Writing Formulas
1.
sodium nitrate 16. aluminum sulfide

2. iron (III) sulfate 17. strontium hydroxide

3. copper (I) phosphate 18. cesium carbonate

4. nickel (II) oxide 19. silicon dioxide

5. potassium bromide 20. zinc chlorate

6. barium acetate 21. iron (II) phosphide

7. magnesium chromate 22. calcium nitride

8. silver sulfite 23. sodium bicarbonate

9. copper (II) chloride 24. ammonium dichromate

10. dinitrogen tetroxide 25. potassium iodide

11. rubidium sulfate 26. lead (II) acetate

12. beryllium nitrate 27. ammonium sulfide

13. phosphorus trichloride 28. silver carbonate

14. magnesium fluoride 29. ammonium phosphate

15. lead (II) bromide 30. nickel (II) iodide

 

 

Naming Compounds
1. NaCl 14. Ba3(PO4)2  

2. Al2O3    15. Ni(ClO)2

3. CuSO4    16. ZnCr2O7

4. MgCl2    17. LiOH

5. (NH4)3PO4    18. AgHCO3

6. Pb(NO3)2    19. Fe(C2H3O2)3

7. K2CO3   20. CO2

8. NO2    21. Cu2CrO4

9. SrSO3    22. Al(OH)3

10. RbNO2    23. N2O

11. FeBr2    24. AgClO2

12. P2O5    25. CaI2

13. Cu(ClO3)2    26. SO2

 

1.)

HCl


Cl:

 

11.)

H2SO3

 

S:

 

2.)

KNO3

 

N:

 

12.)

H2SO4

 

S:

 

3.)

Fe(OH)3

 

Fe:

 

*13.)

BaO2

 

O:

 

4.)

Mg3N2

N:

 

14.)

KMnO4

 

Mn:

 

5.)

KClO3

Cl:

 

*15.)

LiH

 

H:

 

6.)

Al(NO3)3

 

N:

 

16.)

MnO2

 

Mn:

 

7.)

S8

 

S:

 

17.)

OF2

 

O:

 

8.)

Li2CO3

 

C:

 

18.)

SO3

 

S:

 

9.)

PbO2

 

Pb:

 

19.)

NH3

 

N:

 

10.)

NaHSO4

 

S:

 

20.)

Na

 

Na:

 

 

 


Percent Composition

Determine the percent composition of each of the following compounds.

1.  KMnO4 K = Mn = O =

 

2.  HCl H = Cl =

 

3.  Mg(NO3)2 Mg = N = O =

 

4.  (NH4)3PO4 N = H = P = O =

 

5.  Al2(SO4)3 Al = S = O =

 

Solve the following problems.

6.  How many grams of oxygen can be produced from the decomposition of 100. g of KClO3?

7.  How much iron can be recovered from 25.0 g of Fe2O3?

8.  How much silver can be recovered from 125 g of Ag2S?

 

 

Empirical Formulas

Find the empirical formula for each of the following substances. The percent composition is given.

1.  88.8 % copper & 11.2 % oxygen

2.  10.04 % carbon, 0.84 % hydrogen, & 89.12 % chlorine

3.  42.50 % chromium & 57.50 % chlorine

4.  38.67 % potassium, 13.85 % nitrogen, & 47.48 % oxygen

5.  72.40 % iron & 27.60 % oxygen

Part 2 Determine the empirical formula of the following compounds using the given data.  

6. Find the empirical formula for sodium sulfite. Sodium sulfite contains 36.5 % sodium,
     25.4 % sulfur, and 38.1 % oxygen.

7. What is the empirical formula for a compound which contains 53.73 % iron and 46.27 %
     sulfur?

8. What is the empirical formula of a compound if the percentage composition is:
aluminum 15.77 %, sulfur 28.11 %, and oxygen 56.12 %?

9.  If 8.87 grams of phosphorus react with 11.43 grams of oxygen, what is the empirical
     formula of the compound formed?

10. Phosgene, a poisonous gas used during World War I, contains 12.1 % C, 16.2 % O, and
       71.7% Cl. What is the empirical formula for phosgene?

 

Molecular Formulas 
Solve the following problems.

1.  A compound is found to be 40.0 % carbon, 6.7 % hydrogen, and 53.5 % oxygen. Its
    molecular mass is 60. grams per mole. What is its molecular formula?

2.  A compound is 64.9 % carbon, 13.5 % hydrogen, and 21.6 % oxygen. Its molecular
     mass is 74 grams per mole. What is its molecular formula?

3.  A compound is 54.5 % carbon, 9.1 % hydrogen, and 36.4 % oxygen. Its molecular mass
     is 88 grams per mole. What is its molecular formula?

4.  If the molecular mass of an oxide of nitrogen is 108. What is the molecular formula of a
     compound that contains 4.02 grams of nitrogen and 11.48 grams of oxygen?

5. An organic compound is found to contain 92.25 % carbon and 7.75 % hydrogen. If the
     molecular mass is 78, what is the molecular formula?

6. The formula mass of a compound is 92. Analysis of the compound shows that there are
     0.608 grams of nitrogen and 1.388 grams of oxygen. What is the molecular formula of
     this compound?

7. There are two different oxides of phosphorus. Both oxides can exist in different forms
     depending on the temperature and pressure. Calculate the empirical and molecular
     formulas from the following data:
(A) P: 56.4 %, O: 43.7 %, molecular mass = 220
(B) P: 43.6 %, O: 56.4 %, molecular mass = 284

8. Nicotine is a compound that contains 74.0 % carbon, 8.7 % hydrogen, and 17.3 %
     nitrogen. If the molecular mass is 162, what is the molecular formula?

 

Composition of Hydrates

1.  A hydrated sodium salt containing 39.7 % water is analyzed as follows: Na 16.9 %, C
    17.7 %, H 6.67 %, and O 58.8 %. What is the empirical formula of this salt?

2. Nicotine is a compound that contains 74.0 % carbon, 8.7 % hydrogen, and 17.3 %
     nitrogen. If the molecular mass is 162, what is the molecular formula?

3.  Strontium hydroxide is isolated as a hydrate, which means that a certain number of water
     molecules are included in the solid. When 6.85 grams of the hydrate are dried in an oven,
     3.13 grams of anhydrous Sr(OH)2 are formed.

4.  A 2.5 gram sample of a hydrate of Ca(NO3)2 was heated, and only 1.7 grams of the
     anhydrous salt remained. What percentage of water was in the hydrate?

5.  A 5.0 gram sample of Cu(NO3) 2 . n H2O is heated, and 3.9 gram sample of the
     anhydrous salt remains. What is the value of n?

 

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