problem 1: Classify each of the given materials as a homogeneous mixture, a heterogeneous mixture, a pure compound, or an element. In some cases, more than one category might apply.
a) Contents of a completely full bottle of a carbonated beverage before the cap is removed.
b) Contents of a completely full bottle of a carbonated beverage shortly after the cap is removed.
c) A penny minted after World War II.
d) Air mass above Mt. Baldy on a dry, September day.
e) Air mass above Mt. Baldy as a storm front moves in.
f) Solid contents of a salt shaker.
g) Non-gaseous contents of a bottle of distilled water at 25°C.
h) Non-gaseous contents of a bottle of distilled water at 0°C.
problem 2: One can describe the properties of a large class of solid compounds with a model in which variable numbers of atoms of one element fill the holes formed by a lattice (regular arrangement) of atoms of a second element. Which empirical laws are needed to be modified by the existence of this class of compounds? Which parts of the Daltonian atomic-molecular model?
problem 3: Photochemistry is the study of the effect of light on atoms and molecules. Atoms, for illustration, can be selectively excited by the absorption of light and excited atoms react differently than unexcited atoms. What prediction regarding the reactivity of excited atomic species would be drawn from the postulate(s) of Dalton's atomic-molecular model?
problem 4: Recommend a physical method for separating the components of the given mixtures:
a) Grains of magnetite (a magnetic ore of iron) and quartz (a naturally occurring compound of silicon and oxygen which is the primary constituent of sand)
b) A solution of paraffin wax (grandmother used this hydrocarbon to seal jars of strawberry jam) in octane (the main constituent in gasoline)