Problems on Percent Composition, Empirical Formula, and Molecular Formula

STOICHIOMETRY KEY

PROBLEMS ON PERCENT COMPOSITION, EMPIRICAL FORMULA, AND MOLECULAR FORMULA

1.  174.2 amu, 64 amu, 74 amu

2.  101.1 g/mole, 120.3 g/mole, 108 g/mole

3.  47.88 grams sodium sulfite

4.  .48 moles lithium carbonate

5.  6.74 x 1025 atoms Li

6.  1.52 x 1024 molecules ammonia

7.  5.26 x 1023 formula units magnesium sulfate

8.  6.59 x 1022 ions of sulfate

9.  49.28 liters methane

10. Na = 32.4%

11. Cr = 42.3%

12. 38.3% chlorine, 61.7% fluorine

13. 35% nitrogen, 5% hydrogen, 60% oxygen

14. Ammonia – contains 82.4% nitrogen, whereas ammonium nitrate contains 35% N

15. 20.2% phosphorous

16. 46.1% sulfur

17. Zn1Cl2, Sn1I4, Pb1(NO3)2, K2S1O4

18. Al2O3, Na2S1

19. C2H6, C2H2, C4H8Cl2

20. C5H7N1 = EF, C10H14N2 = MF

21. C10H10N4O2S1

22. C3H6O1

23. C5H7N1 = EF, C10H14N2 = MF

24. C18H27NO3

25. C14H18N2O5

26. C3H6O3

27. C2F3H1Br1Cl1

28. C4H4O1

29. C8H8O3

30. C1H3O1; 38.71% carbon, 9.68% hydrogen, 51.61% oxygen

31. N1O2; N2O4

32. C3H7O3; C6H14O6

33. C8H11N1O3

34. Ca5P3O13H1; Ca10P6O26H2

35. C7H15Cl2N2O2P1

36. C57H110O6 – both EF and MF

37. C4H7O1; yes – it has a mass that is a multiple of 213.29 g/mole

38. C1H2O1; C3H6O3

39. C10H18O1

EASY STOICHIOMETRY PROBLEMS

1.  3.05 moles CO2

2.  .625 moles W2C3

3.  6.75 moles carbon dioxide

4.  .32 moles Al2O3

5.  2.30 moles CH3OH

6.  .90 moles AgNO3

7.  3.80 moles NaClO3

8.  18.72 moles O2

9.  .256 moles H2

10. .31 moles O2

11. .5 moles H2

12. .35 moles H3PO4

13. 336 grams NaOH

14. 108 grams Al

15. 1.125 moles ZnCl2

16. 180.9 grams Al

17. 56.0 liters SO2

18. 2.47 x 1024 molecules O2

19. 255 L H2

20. 35.5 liters Cl2 gas

21. 87.03 grams PbS

22. 397.5 grams Ag

23. 24.6 grams HCl

24. 63.23 liters CO2, 50.81 grams H2O

25. 178.3 liters N2, 122.1 grams Na

26. 22.4 liters CO2, HCl is limiting reactant

27. 58 grams BaSO4, Ba(NO3)2 is limiting reactant

28. 33.8 liters CO2, O2 is limiting reactant

29. 295 grams SrCO3, SrCl2 is limiting reactant

30. 9.7 L O2 theoretical, 67% yield

31. 25.2 liters H2, HCl is limiting reactant

TOUGHER PROBLEMS WITH STOICHIOMETRY!

1.  O2 runs out, 28.1 grams water produced, H2 excess

2.  22.3 grams of BaSO4

3.  24.8 grams H2O

4.  718 grams Ni(ClO3)2

5.  16.94 grams H2O

6.  25.14 L SO2

7.  91.19 grams CaO

8.  66.8 liters NH3

9.  4 moles HF, 5.25 grams NaF, 8.01 grams Na2SiO3

10. 127 grams AlPO4

11. 402 grams of Ba

12. 248 grams of Na2O

13. 24.1 grams H2O

14. 66 grams of Fe3(PO4)2

15. 5.375 x 1024 molecules

16. 702 grams Al(ClO3)3

17. 82.2 grams AgI

18. potassium is the limiting reactant; 149 g of KCl are produced

19. 150. Grams of F2O7

20. 34.0 L of O2

21. Cl2O5 is the limiting reactant; 185 grams of Ca(ClO3)2 produced

22. 99.4 grams P2O5

23. 297 grams LiClO4, and 25.0 grams H2O

24. 19.8 grams H2O, 400.4 grams NaIO2

25. 3.62 grams I2O7

ULTIMATE STOICHIOMETRY PROBLEMS WITH NON-STANDARD GASES

1.  20.0 liters NH3

2.  .046 grams LiClO3

3.  111 psi CO2

4.  2640 mL H2

5.  33.3L O2

6.  14.4 L NH3

7.  .133 g Al2(CO3)3

8. 

a.  Na2SO3

b.  .794 moles SO2 created

c.  18.9 L SO2

9.  .069 grams Zn

10. 23.2 L Cl2

11. 2.50 L O2

12. 31.5 L CO2

13. 22.9 g NH4Br, 20.0 g Ba(OH)2

14. 350 g H3AsO4

15. 65.8 grams HClO3

16. 5.70 L SO3 gas

17. 15.3 L SO2 gas

18. 2340 g Sn(OH)4