Exp. 4.1 Dissolving a Solid in Water Name ______________________

I. Purpose:

To begin learning about solutions, concentration of solution, saturation. This will be accomplished using solutions that have color.

II. Procedure:

1. Place 5.0 mL of water in one test tube and 20.0 mL of water in another.

2. Add 0.30 g of orange solid to each tube, then stopper each and shake thoroughly.

3. Answer the following questions:

a. Did all the solid dissolve in each test tube?

b. Is the color uniform within each test tube?

c. Do you think that each mL of solution contains the same mass of dissolved material?

(within each test tube separately)

d. Both test tubes contain the same mass of dissolved material, but is the shade of color the

same in both test tubes?

4. Try to dissolve another 0.30 g of orange solid in each test tube – be patient!

5. Since the solution may cool as the solid dissolves, try to keep the temperature fairly constant by

warming the test tube with your hand.

e. Did 0.60 g of solid dissolve as well in 5.0 mL as in 20.0 mL of water?

f. Is the color still uniform in each solution?

g. Is the shade of color the same in the two test tubes?

6. Add another 0.30 g of the orange solid to each solution, and again mix thoroughly.

h. How much orange solid is in each test tube?

i. What do you observe?

j. How much orange solid do you think there would have to be in the 20.0 mL of water so that

not all of it will dissolve?

7. Clean the test tubes and stoppers thoroughly.