Post Lab Discussion (Exp. 2A)

Heating Curve of Water gas boiling point liquid melting point solid

Heating Curve of Mixture of Water and Alcohol

Conclusion Pure substances change phases at constant temperature. Melting points and boiling points can be used to determine the identity of a substance and whether or not a substance is pure.

Periodic Table: NEED TO KNOW: Symbols & names 1-36 State of elements at room temps. Periods vs. groups (rows) (columns) Metals vs. non-Metals (lose e-) (gain e-) Atomic Number = # of protons Atomic Mass (Mass #) = # of protons + # of neutrons Atomic Radius (page 319 in textbook) Characteristic charges of groups (alkali metals = 1+) Groups: Alkali Metals, Alkaline Earth Metals, Transition Metals, Halogens, Noble Gases

Ionic Compounds (metal + non-metal) Chemistry 11 Unit 3

Lowest common multiple of 2 and 3 is 6 7. Writing Formulas - Ionic Compounds In an ionic compound, positive charges must balance the negative charges. e.g.: What is the formula for magnesium phosphide? Magnesium is Mg2+ Phosphorous is P3- Lowest common multiple of 2 and 3 is 6 3 Mg2+ ions and 2 P3– ions Mg3P2

Mg3P2 CaO Mg2+ P3- Mg2+ P3- Mg2+ 6+ 6- e.g.: What is the formula for calcium oxide? Calcium is Ca2+ Oxygen is O2- 1 Ca2+ ion and 1 O2– ion CaO (remember, the subscript 1 is never written)

Only use if you understand that the + and - charges must balance! Short-cut Only use if you understand that the + and - charges must balance! Magnesium oxide 1. Write both symbols (+ion first) with ion charge 2+ 2- Mg O 2. Criss-cross the charges and write them as subscripts Mg O 2 2 MgO 3. Reduce if possible (remember, the subscript 1 is never written)

Sometimes, metal ions have more than one combining capacity e.g. Cu2+ Cu1+ Fe3+ Fe2+ The name of the compound will include a roman numeral that tells you which combining capacity to use 1+ I 5+ V 2+ II 6+ VI 3+ III 7+ VII 4+ IV e.g. Iron II oxide Iron III oxide 2+ 2- 3+ 2- Fe O Fe O FeO Fe2O3

8. Naming Ionic Compounds 1. Write the name of the metal first. 2. Write the name of the non-metal second, and change the ending to “-ide” 3. ONLY IF THE METAL HAS 2 OR MORE COMBINING CAPACITIES, Include a roman numeral to indicate which one it is. e.g. NaCl Sodium chloride MgF2 Magnesium fluoride 1+ Cu CuCl2 copper has 2 ions: 2+ Cu which one is it?

9. Predicting Ion Charges from Formulas To find out which copper ion it is, look at the charge on the anion and balance the charges in reverse. CuCl2 2+ 1- Cu Cl from periodic table 1- Cl 2- Therefore it is copper II chloride CuCl therefore must be copper I chloride

Practice: Name and write the formulas for: a) chlorine & aluminum Aluminum chloride; AlCl3 b) bromine & sodium Sodium bromide; NaBr c) magnesium & sulphur Magnesium sulphide; MgS d) calcium & nitrogen Calcium nitride; Ca3N2 e) fluorine & beryllium Beryllium fluoride; BeF2

More Practice: Name and determine the charge on each of the transition metals in the following compounds: a) CuO Copper II oxide; Cu2+ b) FeAs Iron III arsenide; Fe3+ c) CrBr3 Chromium III bromide; Cr3+ d) Cu2O Copper I oxide; Cu+ e) FeCl3 Iron III chloride; Fe3+ f) CrCl2 Chromium II chloride; Cr2+

10. Writing Formulas: Polyatomic Ions Some groups of atoms act as individual ions Ion Charge e.g. SO4-2 Sulphate ion -2 OH-1 Hydroxide ion -1 PO4-3 Phosphate ion -3 When writing formulas and naming, pretend the polyatomic ion is just one atom and follow the rules as usual. +1 -3 e.g. K PO4 Potassium phosphate K3PO4 Don’t change the endings of polyatomic ions

More Examples! Al SO4 Al2(SO4)3 Cu SO4 CuSO4 Aluminum sulphate +3 -2 Al SO4 Al2(SO4)3 Aluminum sulphate Put brackets around the SO4 to indicate 3 sulphate ions, not 43 oxygen atoms +2 -2 Cu SO4 CuSO4 Copper (II) sulphate Don’t forget the roman numeral since copper has more than one combining capacity See the back of your periodic table for the names and formulas of important polyatomic ions.

11. Naming Hydrates CuSO4 • 5H2O FeSO4 • 6H2O Hydrates are ionic compounds with water molecules attached e.g. CuSO4 • 5H2O - each copper II sulphate is attached to 5 water molecules Copper II sulphate pentahydrate e.g. Iron II sulphate hexahydrate FeSO4 • 6H2O

12. Names of Common Acids HCl Hydrochloric acid HF Hydrofluoric acid HNO3 Nitric acid HNO2 Nitrous acid H2SO4 Sulphuric acid

Hydro, -IC or -OUS? If the anion name ends in ide: the acid name starts with hydro and ends with ic acid. eg: HCl: Cl- is chloride. So HCl is hydrochloric acid. If the anion name ends in ate: the acid name ends with ic acid; no hydro prefix. eg: HNO3: NO3- is nitrate. So HNO3 is nitric acid. If the anion name ends in ite: the acid name ends with ous acid; no hydro prefix. eg: HNO2: NO2- is nitrite. So HNO2 is nitrous acid.

13. Binary Compounds of Non-Metals Compounds composed of two non-metal elements More metallic name comes first, then use a prefix to show the number of atoms of the less metallic element, followed by the –ide ending Name the following compounds: a) CO2 Carbon dioxide b) CO Carbon monoxide c) PCl3 Phosphorous trichloride d) CCl4 Carbon tetrachloride e) PF5 Phosphorous pentafluoride f) H2O Dihydrogen monoxide a) S2O4 Disulphur tetraoxide

Assignment Homework: “Naming & Formula I” Worksheet Quiz on Periodic Table next class