Chapter 7- Chemical Formulas and Chemical Compounds

1. Chapter 7- Chemical Formulas and Chemical Compounds

2. Ban Dihydrogen Monoxide! • Colorless, odorless, tasteless • Kills uncounted thousands of people every year. • Most deaths caused by accidental inhalation • Prolonged exposure to its solid form causes severe tissue damage. • Symptoms of ingestion can include • excessive sweating and urination, • a bloated feeling, • nausea, • vomiting • body electrolyte imbalance. • For those who have become dependent, withdrawal means certain death.

3. Ban Dihydrogen Monoxide! • Also known as hydroxl acid • Major component of acid rain • Contributes to the "greenhouse effect." • May cause severe burns. • Contributes to the erosion of our natural landscape. • Accelerates corrosion and rusting of many metals. • May cause electrical failures and decreased effectiveness of automobile brakes. • Been found in excised tumors of terminal cancer patients. • Is now an ingredient in most foods and beverages

4. Ban Dihydrogen Monoxide! • Based on the evidence presented in the previous two slides, do you support the banning of dihydrogen monoxide? • Write at least two sentences stating your reasoning. • Please sign the petition!

5. What is Dihydrogen Monoxide?

6. Chemical Formulas • Indicate the relative number of atoms or ions of each kind in a chemical compound C8H18 MgCl2 Ca(OH)2 8 C atoms 18 H atoms 1 Mg2+ ion 2 Cl- ions 1 Ca2+ ion 2 OH- ions

7. Monatomic Ions • Ions formed from a single atom • Usually have noble gas configurations • That’s how we determine its charge • Example: • Li: 1s22s1 • Li+: 1s2 or [He] • Table on p.221 on monatomic ions

8. Naming Monatomic Cations • Use the element’s name! • Yes, it’s that simple! • Example: • Cs+ = cesium • Al3+ = aluminum

9. Naming Monatomic Anions • Drop the ending of the element’s name • Add the ending –ide • Examples: • Cl- = chloride • N3- = nitride

10. Naming Monatomic Ions • K+ • S2- • Rb+ • O2- • I- • Ba2+ • Cu+ • potassium • sulfide • rubidium • oxide • iodide • barium • copper

11. Binary Ionic Compounds • Compounds composed of two ions • Total numbers of positive charges and negative charges must be equal • Examples: • NaCl • KBr • CaF2

12. Writing Binary Ionic Compounds • Write the symbols for the ions side by side. Write the cation first. Al3+ O2- • Cross over the charges to use as the subscript for the other ion. Al3+ O2- Al2 O3

13. Writing Binary Ionic Compounds • Check the subscripts and divide them to give the smallest whole number ratio of ions. Al2O3 • Write the formula! Al2O3

14. Writing Binary Ionic Compounds • Zinc iodide • Barium fluoride • Lithium oxide • Calcium oxide • Magnesium bromide • ZnI2 • BaF2 • Li2O • CaO • MgBr2

15. Naming Binary Ionic Compounds • Give name of cation first • Then name the anion • Al2O3 • Name of cation: aluminum • Name of anion: oxide • Name of compound: aluminum oxide

16. Naming Binary Ionic Compounds • BaI2 • ZnF2 • K2O • MgO • CaBr2 • Barium iodide • Zinc fluoride • Potassium oxide • Magnesium oxide • Calcium bromide

17. Cations With Different Charges • Some elements form two or more cations with different charges • Fe2+ and Fe3+ • Iron (II) and Iron (III) • Naming compounds • FeO and Fe2O3 • Iron (II) oxide and Iron (III) oxide

18. Name the Following Compounds • CuO • CoF3 • SnI4 • FeS • Copper (II) oxide • Cobalt (III) fluoride • Tin (IV) iodide • Iron (II) sulfide

19. Quiz- Name the Following Compounds • K2S • AgBr • Na2O • FeCl2 • BaS Lithium fluoride Silver iodide Iron (III) oxide Magnesium iodide Gold chloride

20. Polyatomic Ions • Ions that contain two or more atoms • Most are negatively charged • List of polyatomic ions is on handout • **MEMORIZE THEM!!!** • Examples: • CN- cyanide • HCO3- hydrogen carbonate (bicarbonate) • NH4+ ammonium

21. Polyatomic Ions • You will need to memorize the following: • Ammonium NH4+1 • Acetate C2H3O2-1 • Hydroxide OH-1 • Nitrite NO2-1 • Nitrate NO3-1 • Bicarbonate HCO3-1 • Carbonate CO3-2 • Chromate CrO4-2 • Sulfate SO4-2 • Phosphate PO4-3

22. Oxyanions • Polyatomic ions that contain oxygen • Name depends on number of oxygen atoms

23. Oxyanions (cont.) • If two oxyanions- • Most oxygens: -ate • Least oxygens: -ite • Example • NO3- : nitrate • NO2- : nitrite

