Mid-Term Test

Mid-term ~ Honors Chemistry

1) The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms? A. 5.5 × 108 kg B. 5.5 × 105 kg C. 5.5 × 10-4 kg D. 5.5 × 10-6 kg E. 5.5 × 10-1 kg

2) Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units.

A. 105.2 g/cm3 B. 105.2 g/cm2 C. 105.2 g/cm D. 72.13 g/cm2 E. 72.13 g/cm

3) Express 96,342 m using 2 significant figures. A. 9.60 × 104 m B. 9.6 × 104 m C. 9.60 × 10-4 m D. 9.6 × 10-4 m E. 96000. m

4) Who is credited with first measuring the charge of the electron? A. Dalton B. Gay-Lussac C. Thomson D. Millikan E. Rutherford

5) Which of the following is a metalloid? A. carbon, C B. sulfur, S C. germanium, Ge D. iridium, Ir E. bromine, Br

6) The substance, CoCl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name? A. cobalt dichloride B. cobalt(II) chloride C. cobalt chloride D. cobaltic chloride E. copper(II) chloride

7) Which one of the following combinations of names and formulas of ions is incorrect? 2- 2+ -1 -1 -1 A. O oxide B. Cd cadmium C. ClO3 chlorate D. HCO3 hydrogen carbonate E. NO2 nitrate

8) Calcium fluoride, CaF2, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass. A. 118.15 g/mol B. 99.15 g/mol C. 78.07 g/mol D. 59.08 g/mol E. 50.01 g/mol

9) Calculate the molar mass of Ca(BO2)2·6H2O. A. 273.87 g/mol B. 233.79 g/mol C. 183.79 g/mol D. 174.89 g/mol E. 143.71 g/mol

10) Sodium bromate is used in a mixture that dissolves gold from its ores. Calculate the mass in grams of 4.68 mol of sodium bromate. A. 706 g B. 482 g C. 383 g D. 32.2 g E. 0.0310 g

11) Lead (II) nitrate is a poisonous substance that has been used in the manufacture of special explosives and as a

sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO3)2. A. 107 g B. 90.8 g C. 87.0 g D. 83.4 g E. 62.6 g 12) Which of the following is a correct set of quantum numbers for an electron in a 5f orbital?

A. n = 5, l = 3, ml = +1 B. n = 5, l = 2, ml = +3 C. n = 4, l = 3, ml = 0 D. n = 4, l = 2, ml = +1 E. n = 5, l = 4, ml = 3

13) Which of the following ions will be most likely to form when selenium ionizes? A. Se6+ B. Se4+ C. Se2+ D. Se2- E. Se4-

14) Select the element whose Lewis symbol is correct.

A. a. B. b. C. c. D. d. E. e.

15) Select the correct formula for a compound formed from calcium and chlorine.

A. CaCl B. CaCl2 C. Ca2Cl D. Ca2Cl2 E. CaCl3

16) Arrange aluminum, nitrogen, phosphorus and indium in order of increasing electronegativity (smallest to largest). A. Al < In < N < P B. Al < In < P < N C. In < Al < P < N D. In < P < Al < N E. None of these orders is correct.

17) The appropriate number of significant figures in the result of 15.234 × 15.208 is A. 2 B. 3 C. 4 D. 5 E. 6

18) Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride? A. 43.3 g B. 62.3 g C. 74.5 g D. 92.9 g E. 107 g

19) Select the best statement. A. Physical changes may be reversed by changing the temperature. B. Physical changes alter the composition of the substances involved. C. Physical properties are not valid characteristics for identifying a substance. D. Physical properties are mostly extensive in nature. E. Physical changes are usually accompanied by chemical changes.

20) Select the best statement. A. Chemical changes provide the only valid basis for identification of a substance. B. Chemical changes are easily reversed by altering the temperature of the system. C. Chemical changes always produce substances different from the starting materials. D. Chemical changes are associated primarily with extensive properties. E. Chemical changes are accompanied by changes in the total mass of the substances involved.

21) Which of the following is a chemical change? A. boiling of water B. melting wax C. broiling a steak on a grill D. condensing water vapor into rainfall E. carving a piece of wood

22) If the price of gold at the morning fixing in London was $5310 per lb, what would a kilogram of gold have cost in £ (pounds)? (Assume an exchange rate of $1.00 = £0.545) A. £1310 B. £3510 C. £6370 D. £10400 E. £17100 E. none of these choices is correct

23) Who is credited with discovering the atomic nucleus? A. Dalton B. Gay-Lussac C. Thomson D. Millikan E. Rutherford

24) Rutherford bombarded gold foil with alpha (α) particles and found that a small percentage of the particles were deflected. Which of the following was not accounted for by the model he proposed for the structure of atoms? A. the small size of the nucleus B. the charge on the nucleus C. the total mass of the atom D. the existence of protons E. the presence of electrons outside the nucleus

25) Lithium forms compounds that are used in dry cells and storage batteries and in high-temperature lubricants. It has two naturally occurring isotopes, 6Li (isotopic mass = 6.015121 amu) and 7Li (isotopic mass = 7.016003 amu). Lithium has an atomic mass of 6.9409 amu. What is the percent abundance of lithium-6? A. 92.50% B. 86.66% C. 46.16% D. 7.503% E. 6.080%

26) A column of the periodic table is called a A. group B. period C. isotopic mixture D. pillar E. shell

27) Although the periodic table is organized according to the atomic numbers of the elements, chemists are more interested in the arrangement of the electrons for their studies. Which of the following statements about the electron configurations and their quantum numbers is correct? A. The size of an atom is associated with the angular momentum quantum number. B. The valence electrons of atoms in a particular group have the same principal and angular momentum quantum numbers. C. The valence electrons of atoms in a particular group have the same angular momentum quantum number but have different principal quantum numbers. D. Quantum numbers for the electrons tell us little about the relative energies of the electrons. E. None of these statements is correct.

28) The smallest ionization energies are found in the ______region of the periodic table. A. upper right B. upper left C. lower right D. lower left E. transition element (d-block)

Correct Answers:

1. C 2. C 3. B 4. D 5. C 6. B 7. E 8. C 9. B 10. A 11. C 12. A 13. D 14. B 15. B 16. C 17. D 18. E 19. A 20.C 21. C 22. C 23. E 24. C 25. D 26. A 27. C