5. Measured quantities, such as length, mass, or time, can best be described as:

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1 1. How many significant figures are there in the number ? a. 7 b. 3 c. 8 d. 4 e The agreement of a particular value with the true value is called a. accuracy. b. error. c. precision. d. significance. e. certainty. 3. How many significant figures are there in the number ? a. 13 b. 5 c. 7 d. 0 e Using the rules of significant figures, calculate the following: a b. 18 c. 17 d. 20 e Measured quantities, such as length, mass, or time, can best be described as: a. sometimes certain. b. always certain. c. always uncertain. d. sometimes uncertain. 6. A titration was performed to find the concentration of hydrochloric acid with the following results: Trial Molarity / / / The actual concentration of HCl was determined to be M; the results of the titration are: a. both accurate and precise. b. accurate but imprecise. c. precise but inaccurate. d. both inaccurate and imprecise. e. accuracy and precision are impossible to determine with the available information.

2 PAGE 2 7. The amount of uncertainty in a measured quantity is determined by: a. both the skill of the observer and the limitations of the measuring instrument. b. neither the skill of the observer nor the limitations of the measuring instrument. c. the limitations of the measuring instrument only. d. the skill of the observer only. 8. The density of gasoline is g/ml at 20 o C. When gasoline is added to water: a. it will float on top. b. it will sink to the bottom. c. it will mix so you can't see it. d. the mixture will improve the running of the motor. e. none of these things will happen. 9. are substances with constant composition that can be broken down into elements by chemical processes. 10. The boiling of water is a 11. A solution is also called a a. Solutions b. Mixtures c. Compounds d. Quarks e. Heterogeneous mixtures a. physical change because the water merely disappears. b. physical change because the gaseous water is chemically the same as the liquid. c. chemical change because heat is needed for the process to occur. d. chemical change because a gas (steam) is given off. e. chemical and physical damage. a. homogeneous mixture. b. heterogeneous mixture. c. pure mixture. d. compound. e. distilled mixture.

3 12. A method of separation that employs a system with two phases of matter, a mobile phase and a stationary phase, is called a. filtration. b. chromatography. c. distillation. d. vaporization. e. homogenization. 13. An example of a pure substance is a. elements. b. compounds. c. pure water. d. carbon dioxide. e. all of these 14. Many classic experiments have given us indirect evidence of the nature of the atom. Which of the experiments listed below did not give the results described? a. The Rutherford experiment proved the Thomson "plum-pudding" model of the atom to be essentially correct. b. The Rutherford experiment was useful in determining the nuclear charge on the atom. c. Millikan's oil-drop experiment showed that the charge on any particle was a simple multiple of the charge on the electron. d. The electric discharge tube proved that electrons have a negative charge. 15. Which of the following statements from Dalton's atomic theory is no longer true, according to modern atomic theory? a. Elements are made up of tiny particles called atoms. b. Atoms are not created or destroyed in chemical reactions. c. All atoms of a given element are identical. d. Atoms are indivisible in chemical reactions. e. All of these statements are true according to modern atomic theory. 16. The first scientist to show that atoms emit any negative particles was a. J. J. Thomson. b. Lord Kelvin. c. Ernest Rutherford. d. William Thomson. e. John Dalton. 17. Which one of the following statements about atomic structure is false? a. The electrons occupy a very large volume compared to the nucleus. b. Almost all of the mass of the atom is concentrated in the nucleus. c. The protons and neutrons in the nucleus are very tightly packed. d. The number of protons and neutrons is always the same in the neutral atom.

4 18. Rutherford's experiment was important because it showed that: a. radioactive elements give off alpha particles. b. gold foil can be made to be only a few atoms thick. c. a zinc sulfide screen scintillates when struck by a charged particle. d. the mass of the atom is uniformly distributed throughout the atom. e. an atom is mostly empty space. 19. Which of the following atomic symbols is incorrect? a. 14 C b. 37 Cl c. P d. 39 K e. 14 N The numbers of protons, neutrons, and electrons in I are: a. 52 p, 128 n, 53 e b. 53 p, 127 n, 54 e c. 53 p, 127 n, 52 e d. 53 p, 74 n, 54 e e. 53 p, 74 n, 52 e 21. Which of the following statements is (are) true? a. 18O and 19F 8 9 have the same number of neutrons. b. 14C and 14N 6 7 are isotopes of each other because their mass numbers are the same. c. 18O 2 8 has the same number of electrons as 20Ne 10. d. both a and b e. both a and c 22. The formula of water, H 2 O, suggests a. there is twice as much mass of hydrogen as oxygen in each molecule. b. there are two hydrogen atoms and one oxygen atom per water molecule. c. there is twice as much mass of oxygen as hydrogen in each molecule. d. there are two oxygen atoms and one hydrogen atom per water molecule. e. none of these 23. Which metals form cations with varying positive charges? a. transition metals b. Group 1 metals c. Group 2 metals d. Group 3 metals e. metalloids

5 24. For which compound does mole weigh 12.8 g? a. C 2 H 4 O b. CO 2 c. CH 3 Cl d. C 2 H 6 e. none of these 25. How many grams are in a 6.94-mol sample of sodium hydroxide? a g b. 278 g c. 169 g d. 131 g e g 26. In balancing an equation, we change the to make the number of atoms on each side of the equation balance. a. formulas of compounds in the reactants b. coefficients of compounds c. formulas of compounds in the products d. subscripts of compounds e. none of these 27. Cortisone consists of molecules, each of which contains 21 atoms of carbon (plus other atoms). The mass percentage of carbon in cortisone is 69.98%. What is the molar mass of cortisone? a g/mol b g/mol c g/mol d g/mol e g/mol 28. Balanced chemical equations imply which of the following? a. Numbers of molecules are conserved in chemical change. b. Numbers of atoms are conserved in chemical change. c. Volume is conserved in chemical change. d. Numbers of molecules are conserved in chemical change and numbers of atoms are conserved in chemical change. e. Numbers of atoms are conserved in chemical change and volume is conserved in chemical change. 29. Given the equation 3A + B C + D, you react 2 moles of A with 1 mole of B. Which of the following is true? a. A is the limiting reactant because of its higher molar mass. b. A is the limiting reactant because you need 3 moles of A and have 2. c. B is the limiting reactant because you have fewer moles of B than A. d. B is the limiting reactant because 3 A molecules react with 1 B molecule. e. Neither reactant is limiting.

6 30. Which of the following pairs is incorrect? a. NH 4 Br, ammonium bromide b. K 2 CO 3, potassium carbonate c. BaPO 4, barium phosphate d. CuCl, copper(i) chloride e. MnO 2, manganese (IV) oxide 31. All of the following are characteristics of nonmetals except: a. poor conductors of electricity b. often bond to each other by forming covalent bonds c. tend to form negative ions in chemical reactions with metals d. appear in the upper left-hand corner of the periodic table e. do not have a shiny (lustrous) appearance TRUE/FALSE 32. The molecular formula always represents the total number of atoms of each element present in a compound. 33. If two separate substances have identical percent composition then the two substances are either identical or isomers. 34. In a balanced equation the mass of reactants is equal to the mass of the products. 35. The product with the fewest moles is the limiting reagent in a chemical reaction.