1. Separating out the Iron
a. Use the digital scale to determine the mass of the weighing dish and record in the table.
b. Empty the mixture of solids from the plastic bag into the weighing dish and determine the gross mass of the total mixture and weighing dish and record in the table. Compute the net mass of the mixture and record in the table.
c. Spread the mixture into a very thin layer over a full sized piece of paper.
d. Cut a second piece of paper into a 10-cm square. Weigh and record its mass and set it aside.
e. Wrap a small square of clear plastic over the magnet. Remove the iron powder/filins by passing the magnet closely over the surface of the entire mixture. Repeat several times to make sure you’ve collected all the iron.
f. Holding the magnet over the 10-cm square of paper, carefully remove the plastic and allow all the iron to fall onto the paper. Weigh and determine the net mass of the iron powder/filings.
2. Separating out the Sand
a. Put the remaining mixture, containing sand, benzoic acid, and table salt into your beaker and add 50 mL of distilled water.
b. Set up the beaker stand and burner fuel and heat the beaker of solids and water to near boiling. Stir the mixture to make sure all soluble material dissolves. At this point, the benzoic acid and the sodium chloride should have dissolved and been extracted from the insoluble sand.
c. Decant the liquid while it is hot into a small plastic cup.
d. Pour another 10 to 15 mL of distilled water into the beaker containing the sand, bring the mixture to a boil, and decant again into the same cup.
e. Make an ice bath by placing a small amount of crushed ice and tap water into a coffee cup or similar container that is large enough to hold your paper cup of benzoic acid and salt solution.
f. Place the cup containing the water solution of benzoic acid and salt into the ice bath. Observe the benzoic acid crystallizing out the solution as it cools. Set this water bath assembly aside until the next section.
g. Let the sand air-dry over night until completely dry. Weigh the sand and determine the net mass.
3. Separating out the Benzoic Acid
a. Weigh a small cup and record its mass.
b. Fold a sheet a filter paper in half and then in half again and weigh it. Open one section of the folded filter paper as shown in the bottom illustration and place into the funnel.
c. Remove the cup from the ice bath and swirl to dislodge any crystals from the sides. Then, while holding the filter paper in place and open, pour the contents of this cup into the filter paper-lined