Physical And Chemical Change Of Six White Substances

Jacqueline Sanders             Myra Bradwell School
                               7736 South Burnham
                               Chicago, IL 60649
                               (312) 535-6600

Objectives:  

 (1).  To determine whether the reaction between selected white substances and 
       vinegar, water and iodine are chemical or physical. 
 (2).  Make a hypothesis using observation, touch and smell. 
 (3).  Through chemical analysis the students will be able to determine what 
       happens to each of the substances - i.e. will they (a) clump or clot;
       (b) bubble or fizz; (c) separate; (d) give off a sweet or foul odor;
       (e) change colors. 


Apparatus Needed:

  (1).  Petri dishes or Egg cart.
  (2).  Six white substances:  powdered sugar, salt, baby powder, cornstarch, 
        baking soda and plaster.
  (3).  Water
  (4).  Vinegar
  (5).  Iodine

CAUTIONS TO STUDENTS: 

Use of iodine can cause damage to clothing, irritation to skin and breathing 
iodine can be hazardous to your health.  

Strategy:


Test each substance individually with the following materials:  water, vinegar 
and iodine.  Make a hypothesis using observation, touch and smell. 

Conclusion:

The substances have been identified as follows: powder sugar, salt, baby powder,
cornstarch, baking soda and plaster.

Vocabulary:

Physical Change- is one in which the appearance of matter changes but its 
properties and makeup remain the same.

Chemical Change- is a change that produces one or more kinds of matter that are 
different from those present before the change.

Chemical Property- the ability of substances to undergo or resist chemical 
change. 

Observation- is an examination of something in nature.  Observing is more than 
seeing, it requires attention to details.  It is a skill that requires patience 
and practice.