Chemical Composition and Properties

This video tutorial introduces the concept of relative formula mass, explaining how it is calculated using atomic mass units. It covers the use of chemical formulas and the periodic table to determine the mass of individual atoms. The tutorial provides examples, including water and chromium sulfate, and offers practice problems with solutions to reinforce learning.

What is the relative formula mass of a substance measured in?

• Atomic mass units

• Kilograms

• Grams per liter

• Moles per liter

In a chemical formula, what do the subscripts indicate?

• The number of molecules

• The temperature of the reaction

• The type of chemical bond

• The number of each type of atom

Where can you find the mass numbers of elements?

• On a molecular model

• In a laboratory manual

• On the periodic table

• In a chemistry textbook

What does the atomic number represent on the periodic table?

• The number of neutrons in an atom

• The mass of the atom

• The number of protons in an atom

• The number of electrons in an atom

How many hydrogen atoms are in a molecule of water?

• Three

• Two

• Four

• One

What is the relative formula mass of water (H2O)?

• 22 atomic mass units

• 20 atomic mass units

• 16 atomic mass units

• 18 atomic mass units

In the compound chromium(III) sulfate, how many sulfate ions are present?

• One

• Two

• Three

• Four

What is the first step in calculating the relative formula mass of a compound?

• Finding the atomic number

• Identifying the chemical formula

• Measuring the compound's volume

• Calculating the density

How many carbon atoms are in a molecule of glucose (C6H12O6)?

• Six

• Seven

• Four

• Five

What is the relative formula mass of iron(III) oxide (Fe2O3)?

• 120 atomic mass units

• 160 atomic mass units

• 140 atomic mass units

• 180 atomic mass units