Understanding the Law of Definite Proportions

This video tutorial covers the law of definite proportions, explaining that compounds have a constant chemical composition by mass. Using carbon dioxide as an example, the video demonstrates how to calculate the mass of oxygen given different amounts of carbon. It then provides practice problems involving sodium fluoride, methane, and aluminum oxide, showing how to use conversion factors and proportions to solve these problems.

What is the atomic mass of carbon as found on the periodic table?

• 18

• 16

• 12

• 14

If a sample of carbon dioxide contains 24 grams of carbon, how many grams of oxygen are present?

• 64 grams

• 48 grams

• 32 grams

• 96 grams

What is the ratio of the mass of oxygen to the mass of carbon in carbon dioxide?

• 2.67

• 3.00

• 1.50

• 1.33

How many grams of oxygen are present with 30 grams of carbon in carbon dioxide?

• 70 grams

• 90 grams

• 80 grams

• 60 grams

What is the atomic mass of sodium as per the periodic table?

• 19

• 23

• 21

• 25

In sodium fluoride, if there are 35 grams of sodium, how many grams of fluorine are present?

• 30 grams

• 28.9 grams

• 32 grams

• 25 grams

What is the atomic mass of hydrogen?

• 4

• 3

• 2

• 1

In methane, how many grams of carbon are present if there are 42 grams of hydrogen?

• 150 grams

• 126 grams

• 84 grams

• 100 grams

What is the atomic mass of aluminum?

• 27

• 30

• 24

• 25

In aluminum oxide, if there are 19 grams of oxygen, how many grams of aluminum are present?

• 21.5 grams

• 19 grams

• 23 grams

• 25 grams