Physical And Chemical Changes

CHEMISTRY I
Unit 1. Introduction to Chemistry

Lab Session 1: Physical and chemical changes

Aim. Observe and accurately identify the changes experienced by iodine, magnesium and sugar asphysical or chemical.

 Materials.
Materials
Household
Laboratory

Household

Fannel
Lighter

Ice
Sugar

2 50ml Beaker
1 Gas Burner
1 W atch Dish
1 Crucible Tongs

ReactantsLaboratory
Solid Iodine
Magnesium Ribbon
Concentrated Sulphuric Acid

 Methodology.
A. Activity 1. Physical Changes.
1. Place a few iodine crystals inside the 50ml beaker and describe their properties.2. Place the ice on the watch dish and put it on top of the beaker as a lid.
3. Heat the beaker up with the help of the gas burner (Use the crucible tongs to hold the
beaker on the fire).
4.Observe any changes on the Iodine and in the colour of the gas.
5. Place the beaker on the bench and let it cool down.
6. Retrieve the watch dish.
7. Observe the bottom of the watch dish (the side thatwas in contact with the gas).
8. Record and photograph all your observations.
B. Activity 2. Chemical change-sugar
 This experiment must be performed inside the fume hood.
1. Place a spoonful ofsugar on the beaker.
2. Carefully, add a small amount of concentrated sulphuric acid to the sugar.
3. Close the fume hood.
4. Observe during 3minutes
5. Photograph and record any changes in thesugar.
C. Activity 3. Chemical change-Magnesium ribbon
1. Light the gas burner up
2. Take the magnesium rubber with the crucible tongs and place it on the fire.
3. Draw and record yourobservations.
 Key points & questions to be used in the discussion of the lab report.
1. Iodine activity.
a. Was the internal structure of iodine changed?
b. What type of change (physical or chemical) didthe iodide and ice suffered?
Explain why.
c. Explain which other changes (within the physical or chemical framework) were
experienced by iodine and ice.
2. Sugar activity.
a. Did the internal...