Experiments Flashcards
To test for glucose.
Materials: Tripod, Bunsen Burner, water bath (in a beaker), dissolved food solution and Benedict’s solution.
Method: Put the dissolved food solution and Benedict’s solution in a test tube and place the tube in a water bath on a tripod. Turn on the Bunsen Burner and let it boil.
Result: If the Benedict’s solution changed from blue to brick red, glucose is present. If not, glucose is not present
To test for starch
Materials: Iodine, dropper, test subject (bread, pasta and four)
Method: Use the dropper to drop some iodine on the test subject
Result: If the colour changes from orange/brown to blue/black, starch is present. If there is no change starch is not present.
To test for fats.
Materials: Brown paper, food sample (butter, oil and water)
Method: Place the sample on the paper and rub it in.
Result: If the paper becomes translucent, fat is present. If not fat isn’t present.
To test for protein.
Materials: Sodium Hydroxide, Copper Sulfate, test tube, droppers, dissolved food sample (eggs, milk and water)
Method: add the food sample, Sodium Hydroxide, and Copper Sulfate together in a test tube
Result: If it turns a violet colour, protein is present.
The conversion of chemical energy into heat energy.
Materials: Retort stand, test tube, clamp, water, thermometer, needle, cream cracker, fire
Method: Put water and a thermometer in a test tube and use a clam to attach it to a retort stand. Light the cracker on fire and place it under the test tube using a needle
Result: The temperature of the water slowly rises.
To investigate amylase on starch
Materials: Beaker, water, test tubes, starch solutions with and without amylase, iodine
Method: Put starch solution in two test tubes. Add amylase to one ( tube A). Put them in a water bath at 37degrees. Add iodine
Result: Tube A should stay yellow/red because starch is not present, Tube B should turn from red/yellow to blue/black because starch is still present.
Separating mixtures: Filtration (soil and water/sand and water)
Materials: Conical flask, water, filtration paper, beaker, soil and water.
Method: Put the soil and water into a beaker (they shouldn’t mix because they are insoluble) and place the filter paper in a conical flask. Next pour your mixture into the flask through the paper.
Result: The paper should act like a sieve and the soil won’t go through
Evaporation (salt and water or alcohol and water)
Materials: Evaporating dish, tripod, wire gauze, Bunsen burner, salt solution
Method: Place the dish on top of the wire gauze on the tripod with the Bunsen burner underneath. Put your salt solution in the dish and turn on the Bunsen burner
Result: All the water should evaporate from the dish leaving the salt in the dish
Distillation (salt and water or alcohol and water)
Materials: Liebig condenser, round-bottomed flask, tripod, Bunsen burner, thermometer, water, salt/alcohol and water
Method: Set up the apparatus ensuring that the water goes through the Liebig condenser.
Result: The water should be evaporated and leave the soluble in the flask
Chromatography
Materials: Paper, beaker, water, markers, pencil
Method: Draw a line with a ruler on the paper with the pencil. Draw 3 dots of colour with the markers. Put the paper in the beaker of water
Result: The paper should soak up the water causing the dyes in the ink to separate.
Decanting
Materials: Insoluble mixture, beaker
Method: Leave the mixture to sit in a beaker until they have separated. Pour the liquid off the top
Result: You should be left with the solid in the beaker
