Understanding the Law of Definite Proportions

Who was the chemist that formulated the law of definite proportions?

• Antoine Lavoisier

• Dmitri Mendeleev

• Joseph Proust

• John Dalton

What is the mass ratio of oxygen to hydrogen in water?

• 1:2

• 8:1

• 2:1

• 1:8

If you start with 18.0 g of water, how much oxygen would you obtain upon decomposition?

• 2.0 g

• 16.0 g

• 18.0 g

• 8.0 g

Why does water always have the same mass ratio of hydrogen to oxygen?

• Because water is a universal solvent

• Due to the specific masses of hydrogen and oxygen atoms

• Because water is always pure

• Due to the conservation of mass

What is the chemical formula for water?

• H2O2

• OH2

• HO

• H2O