mid1a_f03 - Avogadro's Number, NA = 6.022 1023 1. [7...

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A = 6.022 × 10 23 1. [7 points] Which of the following statements is true ? (a) Air is an element (b) Air is a compound (c) Air is a heterogeneous mixture (d) Air is a homogeneous mixture (e) Air is a pure substance 2. [7 points] What is the empirical formula of the ionic compound that forms between calcium and iodine? (a) Ca 3 I 2 (b) Ca 2 I (c) CaI (d) CaI 2 (e) None of the above 3. [7 points] Which of the following pairs of atoms (ions) have the same number of neutrons ? (a) 65 Zn 2+ and 67 Ge (b) 87 Sr 2+ and 83 Kr (c) 16 O 2- and 19 F (d) 57 Fe 3+ and 55 Fe 2+ (e) None of the above pairs have the same number of neutrons 4. [7 points] What is the empirical formula of potassium sulfite? (a) PSO 3 (b) KSO 4 (c) K 2 SO 4 (d) K 2 SO 3 (e) K 2 S 5. [7 points] How many carbon atoms are present in a single 2.00 ounce shot of pure ethanol (C 2 H 5 OH, density = 0.789 g/cm 3 )? [1 ounce = 29.6 mL] (a) 6.11 × 10 23 (b) 1.22 × 10 24 (c) 1.96 × 10 24 (d) 1.20 × 10 23 (e) None of the above
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6. [7 points] You are given a solid yellow crystal of unknown composition. After running a series of tests you make the following observations: (a) the crystal is an electrical insulator, (b) if you strike the crystal with a hammer it cracks in several places, (c) if you put the crystal in a beaker of water it dissolves and the resulting solution is found to be a good conductor of electricity. Which of the following substances could have properties consistent with these observations (a) Sulfur (S) (b) Gold (Au) (c) Sodium Chromate (Na 2 CrO 4 ) (d) Carbon tetrachloride (CCl 4 ) (e) None of the above choices could have the described properties 7. [7 points] Which of the following statements is false ? (a) Silicon is a metalloid
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This note was uploaded on 07/17/2008 for the course CHEM 121 taught by Professor Wyzlouzil during the Fall '07 term at Ohio State.

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mid1a_f03 - Avogadro's Number, NA = 6.022 1023 1. [7...

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