SO 4 CaSO 4 + H 3 PO 4 Reactants: Ca 2+ – 3, PO , H + – 2, SO Products: Ca , SO , H + - 3, PO

Balancing Equations Balance the metal first by placing a coefficient of 3 in front of CaSO 4. Balance the metal first by placing a coefficient of 3 in front of CaSO 4. Products: Ca – 3 atoms, SO groups Products: Ca – 3 atoms, SO groups Ca 3 (PO 4 ) 2 + H 2 SO 4 3CaSO 4 + H 3 PO 4

Balancing Equations Three sulfate groups are needed on the reactant side so place a coefficient of 3 in front of H 2 SO 4. Three sulfate groups are needed on the reactant side so place a coefficient of 3 in front of H 2 SO 4. 3H 2 SO 4 gives 6 H + and 3 SO H 2 SO 4 gives 6 H + and 3 SO Neither phosphate nor calcium is balanced. Neither phosphate nor calcium is balanced. Ca 3 (PO 4 ) 2 + 3H 2 SO 4 3CaSO 4 + H 3 PO 4

Balancing Equations A coefficient of 2 placed in front of H 3 PO 4 which balances both hydrogen and phosphate. A coefficient of 2 placed in front of H 3 PO 4 which balances both hydrogen and phosphate. Ca 3 (PO 4 ) 2 + 3H 2 SO 4 3CaSO 4 + 2H 3 PO 4

Balancing Equations The sulfate group breaks up. Each atom must be counted individually. Ugh! Reactants: Cu – 1, H – 2, S – 1, O – 4 Products: Cu – 1, S – 1, O - 4, H – 2, O – 1, S – 1, O - 2 Cu + H 2 SO 4 Cu + H 2 SO 4 CuSO 4 + H 2 O + SO 2 CuSO 4 + H 2 O + SO 2

Balancing Equations Sulfur is not balanced. Sulfur is not balanced. Place a two in front of sulfuric acid. Place a two in front of sulfuric acid. Count atoms: 2 H 2 SO 4 H – 4, S – 2, O - 8 Count atoms: 2 H 2 SO 4 H – 4, S – 2, O - 8 Cu + 2H 2 SO 4 CuSO 4 + H 2 O + SO 2

Balancing Equations Hydrogen needs to be balanced so place a 2 in front of the H 2 O. Hydrogen needs to be balanced so place a 2 in front of the H 2 O. Count the number of atoms. Count the number of atoms. Cu + 2H 2 SO 4 CuSO 4 + 2H 2 O + SO 2

Balancing Equations Reactants: Cu – 1, H – 4, S – 2, O – 8 Reactants: Cu – 1, H – 4, S – 2, O – 8 Products: Cu – 1, S – 1, O – 4, H – 4, O – 2, S – 1, O – 2 = Cu – 1, S – 2, H – 4, O – 8 Products: Cu – 1, S – 1, O – 4, H – 4, O – 2, S – 1, O – 2 = Cu – 1, S – 2, H – 4, O – 8 It’s balanced! It’s balanced! Cu + 2H 2 SO 4 CuSO 4 + 2H 2 O + SO 2

Balancing Equations Balancing hints: Balancing hints: Balance the metals first. Balance the metals first. Balance the ion groups next. Balance the ion groups next. Balance the other atoms. Balance the other atoms. Save the non ion group oxygen and hydrogen until the end. Save the non ion group oxygen and hydrogen until the end.

Balancing Equations This method of balancing equations is the inspection method. This method of balancing equations is the inspection method. The method is trial and error. The method is trial and error. Practice. Practice.

Writing and Naming Write the corresponding formula equation and then balance the equation. Nickel + hydrochloric acid Nickel + hydrochloric acid Nickel(II) chloride + hydrogen Nickel(II) chloride + hydrogen

Writing and Naming Write each formula independently. Write each formula independently. Ignore the rest of the equation. Ignore the rest of the equation. Balance the equation after writing the formulas. Balance the equation after writing the formulas. Ni + HCl NiCl 2 + H 2 Ni + HCl NiCl 2 + H 2 Ni + 2HCl NiCl 2 + H 2 Ni + 2HCl NiCl 2 + H 2

Writing and Naming Remember the diatomic elements: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2. Remember the diatomic elements: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2.

Writing and Naming Balance the formula equation. Write the word equation. Cu + H 2 SO 4 Cu + H 2 SO 4 CuSO 4 + H 2 O + SO 2 CuSO 4 + H 2 O + SO 2

Writing and Naming Cu + 2H 2 SO 4 Cu + 2H 2 SO 4 CuSO 4 + 2H 2 O + SO 2 CuSO 4 + 2H 2 O + SO 2 Write the names: Cu by itself is just copper. Copper(I) or copper(II) would be incorrect. H 2 SO 4 should be named as an acid. Sulfuric acid

Writing and Naming CuSO 4 has a SO 4 2- group so Cu must be 2+. Some metals must have Roman Numerals. Copper(II) sulfate CuSO 4 has a SO 4 2- group so Cu must be 2+. Some metals must have Roman Numerals. Copper(II) sulfate H 2 O is known as water. H 2 O is known as water. SO 2 is a nonmetal compound. Its name is either sulfur dioxide or sulfur(IV) oxide. SO 2 is a nonmetal compound. Its name is either sulfur dioxide or sulfur(IV) oxide.

Writing and Naming Copper + sulfuric acid  Copper(II) sulfate + water + sulfur dioxide Cu + 2H 2 SO 4 Cu + 2H 2 SO 4 CuSO 4 + 2H 2 O + SO 2 CuSO 4 + 2H 2 O + SO 2

Balancing Equations Chapter 8 Chapter 8 Practice! Practice!