Mole Mission TestMole Mission CP Chemistry Unit 4 Assessment Name: Date: Instructions: Show all work for calculation problems. Include proper units and significant figures for full credit. Periodic tables and calculators are permitted. PART I: CONCEPTUAL FOUNDATIONS 1. Which of the following is the correct value for Avogadro's number? 6.02 × 1022 6.02 × 1023 1.66 × 10-24 22.4 2. The molar mass of an element is numerically equal to its: Atomic number in grams per mole Average atomic mass in grams per mole Total number of valence electrons 3. How many total moles of atoms are in one mole of H2SO4? 3 4 6 7 PART II: MOLAR CONVERSIONS 4. Calculate the number of moles in 75.0 grams of Iron (Fe). 5. How many molecules are present in 2.50 moles of Water (H2O)? PART III: PERCENT COMPOSITION 6. Calculate the percent composition by mass of every element in Glucose (C6H12O6). PART IV: STOICHIOMETRY Use the following balanced chemical equation for questions 7 and 8: 2 H2 + O2 → 2 H2O 7. (Mole-to-Mole) If you start with 5.0 moles of Oxygen (O2), how many moles of Water (H2O) can be produced? 8. (Mass-to-Mass) How many grams of Hydrogen (H2) are required to react completely with 32.0 grams of Oxygen (O2)? Unit 4 Assessment End of Test
Mole Mission Answer KeyMole Mission TEACHER ANSWER KEY Grading Reference Part I: Conceptual 6.02 × 1023 (Correct scientific notation) Average atomic mass in grams per mole (Definition of molar mass) 7 moles (2 H + 1 S + 4 O = 7 atoms) Part II: Molar Conversions 4. 75.0g Fe to Moles 75.0 g Fe × (1 mol Fe / 55.85 g Fe) = 1.34 mol Fe 5. 2.50 moles H2O to Molecules 2.50 mol H2O × (6.02 × 1023 molecules / 1 mol) = 1.51 × 1024 molecules Part III: Percent Composition Glucose (C6H12O6) Molar Mass: 180.18 g/mol % C: (72.06 / 180.18) × 100 = 40.00% % H: (12.12 / 180.18) × 100 = 6.73% % O: (96.00 / 180.18) × 100 = 53.28% Part IV: Stoichiometry 7. 5.0 mol O2 to mol H2O 5.0 mol O2 × (2 mol H2O / 1 mol O2) = 10. mol H2O 8. 32.0g O2 to grams H2 STEP 1 32.0g O2 / 32.00 g/mol = 1.00 mol O2 STEP 2 1.00 mol O2 × (2 mol H2 / 1 mol O2) = 2.00 mol H2 STEP 3 2.00 mol H2 × 2.016 g/mol = 4.03 g H2
Mole Mission SlidesMole Mission Unit Review & Test Prep 6.022 × 1023 • n = m/M • Stoichiometry What is a Mole? A mole is the SI unit for amount of substance. 1 mol = 6.02 × 1023 particles Counting Units: 1 Dozen = 12 1 Ream = 500 1 Mole = 6.02 × 1023 The Conversion Roadmap Grams Molar Mass The Island MOLES Count 6.02 × 1023 Stop at The Island first to switch units! Percent Composition Tells you the percentage by mass of each element in a compound. Formula % = (Mass of Element / Total Mass) × 100 Step 1 Find molar mass of compound. Step 2 Divide element mass by total mass. Step 3 Multiply by 100. Stoichiometry Master Plan 01 Balance It You MUST have a balanced equation for the Mole Ratio. 02 To Moles Convert your starting grams to moles using Molar Mass. 03 Switch It Use the Mole-to-Mole ratio to jump from Sub A to Sub B. "Grams → Moles → Moles → Grams"
