Chem%20161-2009%20Exam%20I%20%2B%20detailed%20solutions

Chem%20161-2009%20Exam%20I%20%2B%20detailed%20solutions -...

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1 Chemistry 161 Exam I September 30, 2009 Student Name: Edward Tavss Recitation Instructor: Edward Tavss Your EXAM FORM is 1 Chem 161-2009 Exam I Hill, Petrucci et al. Chapter 2 – Atoms, Molecules and Ions Nomenclature (naming) 1. Which of the following compounds is incorrectly named? A. HIO 4 ; periodic acid B. BaSO 3 ; barium sulfite C . TiBr 4 ; titanium(IV) tetrabromide D. NaNO 3 •6H 2 O; sodium nitrate hexahydrate E. Br 2 O 5 ; dibromine pentoxide A. Correct. B. Correct. C. Incorrect. It is named according to type II (transition metals) nomenclature, which would be titanium(IV) bromide. D. Correct. E. Correct. Chem 161-2009 Exam I Hill, Petrucci et al. Chapter 2 – Atoms, Molecules and Ions Nature of the atom (protons, neutrons, electrons, symbols, etc.) including isotopes 2. How many protons, neutrons and electrons are in the 85 Rb atom? A. 48 protons, 48 neutrons and 37 electrons B. 37 protons, 37 neutrons and 48 electrons C. 48 protons, 37 neutrons and 48 electrons D . 37 protons, 48 neutrons and 37 electrons E. 37 protons, 48 neutrons and 48 electrons The atomic number is 37; therefore, it has 37 protons. Since the atom is uncharged, it also has 37 electrons. Since the mass number is the sum of the protons and neutrons, then the number of neutrons is (85-37=) 48. Therefore, this atom has 37 protons, 48 neutrons and 37 electrons. Chem 161-2009 Exam I Hill, Petrucci et al. Chapter I – Chemistry: Matter and Measurement Classification of matter 3. Select chemical change(s) from the following. I. Liquid chlorine turns to gas at room temperature. II. Fruit rotting III. Distillation of octane from crude oil IV. Metal sodium forming hydrogen gas when in contact with water A. I, II and IV
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2 B. I, II, and III C. I and III D . II and IV E. III and IV A chemical change is one in which the atomic or molecular structure of the atom or molecule changes. I. No. When chlorine goes from a liquid to a gas it remains as chlorine; i.e., the structure doesn’t change. This is a physical change. II. Yes. When fruit rots microorganisms are reacting with certain molecules to convert them into new molecules. This is a chemical change. III. No. Distillation just separates the octane from the rest of the oil. It doesn’t change the chemical structure of any of the components. IV. Yes. When sodium metal reacts with water, it forms sodium ion from the sodium atom, and hydrogen gas from water. These are chemical changes. Chem 161-2009 Exam I Hill, Petrucci et al. Chapter I – Chemistry: Matter and Measurement Units/unit conversions/dimensional analysis 4. What is the mass (in kg) of a block of magnesium (Density: 1.738 g/cm 3 ) with a volume of 24.3 mm 3 ? A . 4.22 x 10 -5 kg B. 4.22 x 10 -2 kg C. 4.22 x 10 -4 kg D. 4.22 x 10 1 kg E. 4.22 x 10 3 kg 24.3 mm 3 kg 1 cm = 0.01m 1 mm = 0.001 m 24.3 mm 3 kg Plan: Convert the conversion units to correspond to kg/mm 3 . 1.738 g/cm
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This note was uploaded on 03/08/2011 for the course CHEM 161 taught by Professor Vacillian during the Fall '08 term at Rutgers.

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Chem%20161-2009%20Exam%20I%20%2B%20detailed%20solutions -...

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