Name __________________________ Period ____________ Accelerated Chemistry The Mole Review Format of the Exam: • The entire exam will be multiple choice. • There are 14 multiple choice questions. o Each multiple choice question will have a follow up “A” question to explain your reasoning in your answer. o Therefore making the entire test 28 questions all multiple choice. Important Unit Topics: • Significant Figures • Scientific Notation • Dimensional analysis o Years ! Days ! Hours ! Minutes ! Seconds o Molecules (or atoms) ! moles ! Grams • The mole o What is it? Why is it used? What does it mean to have a mole of something • Atomic Mass • Molecular/Formula Mass • Molar Mass • Percent composition • Empirical Formula o What is it? o How to calculate it What you will be given on the test: • Periodic Table • Scratch paper What you will NOT be given on the test: • Electronegativity values (you won’t need them) • Polyatomic Ion cheat sheet (you will need to have them all memorized) • Mole road (you will have to understand how to do this on your own) Practice Problems 1. ______What is the molar mass of Nickel (III) Acetate? a. 235.825 amu b. 235.853 g/mol c. 117.737 g/mol d. 117.737 amu A. _______Choose the answer that best explains your reasoning a. Molar mass is found on the periodic table and is measured in g/mol b. To find molar mass you add up the mass of each element in the compound measured in g/mol c. To find molar mass you add up the mass of each element in the compound measured in amu d. Molar mass is found on the periodic table and is measured in amu 2. How many significant figures are there in the following numbers A.) 0.00040 __________________________ B.) 1.500 x 10 5 ________________________ C.) 100,000.0 _________________________ D.) 5050 _____________________________ 3. Convert the following to scientific notation or to standard notation and write your answer with the same amount of significant figures Standard Notation Scientific Notation 0.00300 ____________ ____________ 2.5 x 10 -4 10.00 ____________ ____________ 1.9 x 10 7 0.070 ____________ 4. Solve the following problems. Make sure to show all your work and have your answer in the correct significant figures with units. a. Ms. Dillemuth’s birthday is today and she is exactly 25 years old. Tell her how many seconds old she is. b. You are on a mission to be part of the gallon water club. Meaning that you drink a gallon of water per day. How many cubic cm is this (cm3)? Volume 1 qt. = 0.946 L 4 qt. = 1 gal 1000 ml = 1 L 1000 cm3 = 1 L 1 m3 = 1000 L 5. Explain the difference between a mole of feathers and a mole of paper. In your explanation discuss the amounts of the substance relative to the mass. 6. Relate how a mole of Sodium acetate is similar and different to a mole of Lithium oxide. 7. Explain the difference between molecular mass and formula mass. 8. Explain the difference between 44.01 g/mol and 44.01 amu. 9. Calculate the molar mass of the following compounds: Name Formula Ammonium Sulfide Potassium Nitrate Silver (I) Acetate Calcium Hydroxide 10. Calculate the percent of carbon in the following compounds a. CH4 b. C2H3O2 Molar mass 11. Determine the empirical formula for problem below. a. A compound contains 0.0130 mol carbon, 0.0390 mol hydrogen, and 0.0065 mol oxygen. b. A compound consists of 72.2% magnesium and 27.8% nitrogen by mass. 12. What are the empirical and molecular formulas for a compound with 83.625% carbon and 16.375% hydrogen and a molecular weight of 388.78? 13. A compound is found to contain 50.05 % sulfur and 49.95 % oxygen by weight. What is the empirical formula for this compound? The molecular weight for this compound is 64.07 g/mol. What is its molecular formula?
© Copyright 2024