University:
High School
Course:
High School Chemistry
Academic year:

2021
Views:

398

Pages:

18
Author:

Erbavoria2

GRAM FORMULA MASS Determine the gram formula mass (the mass of one mole) of each compound below. KMnO₄ 158g KCl 74.55g Na₂SO₄ 142g Co(NO₃)₂ 148g Al₂(SO₄)₃ 342g (NH₄)₃PO₄ 149g CuSO₄ ∙ 5H₂O 250g Mg₃(PO₄)₂ 262.86g Zn(C₂H₃O₂)₂ ∙ 2H₂O 219g Zn₃(PO₄)₂ ∙ 4H₂O 458g H₂CO₃ 62g Hg₂Cr₂O₇ 617g Ba(ClO₃)₂ 304g Fe₂(SO₃)₃ 352g NH₄C₂H₃O₂ 77g MOLES AND MASS Determine the number of moles in each of the quantities below. 25 g of NaCl 0.43 125 g of H₂SO₄ 1.28 g of KMnO₄ 0.633 74 g of KCl 0.99 35 g of CuSO₄ ∙ 5H₂O 0.14 Determine the number of grams in each of the quantities below. 2.5 moles of NaCl 146 0.50 moles of H₂SO₄ 49 1.70 moles of KMnO₄ 269 0.25 moles of KCl 19 3.2 moles of CuSO₄ ∙ 5H₂O 799 STOICHIOMETRY: MASS-MASS PROBLEMS 2KClO₃ → 2KCl + 3O₂ How many grams of potassium chloride are produced if 25 g of potassium chlorate decompose? KCl = 39 + 35.5 = 74.5 g/mol KClO₃ = 39 + 35.5 + 48 = 122.5 g/mol 25 g KClO₃ × (1 mol KClO₃ / 122.5 g KClO₃) × (2 mol KCl / 2 mol KClO₃) × (74.5 g KCl / 1 mol KCl) = 15.2 g KCl N₂ + 3H₂ → 2NH₃ How many grams of hydrogen are necessary to react completely with 50.0 g of nitrogen in the above reaction? 50.0 g N₂ × (1 mol N₂ / 28.02 g N₂) × (3 mol H₂ / 1 mol N₂) × (2.02 g H₂ / 1 mol H₂) = 10.7 g H₂ How many grams of ammonia are produced in the reaction in Problem 2? 50.0 g N₂ × (1 mol N₂ / 28.02 g N₂) × (2 mol NH₃ / 1 mol N₂) × (17.03 g NH₃ / 1 mol NH₃) = 60.7 g NH₃ 2AgNO₃ + BaCl₂ → 2AgCl + Ba(NO₃)₂ AgNO₃ = 108 + 14 + (3 × 16) = 170 g/mol AgCl = 108 + 35.5 = 143.5 g/mol How many grams of silver chloride are produced from 5.0 g of silver nitrate reacting with an excess of barium chloride? 5.0 1 g AgNO₃ × (1 mol AgNO₃ / 170 g AgNO₃) × (2 mol AgCl / 2 mol AgNO₃) × (143.5 g AgCl / 1 mol AgCl) = 4.2 g AgCl How much barium chloride is necessary to react with the silver nitrate in Problem 4? 5.0 g AgNO₃ × (1 mol AgNO₃ / 170 g AgNO₃) × (1 mol BaCl₂ / 2 mol AgNO₃) × (208.3 g BaCl₂ / 1 mol BaCl₂) = 3.1 g BaCl₂ STOICHIOMETRY: MIXED PROBLEMS N₂ + 3H₂ → 2NH₃ What volume of NH₃ at STP is produced if 25.0 g of N₂ is reacted with an excess of H₂? 25.0 g N₂ × (1 mol N₂ / 28.02 g N₂) × (2 mol NH₃ / 1 mol N₂) × (22.4 L NH₃ / 1 mol NH₃) = 40.0 L NH₃ 2KClO₃ → 2KCl + 3O₂ If 5.0 g of KClO₃ is decomposed, what volume of O₂ is produced at STP? 5.0 g KClO₃ × (1 mol KClO₃ / 122.55 g KClO₃) × (3 mol O₂ / 2 mol KClO₃) × (22.4 L O₂ / 1 mol O₂) = 1.37 L O₂ How many grams of KCl are produced in Problem 2? 5.0 g KClO₃ × (1 mol KClO₃ / 122.55 g KClO₃) × (2 mol KCl / 2 mol KClO₃) × (74.55 g KCl / 1 mol KCl) = 3.04 g KCl Zn + 2HCl → ZnCl₂ + H₂ What volume of hydrogen at STP is produced when 2.5 g of zinc react with an excess of hydrochloric acid? 2.5 g Zn × (1 mol Zn / 65.38 g Zn) × (1 mol H₂ / 1 mol Zn) × (22.4 L H₂ / 1 mol H₂) = 0.86 L H₂ H₂SO₄ + 2NaOH → H₂O + Na₂SO₄ How many molecules of water are produced if 2.0 g of sodium sulfate are produced in the above reaction? 2.0 g Na₂SO₄ × (1 mol Na₂SO₄ / 142.04 g Na₂SO₄) × (1 mol H₂O / 1 mol Na₂SO₄) × (6.022 × 10²³ molecules H₂O / 1 mol H₂O) = 8.5 × 10²¹ molecules H₂O 2AlCl₃ → 2Al + 3Cl₂ If 10.0 g of aluminum chloride are decomposed, how many molecules of Cl₂ are produced? 10.0 g AlCl₃ × (1 mol AlCl₃ / 133.34 g AlCl₃) × (3 mol Cl₂ / 2 mol AlCl₃) × (6.022 × 10²³ molecules Cl₂ / 1 mol Cl₂) = 6.76 × 10²² molecules Cl₂