MID-TERM EXAM REVIEW! KEY! Unit 1 Convert the following: 1.) 2.02 x 10 15 mg = g 2.02 x 10 15 mg 1 g = 2.02 x 10 12 g 1000 mg 2.) 1.29 x 10-7 m = cm 1.29 x 10-7 m 100 cm = 1.29 x 10-5 cm 1 m 3.) 13.5 dm 3 = cm 3 13.5 dm 3 (L) 1000 cm 3 (ml) = 13,500 cm 3 1 dm 3 (L) 4.) 1.64 x 10 14 ml = L 1.64 x 10 14 ml 1 L = 1.64 x 10 11 L 1000 ml 5.) What is the mass of a cube of aluminum (density = 2.70 g/cm 3 ) with each side measuring 2.00 cm? 2.70 g/cm 3 = m V = 2.00 cm. 2.00 cm. 2.00 cm = 8.00 cm 3 8.00 cm 3 m = 2.70. 8.00 = 21.6 g A student is determining the density of a U.S. nickel. His data is shown below: # of Mass graduated cylinder and 50 ml water Mass cylinder, water, and Mass Nickels water water and Density of. 15 50.00 g 73.50 g? 50.0 ml 53.0 3.0? 6.) What is the mass of 15? 73.50 g 50.00 g = 23.50 g 7.) What is the density of 15? D = 23.50 g = 7.8 g/ml 3.0 ml Unit 2 * Classify as element, compound, solution, or heterogeneous mixture. 8.) Flat soda solution 9.) Potassium iodide compound 10.) Iodine element 11.) Potassium iodide completely dissolved in water solution 12.) Soil heterogeneous mix. 13.) Chromium element * Classify as chemical or physical changes. 14.) Shredding cheese P 15.) Melting cheese P 16.) Digesting cheese C 17.) Making salt from sodium and chlorine C 18.) Sprinkling salt on french fries P * In what group (give number) are each of the following elements found in the Periodic Table? 19.) alkali metals 1 20.) alkaline earth metals 2 21.) transition elements 3-12 22.) halogens 17 23.) noble gases 18 Unit 3 * Tell scientist who... 24.) Discovered the nucleus? Rutherford 25.) Discovered the neutron? Chadwick 26.) First got ideas about atoms published? Dalton 27.) Discovered electron? Thomson 28.) Said electrons move in fixed paths around nucleus? Bohr * Solve the following: 29.) How many molecules of carbon dioxide (CO 2) are contained in 46.2 grams of CO 2? 46.2 g CO 2 6.022 x 10 23 mcs = 6.32 x 10 23 mcs CO 2 44.0 g
30.) What is the mass (in grams) of 6.92 x 10 23 molecules of Ca(NO 3) 2? 6.92 x 10 23 mcs 164.1 g = 189 g 6.022 x 10 23 mcs Unit 4 31.) Write electron configuration for selenium and calcium. Se: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 4 Ca: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 32.) Draw orbital notation for H.O.E.L. of selenium and calcium. Se: Ca: 33.) Write noble gas configuration for selenium and calcium. Se: [Ar] 4s 2 3d 10 4p 4 Ca: [Ar] 4s 2 34.) Write out the set of four quantum numbers for the last electron added to selenium and calcium. Se: n = 4, l = 1, m = -1, s = -½ Ca: n = 4, l = 0, m = 0, s = -½ 35.) Draw the dot diagram for selenium and calcium. 36.) Identify the H.O.E.L. and # of valence electrons for selenium and calcium. Se: HOEL = 4 valence electrons = 6 Ca: HOEL = 4 valence electrons = 2 Unit 5 * Define the following terms: 37.) Ionization energy: amount of energy needed to remove an electron from an atom 38.) Electronegativity: how much an atom wants to gain an electron 39.) Effective nuclear charge: more protons in the nucleus pull the electrons in the energy levels closer to the nucleus 40.) Shielding effect: inner-shell electrons interfere with the hold the nucleus has on the valence electrons 41.) Which element has an oxidation number of 1? G 42.) Which element is a noble gas? H 43.) Which element(s) is/are metals? A, B 44.) Which element is an alkaline earth metal? B 45.) Which element has 5 electrons in the outer shell? E 46.) Which element(s) are metalloids? C 47.) Give the formula for the compound between A and F. A 2F