24. Oxyanions (cont.) • If more than two oxyanions • Most oxygens: “Per- …. –ate” • “-ate” • “-ite” • Least oxygens: “Hypo- …. –ite” • Example • ClO4- : perchlorate • ClO3- : chlorate • ClO2- : chlorite • ClO- : hypochlorite

25. Polyatomic Ion Quiz • Sodium hypochlorite • Potassium sulfate • Magnesium peroxide • Ammonium chloride • Lithium nitrate • Potassium phosphate • NaClO • K2SO4 • MgO2 • NH4Cl • LiNO3 • K3PO4

26. Polyatomic Ion Quiz • Bicarbonate • Acetate • Bisulfite • Permanganate • Nitrite • Cyanide • Hydroxide • Bisulfate • Nitrate • What’s your favorite polyatomic ion?

27. Binary Molecular Compounds • Composed of molecules (covalently bonded!) • A nonmetal bonded to another nonmetal • Examples: • SO3 • ICl3 • CH4 • H2O

28. Prefixes for Naming Binary Molecular Compounds • 1 mono- • 2 di- • 3 tri- • 4 tetra- • 5 penta- • 6 hexa- • 7 hepta- • 8 octa- • 9 nona- • 10 deca

29. Naming Binary Molecular Compounds • Which element goes first? • Smaller group number • If same group- greater period number • Use prefix only if there is more than one atom • Second element • Prefix indicating number of atoms + root of the name of the element + -ide • General order of elements in binary compounds: • C, P, N, H, S, I, Br, Cl, O, F

30. Naming Binary Molecular Compounds • Examples: • SO3 – sulfur trioxide • BrCl3 – bromine trichloride • PBr5 – phosphorus pentabromide • N2O5 – dinitrogen pentoxide

31. Naming Binary Molecular Compounds • N2O • CCl4 • NO • CO2 • N2O3 • P4O10 • Dinitrogen monoxide • Carbon tetrachloride • Nitrogen monoxide • Carbon dioxide • Dinitrogen trioxide • Tetraphosphorus decoxide

32. Naming Binary Molecular Compounds- More Practice! • Disulfur dioxide • Silicon tetrafluoride • Sulfur monoxide • Phosphorus trioxide • Boron trifluoride • Diphosphorus pentoxide • S2O2 • SiF4 • SO • PO3 • BF3 • P2O5

33. Acids • Acid- a type of molecular compound • Two types • Binary acids- made up of two elements- hydrogen, and one of the halogens (F, Cl, Br, I) • Oxyacids- contain hydrogen, oxygen, and a third element • Examples • Binary acids: • HCl- hydrochloric acid; HF- hydrofluoric acid • Oxyacids: • H2SO4: sulfuric acid • HNO3: nitric acid

34. Formula Mass • The sum of the atomic masses of all atoms represented in its formula • Units = amu (atomic mass units) • Example: What is the formula mass of water? • 2 H atoms @ 1.01 amu each = 2.02 amu • 1 O atom @ 16.00 amu each = 16.00 amu • Total mass of water = 16.00 + 2.02 = 18.02

35. Formula Mass • Find the formula mass of the following: • KClO3 • H2SO4 • Mg(NO3)2 • C12H22O11

36. Molar Mass • The mass in grams of one mole of a substance • If we have 1 mole of H2O, we have • 2 moles of H atoms • 1 mole of O atoms

37. Molar Mass (cont.) • How many moles of each atom are in the following? • CaCl2 • NaOH • KMnO4 • NH4OH • Mg(NO3)2

38. Molar Mass (cont.) • Once we know the number of moles of each atom, we can calculate the molar mass. • In H2O: • 2 moles H x 1.01 g H = 2.02 g H 1 mole H • 1 mole O x 16.00 g O = 16.00 g O 1 mole O

39. Molar Mass (cont.) • Total mass of 1 mole H2O • 2.02 g + 16.00 g = 18.02 g/mol

40. Molar Mass (cont.) • Determine the molar mass of the following: • CaCl2 • NaOH • KMnO4 • NH4OH • Mg(NO3)2

41. Molar Mass as a Conversion Factor • Can use molar mass as a conversion factor to determine number of moles • How many moles of H2O are in 34.32 g?

42. Molar Mass as a Conversion Factor • How many molecules of NaCl can be found in a sample containing 45.43 g?

43. Molar Mass as a Conversion Factor • How many carbon atoms are in a 23.43 g sample of CO2?

44. Fun With Conversions! • Ibuprofen, C13H18O2, is the active ingredient in Advil. • Find its molar mass • If the tablets in the bottle contain a total of 33 g of ibuprofen, how many moles of ibuprofen are in the bottle? • How many molecules of ibuprofen are in the bottle? • What is the total mass in grams of carbon in 33 g of ibuprofen?