Name CHEM 1364 Test #1 (Form A) Spring 2010 (Buckley) If you get stuck on one item, just go to the next and come back later. Point possibilities are indicated in parentheses to the right of each problem number. Be sure to show you work on numerical problems when requested to receive full credit. 1. (6 points) Refer to the figure below as you answer the following questions. Notice each box has a letter either above (top row) or below (bottom row). The three differently filled in spheres white, vertical lines, and black represent atoms of different elements. (a) (b) (c) (d) (e) (f) Give the letter of each box that fits the following descriptions. Notice that each description may have more than one letter and each letter may be used more than once. Write none if none of the boxes fit the description. A pure substance: A mixture of two elements A pure compound: A mixture of two compounds A mixture of an element and a compound Which box could represent a sample of pure oxygen? 2. (4 points) A match is lit and held under a cold piece of metal. The following observations are made. Classify each observation as to whether it is due to a chemical change or a physical change. a. The metal gets warmer b. Soot (carbon) is deposited on the metal c. Water condenses on the metal d. The match burns
3. (3 points) List the following units in size from smallest to largest. decimeter, kilometer, meter, centimeter, millimeter 4. (10 points) Make the following conversions. a. 4.20 cm = km b. 81.3 ml = L c. 5.13 10-7 kg = mg d. 0.0047 cm 3 = mm 3 e. 3.56 gallons = ml (Note: 1 gallon = 4 quarts; 1 qt = 0.946 L) 5. (10 points) Two rectangular blocks are on a table top. One has dimensions of 1.0 cm 3.5 cm 5.0 cm and is made of iron. The other is 5.5 cm 30 cm 42 cm and is made of balsa wood. The density of iron is 7.9 g/cm 3 and the density of balsa wood is 0.16 g/cm 3. SHOW YOUR WORK AS YOU ANSWER THE QUESTIONS BELOW. a. Which block has the larger volume? b. Which block has the larger mass? c. Substance A will float in Substance B if the density of Substance B is less (should have been more) than that of Substance A. Which of these blocks, if either, will float in water? d. If one of these blocks is floating in water and is cut in half, will each half still float in water? Explain your answer.
6. (6 points) Complete the following table. The boxes with dark borders require answers. Symbol: 56 25 Mn 30 3 15 P 88 2 38 Sr + Protons 49 Neutrons 67 Mass Number 30 Electrons 46 7. (6 points) Consider the following listing of special areas on the periodic table. a. Representative elements b. Transition elements c. Inner Transition elements d. Halogens e. Noble gases f. Chalcogens g. Alkaline-earth metals h. Alkali metals i. Metal j. Nonmetal Use the letters above to indicate all categories to which each element below belongs. Note that more than one letter may be used for each element. Tc Ba Br Xe Sm 8. (10 points) Write formulas for and name compounds formed from the following elements and ions. Elements Formula Name a. Ba and P b. NH 4 + and S c. Cs and F d. Cu 2+ and NO 3 - e. Al and O
9. (3 points) Name each of the following compounds. Compound Name a. PCl 5 b. SO 2 c. N 2 O 4 10. (5 points) Write formulas for the following compounds. Compound Name calcium nitrate ammonium phosphate lead (IV) sulfide iodine pentafluoride strontium fluoride Formula
1+ 2+ 3+ Some Common Ions Positive Negative Li + Lithium Cu + Copper (I) or Cuprous F - Fluoride ClO - Hypochlorite Na + Sodium Hg2 2+ Mercury (I) or Cl - Chloride ClO2 - Chlorite Mercurous K + Potassium Ag + Silver Br - Bromide ClO3 - Chlorate Rb + Rubidium NH4 + Ammonium I - Iodide ClO4 - Perchlorate 1- Cs + Cesium NO3 - Nitrate IO4 - Periodate H + Hydrogen NO2 - Nitrite OH - Hydroxide C2H3O2 - Acetate SCN - Thiocyanate MnO4 - Permanganate HCO3 - Hydrogen Carbonate or Bicarbonate CN - Cyanide O2 2- Peroxide H - Hydride Mg 2+ Magnesium Cu 2+ Copper (II) or Cupric Ca 2+ Calcium Hg 2+ Mercury (II) or Mercuric Sr 2+ Strontium Sn 2+ Tin (II) or Stannous O 2- Oxide S 2- Sulfide SO4 2- Sulfate SO3 2- Sulfite CO3 2- Carbonate C2O4 2- Oxalate Ba 2+ Barium Zn 2+ Zinc 2- CrO4 2- Chromate Cr2O7 2- Dichromate Fe 2+ Iron (II) or Ferrous Pb 2+ Lead (II) or Plumbous Cd 2+ Cadmium Mn 2+ Manganese (II) or Manganous Cr 2+ Chromium (II) or Chromous Co 2+ Cobalt (II) or Cobaltous Al 3+ Aluminum As 3+ Arsenic Cr 3+ Chromium (III) or Chromic Fe 3+ Iron (III) or Ferric Co 3+ Cobalt (III) or Cobaltic 3- S2O3 2- Thiosulfate N 3- Nitride P 3- Phosphide PO4 3- Phosphate PO3 3- Phosphite AsO4 3- Arsenate AsO3 3- Arsenite BO3 3- Borate
How many different elements (not atoms elements) are in the compound? Exactly two More than two What types of elements are they? Metal-nonmetal Nonmetal-nonmetal (Ionic compound) Metal keeps its name. For Groups 1 and 2, Al, Zn, and Ag no modification is necessary. For other metals, use a Roman numeral in parentheses to indicate the charge on each ion of the metal. Nonmetal changes its ending to ide. (Molecular or covalent compound) First element retains its name. Second element switches to ide ending. Each name is preceded by a prefix indicating the number of its atoms (di-, tri-, tetra-, etc.). Monois only used for the second element. Metal keeps its name. For Groups 1 and 2, Al, Zn, and Ag no modification is necessary. For other metals, use a Roman numeral in parentheses to indicate the charge on each ion of the metal. Polyatomic ions retain their names.