Answer all questions on the scantron by filling in the bubble completely. Scantrons will not be regraded.

Transcription

1 Quiz 1 Answer all questions on the scantron by filling in the bubble completely. Scantrons will not be regraded. 1. Scientific theories are tested and validated with experimentation. A)True B) False 2. The statement Osmium has a density of 22.9 g/cm 3 is an example of A) law B) hypothesis C) theory D) observation 3.What is the standard SI unit for length? A) mile B) centimeter C) foot D) meter 4. How many significant figures are in ? A) 3 B) 5 C) 6 D) 8 E) 9 5. Convert 3.23 x 10 3 to decimal notation. A) 3.23 B) 32.3 C) 323 D) E) Rounded correctly, the product of: cm X 10.0 cm is A) cm 2 B) 20.0 cm 2 C) 20 cm 2 D) cm 2 E)none of the above 7. Rounded correctly, the result of: ( g g) / (25.10 ml ml) is: A) g/ml B) 11 g/ml C) g/ml D) 11.0 g/ml 8. Total U.S farmland occupies 954 million acres. How many sq miles is this? [1 acre = 43,560 ft 2, 1 mi = 5280 ft] A) 1.16 X mi 2 B)1.49X10 6 mi 2 C)6.11X10 11 mi 2 D)7.87X10 9 mi 2 9. Which of the following is a frequently used unit for the density of liquids and solids? A) g/l B) g/kg C) kg/l D) cm 3 /ml E) g/cm Calculate the mass of lead cube, which has a density of 11.4 g/ml and displaces 20.1 ml of water? A) 230 g B) 229 g C)229.2 g D) 1.76 g

2 11. The length of a piece of glass tubing is m. How many inches long is the tubing? [2.54 cm = 1 inch] A) inches B) inches C)20.7 inches D) 52.5 inches E)none of the above 12. What is the density of a sample of mineral oil if 250 ml has a mass of 0.23 kg? A) g/ml B)0.92 g/ml C)5.8 g/ml D)10.9 g/ml Quiz 2 PART A: MULTIPLE CHOICE 1. Which state of matter has indefinite shape and is compressible? A) liquid B) solid C) gas D) plasma 2. A salt (NaCl) solution is an example of a (an) A) pure substance B) element C) compound D) homogeneous mixture E) heterogeneous mixture 3. Which of the following items is a chemical property? A) the paint color on a new red car B) the odor of spearmint gum C) the melting and boiling point D) the tarnishing of a copper statue 4. Convert 95.0 kwh to (food) Calories. ( 1 cal = J and 1 kwh = 3.60 x 10 6 J.) A) 8.17 x 10 3 Cal B).8.17 x 10 4 Cal C) 8.17 x 10 7 Cal d) 1.43 x 10 7 Cal E) 1.43 x 10 9 Cal 5. Which of the following elements will have the most similar chemical properties as potassium?

3 A) Ca B)Ar C)Fe D)Na E)C A) Electron B) Neutron C) Proton D) two of the above E) all of the above 6. Which of the following subatomic particles has the least mass? 7. The names of the elements whose symbols are Si, P, Mg, S are respectively: A) silicon, potassium, magnesium, and sulfur B) silver, phosphorus, magnesium, and sulfur C) silicon, phosphorus, manganese, and sulfur D) silicon, phosphorus, magnesium, and sulfur E) silicon, phosphorus, magnesium, and sodium 8. Which one of the following is a period 3, group 4A metalloid? A) B B) Si C) Ge D) P 9. The nucleus of a 19 9F atom contains: A)19 protons and 19 electrons B)19 protons and 0 electrons C) 9 protons and 10 electrons D) 19 protons and 19 neutrons E) 9 protons and 10 neutrons 10. What is the symbol of an ion that has 12 protons and 10 electrons? A) Si 2+ B) Si C) Mg 2+ D) Ne E) Ne How many electrons are in the bromide ion, Br? A) 35 B) 36 C) 46 D) 70 E) 8 PART B : SHOW ALL WORK IN THE SPACES PROVIDED. USE UNITS AND SIGNIFICANT FIGURES IN YOUR CALCULATIONS. CIRCLE YOUR FINAL ANSWER.

4 1. Calculate the quantity of heat required to raise the temperature of a ml cup of coffee by 75.1 o C. Density of coffee is 1.00 g/ml and specific heat of coffee is J/g. o C. 2. Carbon has three naturally occurring isotopes: C-12 with mass amu and a natural abundance of 98.89%, C-13 with mass amu and a natural abundance of 1.110%, and C- 14 which is negligibly small (assume 0% abundance). Calculate the atomic mass of carbon. Quiz 3 Mark your choices on the scantron by filling in the bubbles clearly using a pencil. Erase your changes completely. Scantrons cannot be regraded. Write your name and section number on the scantron. 1. The limiting reactant is always the reactant with the least mass 2. According to the following reaction, 2 moles of hydrogen gas react with one mole of oxygen gas to produce 2 moles of water. 2H2 + O2 2H2O 3. Assuming that temperature and pressure are constant, the volume of a gas is inversely proportional to the number of moles. 4. At approximately room temperatures and pressures, real gases will follow the model of kinetic molecular theory and behave as ideal gases. 5. STP conditions are 273 K and 760 mm Hg. 6. Determine the excess reactant for the reaction below, if you start with 10.0 g of Na and 10.0 g of Cl 2? 2Na + Cl2 2NaCl A) Na B) Cl 2 C) NaCl D) both Na and Cl 2 7. Calculate the actual yield (in grams) of a reaction if 28.4 grams is the maximum amount produced from a reaction that has 88.0% yield? A) 25.0 B) 22.0 C) 3.52 D) 352

5 8. All of the following statements are consistent with the kinetic molecular theory of gases EXCEPT A) The size of the gas molecules is negligible compared to the total volume of the gas. B) Gases have a low density because there is so much empty space between the particles. C) The gas molecules collide with each other and with the surfaces around them. D) Strong attractive forces hold the gas molecules together. E) Gases assume the shape and volume of their container because they are in constant, straightline motion. 9. A 3.76 g sample of an inert gas is stored in a 2.00 L vessel at 874 torr and 25 C. Calculate the molar mass of the gas? A) 4.00 B) 20.2 C) 40.0 D) 32.0 E) not enough information 10. Oxygen gas reacts with powdered aluminum according to the following reaction. 4Al + 3O2 2Al2O 3 Calculate how many liters of O 2 gas, measured at 782 mm Hg and 25 o C, are required to completely react with 64.8 g of Al? A) 22.4 L B) 42.8 L C) 45.4 L D) 21.0 L E) not enough information 11. A sealed container contains 1.0 mol of hydrogen and 2.0 moles of nitrogen gas. If the total pressure in the container is 1.5 atm, what is the amount of pressure exerted by each gas?

6 A) H 2 = 1.0 atm and N 2 =.50 atm B) H 2 = 0.50 atm and N 2 = 1.0 atm C) H 2 = 1.0 atm and N 2 = 2.0 atm D) H 2 = 2.0 atm and N 2 = 1.0 atm E) not enough information

7 Chem 25; W10_Lecture Quiz 1 Name 7