Physical & Chemical Properties

Substance: Mg

Color: red-brown

Odor: metallic

Effect of Heat: crunched

Litmus test: solid

Substance: Cu

Color: reddish brown

Odor: metallic

Effect of Heat: holes developed

Litmus test: purple

Substance: Zn

Color: silvery

Odor: metallic

Effect of Heat: develops holes and steams

Litmus test: purple

Substance: NaCl

Color: opaque white

Odor: salty

QUESTIONS:

A - Did you observer any chemical changes in this experiment?
yes

B - What evidence did you use to decide that something was a chemical change?
element and reactions

 

C - Give at least two examples of chemical changes you observed.
steaming, formations

D - Classify the following properties of sodium metal as physical or chemical:

            Silver metallic color – physical

            Turns gray in air – chemical

            Melts at 98^oC - physical

            Reacts explosively with chlorine - chemical

E - Classify the following changes as physical or chemical:

            Water freezes at O^oC - physical

            Baking soda when combined with vinegar produces bubbles:- chemical

            Mothballs gradually disappear at room temperature – physical

            Ice cubes in a freezer get smaller with time – physical

            Baking soda loses mass as it is heated – chemical

            Tarnishing of silver – physical

F - How would you show that dissolving table salt is a physical change?

            Dehydrate the solution