Lab 2- pre-lab - online lab PDF

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Phara Ross 1. Statement The purpose of this experiment is to identify the unknown component of Panacetin. 2. Experimental plan  Recrystallize the unknown drug component from the previous experiment by boiling it with enough water to have the substance completely dissolve.  Let cool to room temperature.  Use a container that will hold the largest volume of recrystallization solvent that was calculated.  Scratch the sides of the container with a glass stirring rod in order to induce crystallization.  Cool the container in an ice bath to increase the yield of the product.  Use vacuum filtration to collect the solid.  Wash the solid with a small amount of cold water.  Dry the solid to a constant mass and weigh using a pre-weighed vial.  Grind the solid into a fine powder and divide into four equal portions.  Combine portions 1 and 2.  Mix portion 3 with an equal amount of acetanilide that is finely ground.  Mix portion 4 with an equal amount of phenacetin.  Measure the melting point for all mixtures created by recording the temperature at the first trace of liquid, and the temperature when it is completely liquid  Label vials and turn in the product to instructor  Give the actual name of the product 3. Pre-lab Questions When a pure compound is mixed with another compound, what happens to the pure compound’s melting point? -

When a pure compound is mixed with another compound, the pure compound has its melting point lowered, however, the temperature range widens.

If the solubility of acetanilide is 0.54 g/100 mL in cold water and 5 g/100 mL in hot water, what is the minimum amount of water needed to dissolve 0.83 g of acetanilide? -

g∗100.0 mL =16.60 5.0 g 16.60 mL of water is the minimum amount to dissolve 0.83g of acetanilide 0.83

Why is it standard to carry out at least two measurements of melting point? -

It is crucial to measure the melting point twice in order to double-check that the value measured was accurate. Having consistent results leaves less room for errors in the experiment

Given 1 gram of the unknown what are the minimum and maximum volumes of boiling water that might be required to fully dissolve it? -

g∗100.0 mL =82.0 mL maximum volume 1.22 g g∗100.0 mL =20.0 mLminimum volume 1.0 5.0 g 1.0...