Separation of Mixtures and Solids
Purpose: To become familiar with the separation of mixtures of solids Hypothesis: I will be able to separate the materials using a variety of different methods. First, separate the iron fillings using a magnet. Second, I will put the rest of the solution into water and separate the insoluble sand from the soluble salt and benzoic acid. Third, I will filter out the benzoic acid when crystalized. Lastly, I will evaporate the water away leaving crystallized salt.
1) Use your digital scale to determine the mass of your weighing dish.
2) Empty the entire mixture from the plastic bag into the weighing dish and determine the gross mass of the total mixture and weighing dish. Compute the net mass of the mixture
3) Spread the mixture into a thin layer over a sheet of paper.
4) Cut a second piece of paper into a 10-cm square. Weigh and record its mass and set it aside.
5) Wrap some plastic over the magnet. Remove the iron
powder/filings by passing the magnet over the surface of the mixture. Repeat several times to make sure you’ve collected all the iron.
6) Holding the magnet over the square of paper, remove the plastic and release all the iron to fall onto the paper. Weigh and determine the net mass of the iron powder
1) Put the remaining mixture, containing sand, benzoic acid, and table salt into your beaker and add 50 mL of distilled water.
2) 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. The benzoic acid and the sodium chloride should have dissolved and been extracted from the insoluble sand.
3) Pour the liquid while it is hot into a small paper or Styrofoam cup.
4) 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 used before. This assures that any remaining salt and benzoic acid is removed from the sand.
5) Make an ice bath by putting some crushed ice and tap water into a coffee cup or similar container that is large enough to hold your paper cup filled with the solution. Make sure the ice bath level is higher than the solution level but low enough so that no water can pour into the cup.
6) Put the cup with the solution in the ice bath. Observe the benzoic acid crystallizing out of the solution as it cools. Set these items aside until the next part of the lab.
7) Heat the sand in the beaker over low heat until the sand is completely dry. Sand has a tendency to splatter if heated too rapidly. The possibility of losing some of the sample can be reduced by covering the beaker with something and heating it slowly. Dump the sand and let it dry
8) When the sand is completely dry let the beaker to cool to room temperature.
9) After the sand and any paper towels used are completely dry, transfer the sand to a weighing dish of known mass and determine the net mass of the sand.
Separating the Benzoic Acid
First make the filtration item
1) Weigh a paper cup and record the weight.
2) Set the paper cup inside a larger coffee cup to prevent it from tipping over when you add a funnel.
3) Fold a sheet of filter paper in half and then in half again. Weigh it.
4) Open one section of the folded filter paper
5) Place the opened filter paper into the funnel and the funnel into the paper cup supported by the coffee cup. Now actually filtering
1) Remove the paper cup of salt and benzoic acid crystals from its ice bath. Fill a graduated cylinder with ~5 mL of distilled water and put the cylinder in the ice bath to chill the distilled water.
2) Swirl the cup containing the salt and benzoic acid crystals to dislodge any crystals from the sides. Then, while holding the filter paper in place, pour the items of the cup into the filter paper-lined funnel.
3) After the solution...
Please join StudyMode to read the full document