Mole Island First Problems Answer Key

University:
Felician University
Course:
CHEM-105 | Principles of Chemistry
Academic year:

2024
Views:

392

Pages:

2
Author:

Clint W.

Chemistry Mole Island WS Name: Date: Per: Define: mole: 1 mole = 6.02 x 10^23 particles (or atoms or molecules or formula units) molar mass: g/mol (periodic table or mol) particles: atoms or molecules or formula units (NaCl) molar volume: 22.4 L/mol or 1 mol/22.4 L Solve: 1. Determine the mass of 1 mole of the following substances. a. Ca 40.078 g/mol Ca b. H₂S 1.01(2) + 32.1 = 34.1 g/mol H₂S c. O₂ 15.9 x 2 = 32.0 g/mol O₂ 2. Determine the number of moles present in each of the following masses. a. 5.6 g Na 5.6 g Na x 1 mol Na / 22.99 g Na = 0.24 mol Na b. 15.78 g CO₂ c. 1.4 x 10^4 g N₂ 3. Calculate the mass of each of the following number of moles. a. 2.0 moles of C 2.0 mol C x 12.01 g C / 1 mol C = 24.0 g C b. 0.75 moles of H₂O c. 1.57 moles of NaCl 4. How many particles are present in each of the following substances? a. 2.5 moles of Fe 2.5 mol Fe x 6.02 x 10^23 atoms Fe / 1 mol Fe = 1.5 x 10^24 atoms Fe b. 0.781 moles of CuSO₄ c. 120 moles of F₂ 5. Determine the number of moles present in each of the following: a. 5.0 x 10^23 atoms of Ni 5.0 x 10^23 atoms Ni x 1 mol Ni / 6.02 x 10^23 atoms = 0.83 mol Ni b. 1.68 x 10^24 molecules of Cl₂ 1.68 x 10^24 molecules Cl₂ x 1 mol Cl₂ / 6.02 x 10^23 molecules = 2.8 mol Cl₂ c. 3.2 x 10^23 particles of CaCl₂ 6. What volume of gas is present at STP? a. 5.0 moles of H₂ 5.0 mol H₂ x 22.4 L H₂ / 1 mol H₂ = 112 L H₂ b. 20.0 moles of H₂O(g) c. 1.5 x 10^25 moles of CO₂ 7. Determine the number of moles present in each of the following volumes of gases at STP. a. 25 L F₂ 25 L F₂ x 1 mol F₂ / 22.4 L F₂ = 1.11 mol F₂ b. 20.5 L Xe c. 50 L Ne 8. Calculate the number of particles in each of the following @ STP. a. 25 g of Li 25 g Li x 1 mol Li / 6.94 g Li x 6.02 x 10^23 atoms Li / 1 mol Li = 2.2 x 10^24 atoms Li b. 0.725 g of Br₂ c. 28 L of NO(g) 9. What is the mass of each of the following substances? a. 5.6 x 10^23 particles of Pb 5.6 x 10^23 particles Pb x 1 mol Pb / 6.02 x 10^23 particles x 207.2 g Pb / 1 mol Pb = 194 g Pb b. 1.02 x 10^25 particles of NO₂ c. 25 L of CO₂ @ STP 10. Determine the volume of gas for each of the following @ STP. a. 7.3 x 10^20 particles of Cl₂ 7.3 x 10^20 particles Cl₂ x 1 mol Cl₂ / 6.02 x 10^23 particles x 22.4 L Cl₂ / 1 mol Cl₂ = 0.027 L Cl₂ b. 5.0 g of H₂ c. 1.8 x 10^24 particles of Ne