CHEM 103 MODULE 1 TO 6 EXAM ANSWERS PORTAGE LEARNING GRADED A+

CHEM 103 MODULE 1 TO 6 EXAM ANSWERS PORTAGE LEARNING GRADED A+ Question 1 Click this link to access the Periodic Table. This may be helpful throughout the exam. 1. Convert 845.3 to exponential form and explain your answer. 2. Convert 3.21 x 10-5 to ordinary form and explain your answer. 1. Convert 845.3 = larger than 1 = positive exponent, move decimal 2 places = 8.453 x 102 2. Convert 3.21 x 10-5 = negative exponent = smaller than 1, move decimal 5 places = 0. Question 2 Using the following information, do the conversions shown below, showing all work: 1 ft = 12 inches 1 pound = 16 oz 1 gallon = 4 quarts 1 mile = 5280 feet 1 ton = 2000 pounds 1 quart = 2 pints kilo (= 1000) 1/100) milli (= 1/1000) deci (= 1/10) centi (= 1. 24.6 grams = ? kg 2. 6.3 ft = ? inches 1. 24.6 grams x 1 kg / 1000 g = 0.0246 kg 2. 6.3 ft x 12 in / 1 ft = 75.6 inches please always use the correct units in your final answer Question 3 Do the conversions shown below, showing all work: 1. 28oC = ? oK 2. 158oF = ? oC 3. 343oK = ? oF 1. 28oC + 273 = 301 oK oC → oK (make larger) +273 2. 158oF - 32 ÷ 1.8 = 70 oC oF → oC (make smaller) -32 ÷1.8 3. 343oK - 273 = 70 oC x 1.8 + 32 = 158 oF oK → oC → oF Question 4 Be sure to show the correct number of significant figures in each calculation. 1. Show the calculation of the mass of a 18.6 ml sample of freon with density of 1.49 g/ml 2. Show the calculation of the density of crude oil if 26.3 g occupies 30.5 ml. 1. M = D x V = 1.49 x 18.6 = 27.7 g 2. D = M / V = 26.3 / 30.5 = 0.862 g/ml Question 5 1. 3.0600 contains ? significant figures. 2. 0.0151 contains ? significant figures. 3. 3.0600 ÷ 0.0151 = ? (give answer to correct number of significant figures) 1. 3.0600 contains 5 significant figures. 2. 0.0151 contains 3 significant figures. 3. 3.0600 ÷ 0.0151 = 202.649 = 203 (to 3 significant figures for 0.0151) Question 6 Classify each of the following as an element, compound, solution or heterogeneous mixture and explain your answer. 1. Coca cola 2. Calcium 3. Chili 1. Coca cola - is not on periodic table (not element) - no element names (not compound) appears to be one substance = Solution 2. Calcium - is on periodic table = Element 3. Chili - is not on periodic table (not element) - no element names (not compound) appears as more than one substance (meat, beans, sauce) = Hetero Mix Question 7 Classify each of the following as a chemical change or a physical change 1. Charcoal burns 2. Mixing cake batter with water 3. Baking the batter to a cake 1. Charcoal burns - burning always = chemical change 2. Mixing cake batter with water - mixing = physical change 3. Baking the batter to a cake - baking converts batter to new material = chemical change Click this link to access the Periodic Table. This may be helpful throughout the exam. Show the full Nuclear symbol including any + or - charge (n), the atomic number (y), the mass number (x) and the correct element symbol (Z) for each element for which the protons, neutrons and electrons are shown - symbol should appear as follows: xZy+/- n 31 protons, 39 neutrons, 28 electrons 31 protons = Ga31, 39 neutrons = 70Ga31, 28 electrons = (+31 - 28 = +3) = 70Ga +3 Question 9 Name each of the following chemical compounds. Be sure to name all acids as acids (NOT for instance as binary compounds) 1. PF5 2. Al2(CO3)3 3. H2CrO4 1. PF5 - binary molecular = phosphorus pentafluoride 2. Al2(CO3)3 - nonbinary ionic = aluminum carbonate 3. H2CrO4 - nonbinary acid = chromic acid incorrect fluoride prefix Question 10 Write the formula for each of the following chemical compounds explaining the answer with appropriate charges and/or prefixes and/or suffixes. 1. Carbon monoxide 2. Manganese (IV) acetate 3. Phosphorous acid 1. Carbon monoxide - ide = binary, mono = 1 O = CO 2. Manganese (IV) acetate - Mn+4, C2H3O -1 = Mn(C2H3O2)4 3. Phosphorous acid - nonbinary acid of H + phosphite (PO -3) = H PO