Name____________________________
Date_____________________Pd______
Review for Week 4 Test
Find the molar mass of the following compounds:
1. FeO
2. K2S
3. (NH4)2CO3
4. Cr2(SO4)3
Find the percent composition for each of the elements in the following compounds:
4. FeO
5. K2S
6. (NH4)2CO3
7. Cr2(SO4)3
Calculate the molecular formula using the given information:
8. A compound with empirical formula C2OH4 and a molar mass of 264.318 grams per mole.
9. A compound with empirical formula C4H4O and a molar mass of 136.15 grams per mole.
Calculating Empirical and Molecular Formulas
10. A component of protein called serine has an approximate molar mass of 100 g/mole. If the
percent composition is as follows, what is the empirical and molecular formula of serine?
C = 34.95 % H= 6.844 % O = 46.56 % N= 13.59 %
11. 200.00 grams of an organic compound is known to contain 83.999 grams of carbon, 10.570
grams of hydrogen, 18.640 grams of oxygen and the rest is nitrogen. The molecular mass of the
compound is 515.523 grams per mole. What are the empirical and molecular formulas of the
compound?
12. 300 grams of an organic sample which contains only carbon, hydrogen and oxygen is
analyzed and found to contain 145.923 grams of carbon, 24.492 grams of hydrogen and the rest
is oxygen. The molecular mass of the compound is 222.237 grams per mole. What are the
empirical and molecular formulas of the compound?
Molar Conversions (must use dimensional analysis, show your work!)
13. How many moles are there in 54 grams of Ba(OH)2 ?
14. How many formula units are there in 3.4 moles of CO2 ?
15. How many grams are there in 7.08 x 1024 formula units of K2O ?
16. How many molecules are there in 121.3 grams of N2O4 ?
Name____________________________
Date_____________________Pd______
Review for Week 4 Test
Find the molar mass of the following compounds:
3. FeO
4. K2S
3. (NH4)2CO3
4. Cr2(SO4)3
Find the percent composition for each of the elements in the following compounds:
6. FeO
7. K2S
6. (NH4)2CO3
7. Cr2(SO4)3
Calculate the molecular formula using the given information:
8. A compound with empirical formula C2OH4 and a molar mass of 264.318 grams per mole.
9. A compound with empirical formula C4H4O and a molar mass of 136.15 grams per mole.
Calculating Empirical and Molecular Formulas
10. A component of protein called serine has an approximate molar mass of 100 g/mole. If the
percent composition is as follows, what is the empirical and molecular formula of serine?
C = 34.95 % H= 6.844 % O = 46.56 % N= 13.59 %
11. 200.00 grams of an organic compound is known to contain 83.999 grams of carbon, 10.570
grams of hydrogen, 18.640 grams of oxygen and the rest is nitrogen. The molecular mass of the
compound is 515.523 grams per mole. What are the empirical and molecular formulas of the
compound?
12. 300 grams of an organic sample which contains only carbon, hydrogen and oxygen is
analyzed and found to contain 145.923 grams of carbon, 24.492 grams of hydrogen and the rest
is oxygen. The molecular mass of the compound is 222.237 grams per mole. What are the
empirical and molecular formulas of the compound?
Molar Conversions (must use dimensional analysis, show your work!)
13. How many moles are there in 54 grams of Ba(OH)2 ?
14. How many formula units are there in 3.4 moles of CO2 ?
15. How many grams are there in 7.08 x 1024 formula units of K2O ?
16. How many molecules are there in 121.3 grams of N2O4 ?