Analía Bellizzi – Chemistry Classes

Ronald Reagan High School

The Mole Exercises #2

MOLE EXERCISES #2 – (answers between parenthesis)

Show your work to obtain credit – no units, no points!!!

    1. Calculate the mass of 3.0 x 1012 (3 trillion) nickel atoms. = 2.94×10-10g
    2. Calculate the mass of 1 tungsten (W) atom. = 3.05×10-22g
    3. Calculate the number of atoms in 0.57 g of nickel = 5.81×1021 at
    4. Calculate the number of atoms in 1×10-12 g (1 picogram) of tungsten (W). = 3.27×109 at
    5. Calculate the mass of 0.357 mole of gold. =70.33 g
    6. Calculate the number of moles in 10.0 g of silicon. = 0.357 mol
    7. Calculate the molar mass of gallium, Ga = 70.00 g
    8. Calculate the molar mass of benzoyl peroxide, C14H10O4 =242 g/mol
    9. Calculate the molar mass of Ca3(PO4)2 =310.g
    10. Convert 35.00 g of CF2Cl2 to moles. = 0.289 mole
    11. Convert 13.00 g of caffeine, C4H5N2O to moles. Ans. 0.134 mole
    12. Convert 12.5 g of SnF2 to number of molecules. Ans. 4.79 x 1022 molecules
    13. Convert 6.0 g of urea, CH4N2O, to number of molecules. = 6.02 x 1022 molecules
    14. Calculate the mass of 17.5 mole of N2. = 490. g
    15. Calculate the mass of 20.0 mole of NH3. = 340. g
    16. Calculate the mass of one sucrose molecule, C12H22O11 (M342. g). = 5.68 x 10-22g
    17. Calculate the number of oxygen atoms in 0.1364 g of citric acid, C6H8O7 (molar mass 192. g). Ans=2.99 x 1021 oxygen atoms
    18. Calculate the number of N atoms in 127.2 g of TNT, C7H5(NO2)3 (molar mass 227. g). Ans. 1.01 x 1024 N atoms
    19. Calculate the number of hydrogen atoms in 0.10 g of citric acid, C6H8O7 (molar mass 192. g). Ans=2.51 x 1021 hydrogen atoms
    20. Calculate the total number of atoms in 9.6 g of citric acid, C6H8O7 (molar mass 192. g). Ans=6.32 x 1023  atoms