Essential Laboratory Procedures and Chemical Experiments

Porcelain Dish Experiment

Procedure for Porcelain Dish

• Heat the charcoal in a porcelain dish.
• Add the wine from the first beaker, which initially held the charcoal.
• Add the hot charcoal to the wine and then remove it. Place the flask under a clean funnel and filter the contents into the flask.
• Place a quantity of pure wine (IVF) into the first test tube.
• Into the second test tube, add a quantity of discolored, filtered wine.
• Add the wine over charcoal.
• Mix and let stand for a couple of minutes.
• Filter.

Determination of Gas Density

Materials for Gas Density Experiment

• Erlenmeyer flask
• Glass tube
• Silicone or rubber tubing
• Crystallizing dish
• Support stand and ring
• Sample container
• Cap with a hole

Reagents for Gas Density Experiment

• Half an effervescent tablet
• Distilled water
• Limewater

Procedure for Gas Density Determination

• Weigh the effervescent tablet.
• Weigh the flask with water.
• Add the tablet to the flask and immediately close it, noting the initial water level in the sample container.
• Once gas stops passing into the sample container, note the final water level.
• The difference between the initial and final water levels gives the volume of gas in mL.
• Empty the Erlenmeyer flask of water and tablet remains.
• The difference between the initial mass (flask + water + tablet) and the final mass (flask + water + tablet remains) yields the mass of gas in grams.
• The density will be calculated as: Mass of gas (g) / Volume of gas (mL).

Chromatography Principles and Application

Chromatography is a separation technique based on the different speeds at which substances move through a porous medium, carried by a moving solvent. We will use this technique to separate the pigments found in commercial paint.

Materials Needed for Chromatography

• A strip of filter paper
• Markers or pens of different colors
• A glass beaker or jar
• A small amount of alcohol

Procedure for Chromatography Experiment

• Cut a rectangle of filter paper.
• Fold it in half like a book along its longest side. At the lower end, draw a straight pencil line half a centimeter from and parallel to the bottom edge.
• On the drawn pencil line, make three distinct colored dots, spaced equally apart. Place the paper into a beaker containing about one cm of ethanol, ensuring the solvent level is below the pencil line. Allow the setup to sit until the next day.

Theoretical Foundations of Chromatography

In paper chromatography, there are distinct phases:

• Mobile phase: Consists of the solvent that ascends the paper, also known as the eluent.
• Stationary phase: Formed by the water content of the filter paper, which retains each of the color components of the analyte differently.

Examples of stationary phases: Paper, chalk, etc.

Examples of mobile phases: Eluent, petroleum, gasoline.

Simulation of an Artificial Lung

First, an artificial lung can be made from a plastic bottle. Puncture the bottle's base about one-third of the way up. Then, puncture the cap. Cover the hole in the bottle with tape.

Fill the bottle with water to a determined height. Insert cotton, then attach the cap and a straw, sealing it with plasticine to prevent air leaks. Hold the straw and remove the tape. When the straw is removed and water stops pouring out, replace the tape and leave it for one day.