Objective: In this experiment you will investigate the differences between physical changes in matter. You will be expected to perform several short exercises and observe the changes that occur during each. You will then determine if your procedure resulted in a chemical or physical change.
Safety- Caution: Hot Glass Caution: Barium Nitrate is poisonous, avoid skin contact. Caution: Silver Nitrate causes burns, avoid skin contact. Caution: do not look directly at the magnesium while it is burning. Caution: Sulfuric Acid is corrosive to the skin, avoid contact. Tie back all loose articles of clothing and/or hair.
Procedure- Prepare a table for recording your observations. For each exercise, indicate whether the reaction was chemical or physical and give the evidence from the exercises to support your answer.
! Obtain a wood splint and break into small pieces. Place several pieces in a large test tube. Using the test tube holder place over flame.
! Place a spatula of sodium chloride in 2-3 ml of water. Mix and hold over flame until the water evaporates. Examine the residue and compare it to a fresh sample of NaCl. .
! Place 5 drops of barium nitrate and 2-3 drops of sodium chromate.
! Place 5 drops of iron III chloride and add 1-3 drops of potassium thiocyanate.
! Place 5 drops of iron III chloride and add 1 or 2 drops of silver nitrate.
! Examine the nicrome wire test rod. Observe the color and the luster of the metal. Hold the wire in the flame of the burner for about two minutes.
! Using forceps, hold a piece of magnesium ribbon in the flame.
! Place about 4-5 ml dilute sulfuric acid. To the acid add a piece of zinc metal.
P Conclusion- In this lab I observed many changes in the states of matter. In more contrast I visualized physical and chemical changes. Physical changes can be observed by changes in color, size, or shape. Melting, evaporating, and freezing are three types of physical change.