Milk Fat Lab

Introduction

According to Beer’s Law the percent of light that passes through a liquid medium is related to the medium’s thickness, color, and concentration. When the thickness and color of the media is kept constant, the quality of the light coming out of the medium should directly correlate to the concentration of particles in the medium. The purpose of this investigation is to demonstrate Beer’s Law using milky water and see how well light is scattered by the fat globules that become suspended in the water as a result.

Hypothesis

As more milk fat is added to the water, the light passing through it will become dimmer because there will be more particles to scatter the light. Thus, the spot light on the paper will become smaller and a beam of light will become visible through the media.

Procedure:

1. Fill one 2 Liter tank completely with water.
2. On one end of the tank place a piece of white paper, and on the other end place a flashlight.
3. Turn on the flashlight and observe the light striking the paper and any beam of light visible through the water.
4. Use a dropper and drop a small amount of Half and Half milk into the tank.
5. Repeat step 3.
6. Repeat steps 4, 5 until the tank is too concentrated to make a noticeable difference in the light quality.

Observations

Before the milk fat was added, the light clearly transmitted through the tank; the paper had a spot of light that was bright and big. When milk was added to the tank, the fat globules scattered the light. The low transmittance of the light meant a high concentration of milk fat.

Did you know

Why is the sky blue?
The reason the sky is blue is because blue light is scattered most by the atmosphere. Blue light scatters because it has a shorter frequency, so when it hits a particle, it scatters. On the other hand, red light has a longer wavelength, so when it hits a particle, it transmits light. That’s also why our sunsets are never blue, but red.