Pure substance, a heterogenous mixture, or a homogenous mixture

1. For the following substances, state whether they are most likely a pure
   substance, a heterogenous mixture, or a homogenous mixture (8 points)
   a) Tap water
   b) Beach sand
   c) Copper wire
   d) A suspiciously cheap "gold" ring sold at the University center by some
   guy named "Rainbow"
2. Given the following information write the complete chemical symbol
   (i.e. complete with appropriate superscripts) for each element or ion (8
   points)
   Number of
   Neutrons
   Number of
   Electrons
   Number of
   Protons
   Symbol
   13 12 12
   19 18 17
   6 2 5
   35 27 29
3. Given the following chemical symbols for an atom or ion, write down
   the number of protons, neutrons and electrons (8 points)
   Chemical symbol Number of
   Protons
   Number of
   Neutrons
   Number of
   Electrons
   18O
   2-
   40Ca2+
   40Ar

131I

1. Write down the chemical formula for an ionic compound of the
   following combinations of metals and nonmetals (8 points)
   a) Sodium and Sulfur
   b) Calcium and Chlorine
   c) Aluminum and Oxygen
   d) Potassium and Bromine
2. Provide the names for the following chemical compounds or ions (8
   points)
   a) HClO
   b) H2SO4
   c) IO4

• d) SO4
  2-

1. Draw chemical structures (i.e. use lines to indicate bonds between
   atoms, and show all atoms) for the following organic molecules or
   functional groups (8 points)
   a) Butane
   b) Cycloheptane
   c) Draw an alcohol functional group (use the letter 'R' to represent the
   organic part(s) of the molecule)
   d) Draw a carboxylic acid functional group (use the letter 'R' to represent
   the organic part(s) of the molecule)
2. Determine the percentage by mass of C, H and O in propanol (C3H7OH;
   or C3H8O) (8 points)
3. If 37.8g of propanol is combusted, how many grams of carbon dioxide
   is produced? Be sure to include the balanced chemical equation for the
   combustion of propanol as part of your answer (12 points)
4. If 48.7 grams of magnesium chloride is dissolved in 4.35 L of water,
   what is the resulting molarity of the magnesium chloride solution? (6
   points)
5. Indicate whether the following ionic compounds are most likely
   soluble or insoluble in aqueous solution (8 points)
   a) NaBr
   b) NH4OH
   c) AgCl
   d) Mg(OH)2
6. Write the balanced molecular equation and the net ionic equation for
   the neutralization reaction between magnesium hydroxide, Mg(OH)2, and
   hydrochloric acid, HCl (10 points)
7. What are the oxidation numbers assigned to the following atoms of
   each element? (8 points)
   a) CH3COOH
   b) ClO- c) S8

Sample Solution