University:
Concordia University Wisconsin
Course:
CHEM 1414 | General Chemistry I
Academic year:

2021
Views:

111

Pages:

2
Author:

Hallie Randolph

Chemistry More Moles, Please! 1. How many moles of Helium atoms are there in 6.46g of Helium? 2. How many grams of Zn are in 0.356 mol of Zn? 3. What is the molar mass of SO2 and C8H10N4? 4. How many moles of CH4 are in 6.07g of CH4? 5. How many hydrogen atoms are present in 25.6g of urea, (NH2)2CO? 6. How many moles of cobalt atoms are in 6.00 x 109 Co atoms? 7. How many grams of gold are there in 15.3 moles? 8. What is the mass in grams of a single atom of As? 9. The density of water at 4oC is 1.00g/mL. How many water molecules are present in 2.56mL of H2O at this temperature? STOP! Check your answers with your lab partners. Call the teacher over for help if your answers are not matching… Let’s try some more… 1. What is the Molar Mass of Propane C3H8? 2. What is the Molar Mass of Al2(SO4)3? 3. What is the Molar Mass of one mole of Oxygen gas (O2)? 4. What is the Mass of one molecule of oxygen gas? 5. What is the Mass of one mole of oxygen atoms? 6. What is the Mass of one atom of oxygen? Chemistry 7. If a steel cylinder contains 3.01 x 1023 carbon dioxide molecules, how many moles of oxygen atoms are in the cylinder? 8. How many carbon dioxide molecules are in 0.75 mol of CO2? 9. How many atoms are there in 26.0g of carbon? 10. How many moles of carbon are in 26 g of carbon? 11. How many oxygen atoms are in 0.75 mol CO2? Solutions to the second set of 11 questions: 1. (3x12.0) + (8x1.01) = 44.1g 2. (2x27.0) + (3x16.0) + (12x16.0) =342.3g 3. (2x16.0) = 32.0g 4. (1 mol/6.02 x 1023molecules)(32.0g/mol) = 5.32 x 10-23g 5. 16.0g 6. (1 mol/6.02 x 1023molecules)(16.0g/mol) = 2.66 x 10-23g 7. (3.01 x 1023 CO2 molec)(2 O atoms/1 CO2 molec)(1 mol O atoms/6.02 x 1023 O atoms) = 1.00 mol of O atoms 8. (0.75 mol)(6.02 x 1023 molecules/1 mol) = 4.5 x 1023 molecules of CO2 9. (26.0g)(1 mol/12.0g)(6.02 x 1023 atoms/1 mol) = 1.30 x 1024 atoms 10. (26g)(1 mol/12.0g) = 2.2 mol 11. (0.75mol CO2)(6.02x1023 molec CO2/mol CO2)(2 O atoms/CO2 molec) = 9.0x1023 O atoms Be sure to check your sig figs!