Chemistry: Empirical & Molecular Formulas Name______

1) What is the empirical formula for C15H30O5H5?

2) A compound has an empirical formula of C2H4O3N. Its molar mass is 359 g. What is the molecular formula?

3) A compound contains 12.7 g iron & 7.29 g oxygen. Its molar mass is 87.85 g. What is its empirical formula? What is its molecular formula?

4) A compound contains 65.6% carbon, 9.45% hydrogen & 25.0% oxygen. Its molar mass is 1922.85 g. What is its empirical formula? What is its molecular formula?

5) A compound contains 92.2% carbon & 7.75% hydrogen. It has a molar mass of 118 g. What is its empirical formula? What is its molecular formula?

6) A compound has an empirical formula of C2H5O3N. Its molar mass is 454 g. What is its molecular formula?

7) What is the empirical formula for C20H32O4N4?

8) A compound contains 69.6% carbon, 9.76% hydrogen & 20.6% oxygen. Its molar mass is 465.72 g. What is its empirical formula? What is its molecular formula?

9) A compound contains 42.044 g carbon & 7.956 g hydrogen. Its molar mass is 114.26 g. What is its empirical formula? What is its molecular formula?

10) A compound contains 30.79 g copper & 19.31 g oxygen. Its molar mass is 207 g. What is its empirical formula? What is its molecular formula?

11) A compound contains 40.9% carbon, 4.58% hydrogen & 54.5% oxygen. Its molar mass is 176.1 g. What is its empirical formula? What is its molecular formula?

12) A compound has an empirical formula of CH2O & a gram molecular mass of 180.16 g. What is its molecular formula?

13) What is the empirical formula for C6H9 ? 14) A compound contains 34.241 g carbon & 5.759 g hydrogen. Its molar mass is 28.06 g. What is its empirical formula? What is its molecular formula?

15) A compound contains 47.377% carbon, 10.625% hydrogen & 42.078% oxygen. Its molar mass is 76.05 g. What is its empirical formula? What is its molecular formula?

16) A compound contains 43.638% phosphorus & 56.362% oxygen. Its molar mass is 283.88 g. What is its empirical formula? What is its molecular formula?

17) A compound contains 27.631 g carbon, 4.880 g hydrogen, 6.446 g nitrogen & 11.043 g oxygen. Its molar mass is 434.66 g. What is its empirical formula? What is its molecular formula?

18) A compound contains 39.640% carbon, 10.834% hydrogen, 23.121% nitrogen & 26.405% oxygen. Its molar mass is 121.19 g. What is its empirical formula? What is its molecular formula?

Answers

1) C3H10OH

2) C8H16O12N4

3) FeO2

4) C105H180O30

5) C9H9

6) C10H25O15N5

7) C5H8ON

8) C27H45O6

9) C8H18

10) Cu2O5

11) C6H8O6

12) C6H12O6

13) C2H3

14) C2H4

15) C3H8O2

16) P4O10

17) C20H42N4O6

18) C4H13N2O2