Messing With Mixtures Part A - The Science Spot (Page 3 of 3) in pdf

Messing With Mixtures Part A - The Science Spot Page 3

Part D: See The Light

(16) Create 4 different mixtures by following the steps below.

Step 1: Mix 10 grams of salt with 100 mL of water in a ziploc bag. Label the bag as D-1.

Step 2: Mix 10 grams of flour with 100 mL of water in a ziploc bag. Label the bag as D-2.

Step 3: Mix 10 grams of Kool-Aid powder with 100 mL of water in a ziploc bag. Label the bag as D-3.

Step 4: Mix 10 grams of dirt with 100 mL of water in a ziploc bag. Label the bag as D-4.

(17) Shine a flashlight through each bag. What do you observe about each mixture?

D-1 = Salt & water

D- 2 = Flour & water

D-1 = Kool-Aid powder & water

D-1 = Dirt & water

(18) Read the following information from the Columbia Encyclopedia, then answer the questions.

One property of a colloid that distinguishes it from a true solution is that the particles in a

colloid scatter light. If a beam of light passes through a colloid, the light is reflected or scattered by

the particles in the colloid and the path of the light can be observed. When a beam of light passes

through a true solution there is so little scattering of the light that the path of the light cannot be seen

and the small amount of scattered light cannot be detected except by very sensitive instruments. The

scattering of light by colloids, known as the Tyndall effect, was first explained by the British

physicist John Tyndall.

(A) Which mixtures would be classified as colloids? __________ & ___________

(B) Which mixtures would be classified as solutions? ___________ & ____________

Bag _____

Solute = __________________ Solvent = _____________________

Bag _____

Solute = __________________ Solvent = _____________________

(D) Describe a situation in which you would observe the Tyndall Effect.

Messing With Mixtures Part A - The Science Spot Page 3