* Without looking at the Periodic Table write the expected outer electron configuration for the element in: 48.) Period 2, Group 14 2s 2 2p 2 49.) Period 5, Group 17 5s 2 5p 5 50.) Period 3, Group 2 3s 2 * Answer the following. 51.) Name the most reactive metal. francium 52.) Name the most reactive nonmetal. fluorine Unit 6 * Tell predominant type of bonding in the following compounds (ionic, covalent, both): 53.) CO 2 covalent 54.) Na 2SO 4 both 55.) MgBr 2 ionic 56.) Ag 2CO 3 both * Define and tell what types of substances exhibit these intermolecular forces: 57.) Hydrogen bonding: particularly strong attraction between molecules of NH 3, H 2O, and HF; accounts for unusually high BP of these substances 58.) Dipole-dipole: attraction that polar molecules have for each other 59.) London dispersion: weak intermolecular force that occurs between all molecules; allows for nonpolar substances to exist in liquid form Unit 7 * Write formulas for the following: 60.) Potassium carbonate K 2CO 3 61.) Chromium (III) nitrate Cr(NO 3) 3 62.) Disulfur pentoxide S 2O 5 63.) Zinc sulfide ZnS 64.) Magnesium dichromate MgCr 2O 7 * Name the following compounds: 65.) Na 2CrO 4 sodium chromate 66.) AgBr silver bromide 67.) SO 3 sulfur trioxide 68.) Ca(ClO 3) 2 calcium chlorate 69.) PbSO 4 lead (II) sulfate 70.) Fe(OH) 3 iron (III) hydroxide 71.) Which compound has the highest % nitrogen? (A) NO 2 (B) NaNO 3 (C) NH 3 (A) 14 x 100 = 30.4% N (B) 14 x 100 = 16.5% N (C) 14 x 100 = 82.4% N 46 85 17 * Find the oxidation number of nitrogen in each of these compounds. 72.) Zn(NO 3) 2 (1. +2) + (2. x) + (6. -2) = 0 x = +5 73.) Zn(NO 2) 2 (1. +2) + (2. x) + (4. -2) = 0 x = +3 74.) Mg 3N 2 (3. +2) + (2. x) = 0 x = -3 75.) N 2O 5 (2. x) + (5. -2) = 0 x = +5 76.) What is the empirical formula of a compound containing 56.5 % potassium, 8.7 % carbon, & 34.8 % oxygen? 56.5 g K 1 mole = 1.445 moles K 1.445 = 2 K 2CO 3 39.1 g 0.725 8.7 g C 1 mole = 0.725 moles C 0.725 = 1 12.0 g 0.725 34.8 g O 1 mole = 2.175 moles O 2.175 = 3 16.0 g 0.725
77.) A compound has an empirical formula of CH 2O. If the molar mass of the actual formula is 180 g/mole, what is the molecular formula for the compound? C: 1 x 12.0 = 12.0 180 = 6 C 6H 12O 6 H: 2 x 1.0 = 2.0 30 O: 1 x 16.0 = 16.0 + 30.0 78.) Name Symbol # of p + # of e - # of n o atomic # mass # tin - 118 118 Sn 50 50 68 50 118 iron - 56 56 Fe 26 26 30 26 56 nitrogen - 14 14 N 7 7 7 7 14 silicon - 28 28 Si 14 14 14 14 28 79.) Energy 80.) Wavelength (short/long) High short high Low long low Frequency (high/low) Across a Period (left to right) Down a Group (top to bottom) Atomic Radius decreases increases yes Electronegativity increases decreases no Electron Affinity increases decreases no Ionization Energy increases decreases yes Noble Gases Included? yes or no? 81.) Compound Lewis Structure Class Shape Molecular Polarity H 2O AB2E2 bent polar CF 4 AB4 Tetrahedral nonpolar CO 2 AB2 Linear nonpolar NH 3 AB3E Trigonal Pyramid polar
Back to the Main Page