exam review Che 45465 63gxdg gmistry.pdf
- 3. Evidence of Change What are other possible evidence of chemical changes? ✓Precipitation ✓New Color ✓Heat or light produced ✓Bubbles of gas ✓Change is difficult to reverse
- 4. Periodic Table of Elements Transition Metals Metals Non-metals Metalloids Alkali Metals Alkaline Earth Metals Noble Gases Halogens Hydrogen
- 5. Simplified way of identifying atoms atomic number = # of protons Standard Notation C 12 6 atomic mass = # of protons + # of neutrons # Neutrons = Atomic Mass - Atomic #
- 6. Niels Bohr - electrons orbit the nucleus at specific distances called energy levels Only certain number of electrons fit into each level Bohr-Rutherford Models nucle us 2nd energy level 3rd energy level 1st energy level
- 7. C 12 6 12 - 6 = # of protons # of protons = # of neutrons = # of electrons = 6 = 6 6 6p+ 6no 1st energy level = 2nd energy level = 2 4 3rd energy level = 1st energy level = maximum electrons 2nd energy level = 2 8 8 Bohr-Rutherford Models BR diagrams show # and location of protons, neutrons, and electrons in atoms and ions. Valance electrons= Electrons on the outer orbit.
- 8. Each group/family has an ionic charge It tells you how many electrons must be gained or lost 1+ 2+ Variable charges 3+ 3- 2- 1- 0 Ionic Charges
- 9. Example Neon Magnesium Phosphorus Symbol and ionic charge Metal/non-metal Anion/Cation Ionic Name
- 10. Naming Ions Practice Mg2+ S2- Fe3+ Br- N3- Ca2+ magnesium ion sulfide ion iron ion bromide ion nitride ion calcium ion
- 11. Step 1: Write symbols - metal first & non metal second Step 2: Write ionic charge above each symbol Step 3: Criss cross the numbers - they become subscripts on the opposite element symbol Step 4: Write formula & reduce to lowest terms Ca N CRISS CROSS RULE +2 -3 Ca N +2 -3 Ca N Ca3N2 Ca3N2
- 12. + Li 3 3p+ F 9 9p+ - opposites attract IONIC COMPOUNDS Ionic Bond- Bond that forms between a positive ion (_________) and a negative ion ( _____________). Ionic Compound - form whenever electrons are transferred from a metal to a non-metal The oppositely charged ions attract each other
- 13. Examples Write chemical formula for the following ionic compounds: a) Lead (II) fluoride b) Lead (IV) fluoride Name the following ionic compounds: a) CuF b) CuF2 c) CuO PbF2 PbF4 Copper (I) fluoride Copper (II) fluoride Copper (II) oxide
- 14. Oh! Nick the Camel ate a Clam Supper in Phoenix
- 15. polyatomic ions Polyatomic Ion Ion Formula Ionic Charge Nitrate NO3 - -1 Carbonate CO3 2- -2 Chlorate ClO3 - -1 Sulphate SO4 2- -2 Phosphate PO4 3- -3 Bicarbonate HCO3 - -1 Hydroxide OH- -1 Ammonium NH4 + +1
- 16. names and chemical formulas Step 1: Write symbols, metal first & polyatomic ion second Step 2: Write ionic charge above each symbol Step 3: Criss cross the numbers...using them as subscripts Step 4: Write the formula and reduce to lowest terms Always keep polyatomic ions in brackets!!!
- 17. Let’s practice Write the name and chemical formula for the polyatomic ion shown in the picture: Step 1: Na PO4 Step 2: +1 -3 Na PO4 Step 3: Na3(PO4) Step 4: Na3(PO4) Na3PO4 ` Sodium phosphate
- 18. Let’s practice Write the name and chemical formula for the polyatomic ion shown in the picture: Step 1: Ca SO4 Step 2: +2 -2 Ca SO4 Step 3: Ca2(SO4)2 Step 4: Ca(SO4) CaSO4 calcium sulfate Ca2+
- 19. Let’s practice Write the name and chemical formula for the polyatomic ion shown in the picture: Step 1: Ca NO3 Step 2: +2 -1 Ca NO3 Step 3: Ca(NO3)2 Step 4: Ca(NO3)2 Ca2+ Calcium nitrate
- 20. Writing Chemical formals for Polyatomic ions 1. Calcium nitrate 2. Sodium Carbonate 3. Ammonium Nitride 4. Sodium Phosphate 5. Magnesium Phosphate 6. Ammonium Phosphate 7. Copper (II) Nitrate
- 21. Naming Molecular Compounds The name will include a prefix that will tell us how many atoms of each element are present. The name of the last element will end in “ide”.
- 22. Practice, Practice, Practice! Name the following molecules: a) SF6 b) PCl5 c) NH3 d) N2H4 e) H2S Sulfur hexafluoride Phosphorous pentachloride Nitrogen trihydride Dinitrogen tetrahydride Dihydrogen monosulfide dinitrogen pentoxide carbon monoxide phosphorous trichloride
- 23. A 20g sample of compound A is mixed with 45g of compound B. A chemical reaction occurs in which a gas is produced. Once the reaction is complete, the final product has a mass of 55g. What is the mass of the gas produced? Reactant 1 + Reactant 2 → Product 1 + Product 2 20g 45g + → __ g 65g → 65g + 55g 10
- 24. let’s practice Balance the following equation: ___Ca + ___O2 --> ___Ca O Ca O 1 1 2 1 oxygen is unbalanced 2 2 2 The equation is now balanced 2 2
- 25. let’s practice Balance the following equation: ___N2 + ___H2 --> ___N H3 N H 2 1 2 3 hydrogen is unbalanced 2 2 6 The equation is now balanced 3 6 nitrogen is unbalanced
- 26. let’s practice Balance the following equation: ___Cu2O + ___C --> ___Cu + ___CO2 Cu O 2 1 1 2 oxygen is unbalanced 2 2 The equation is now balanced 2 2 copper is unbalanced C 1 1 4 4 4
- 27. 4 2 2 3 2 2 2 2 2 4 3 2 2 2 2
- 29. ACIDS AND BASES Acid or base pH Scale Indicators
- 30. naming binary acids 1. Use “hydro” as prefix 2. Add stem name of second element 3. Change ending of non-metal to “ic” 4. Follow non-metal’s name with “acid” • For example: • HF(aq) = hydrofluoric acid • HCl(aq) = hydrochloric acid
- 32. Oxyacids Oxyacids - contain three or more elements; hydrogen, oxygen, and one or two other elements They are polyatomic ions that react with hydrogen Example: H2SO4 (aq)
- 33. naming oxyacids 1. Polyatomic ending “ate” is dropped 2. Ending “ic acid” is added to stem name • For example: • HNO3(aq) = 3H+ & NO3 Nitrate Nitric acid H2CO3(aq) = H+ & CO3 - Carbonate Carbonic acid
- 34. Bases always contain hydroxide (OH-) ions or carbonate ions (HCO) Name for bases starts with a metal and ends with hydroxide For example: NaOH = sodium hydroxide NaHCO3 = sodium hydrogen carbonate NAMING BASES
- 35. Naming bases 1. NaOH 2. Ca(OH)2 3. NH4 OH 4. Al (OH)3 1. Sodium hydroxide 2. Calcium hydroxide 3. Ammonium hydroxide 4. Aluminum hydroxide
- 36. magnesium fluoride iron (II) sulfate calcium nitride barium nitrate aluminum iodide FeSO4 Ca3N2. Ba(NO3)2 AlI3