Question

How many molecules of carbon dioxide are in 113 grams of carbon dioxide (CO2)?

Select one:
a. 1.88 x 10^-22 molecules
b. 6.80 x 10^25 molecules
c. 2.57 molecules
d. 1.55 x 10^24 molecules

Answer 1

The correct answer is d. 1.55 x 10^24 molecules. Carbon dioxide, CO2, has one carbon atom and two oxygen atoms. The molar mass of CO2 is 44.01 g/mol. Therefore, 113 g of CO2 contains 113/44.01 = 2.56 moles of CO2, which is 2.56 x 6.022 x 10^23 = 1.55 x 10^24 molecules of CO2.