Problem 1

 

Candlewax is most often composed of hydrocarbons which contain hydrogen and carbon.  The compound C30H62 is an example.  Draw the lewis structure.  (Just kidding!)

 

a) What is the molecular mass of this substance?

 

 

b) What is the molar mass of this substance?

 

c) How many moles are there in 67 grams of candlewax?

 

 

 

 

 

d) How many grams are there in 1.58 moles of candlewax?

 

 

 

 

 

 

e) How many molecules are there in 100. grams of candlewax? 

                                                                  

 

 

 

 

f) How many atoms of carbon are there in 100. grams of candlewax? 

 

 

 

 

 

g) How many moles of carbon atoms are there in 2.00 moles of candlewax?

 

 

 

 

h) Find the volume of a candle that contains 8.52 x 1022 molecules. The density of wax is .958 g/cm3.

 

 

 

 

i)  When a candle is burned, 150.0 liters of O2 (g) is used up. How many grams of oxygen react?
Problem 2

 

A quinine molecule has the chemical formula C20H24O2N2.  It appears as a white, crystalline solid and is extracted from the bark of the chichona trees of South America.  It is used as a medicine to treat malaria victims.  In the countries unaffected by malaria, its bitter taste is most familiar in the form of tonic water. 

 

 

a) Calculate the molecular mass of a quinine molecule.

 

 

 

 

 

b) What is the number of grams in 1.00 moles of quinine?

 

 

 

 

 

 

c) Calculate the number of grams in 3.5 moles of quinine.

 

 

 

 

 

 

 

d) Calculate the number of moles in 0.473 grams of quinine.

 

 

 

 

 

 

 

e) Calculate the number of molecules in 70 grams of quinine. 

 

Problem 3

 

Acetic acid can be found in household vinegar and has the formula CH3COOH. 

 

 

a) Calculate the number of grams in 1.00 moles of acetic acid. 

 

 

 

 

 

b) Calculate the number of grams in 4.1 moles of acetic acid. 

 

 

 

 

 

 

c) How many moles are in a sample of acetic acid containing 9.25 x 1025 molecules?

 

 

 

 

 

 

 

 

d) How many oxygen atoms are there in 85 grams of acetic acid? 

 

Problem 4

 

Aspartame is sold under the name NutraSweet and has the formula C14H18O5N2. 

 

 

a) How many grams are in 1.00 moles of aspartame? 

 

 

 

 

 

 

b) How many molecules are there in 2.00 grams of aspartame? 

 

 

 

 

 

 

 

c) How many moles of hydrogen atoms are there in that 2.00 gram sample? 

 

 

 

 

 

 

 

d) If a sample contains 2.45 x 1022 molecules of aspartame, how many moles of aspartame are present?