The law of fixed composition

Quiz: Dalton's Atomic Theory

1. Hydrogen combines with oxygen in a 1:8 weight ratio to form water. If every molecule of water contains two atoms of hydrogen and one atom of oxygen, an atom of oxygen must weigh:

	16 times the mass of a hydrogen atom		1/16 times the mass of a hydrogen atom
	1/8 times the mass of a hydrogen atom		8 times the mass of a hydrogen atom

2. Hydrogen combines with fluorine in a 1:19 weight ratio to form hydrogen fluoride. If every molecule of hydrogen fluoride contains one atom of hydrogen and one atom of fluorine, an atom of fluorine must weigh:

	19 times the mass of a hydrogen atom		1/19 times the mass of a hydrogen atom
	1/38 times the mass of a hydrogen atom		38 times the mass of a hydrogen atom

3. 1.008 grams of hydrogen combines with 35.453 g of chlorine to form 36.463 g of a pure compound (hydrogen chloride). Dalton's explanation for this experimental fact might be:

	chlorine accepts hydrogen's electron to form polar covalent hydrogen chloride
	hydrogen and chlorine atoms aren't created or destroyed in the process so the reactant mass is the same as the product mass.
	hydrogen and chlorine atoms always combine in a 1:35 ratio.
	this is a simple mixture of elements because the ratio isn't a whole number ratio
	one atom of hydrogen combines with 35.453 atoms of chlorine in this reaction

4. Dalton based his relative atomic weight scale on:

oxygen

hydrogen

carbon

helium

lithium

5. Dalton said that elements are different distinguished from each other by:

	the density of their solid forms		the shapes of their atoms
	the charge on their ions		the weights of their atoms

Dalton's Atomic Theory
Page 1: Introduction
Page 2: Dalton's assumptions Five steps forward and one step back.
Page 3: Atoms in compounds An "invisible hand" fixes atom ratios in compounds
Page 4: Atoms in reactions Dance of the atoms
Page 5: Learning check Take a quiz on Dalton's Atomic Theory
Page 6: References and resources

General Chemistry Online! Quiz