# Beer Lambert Law Lab

Purpose:

The purpose of this lab is to prove the Beer Lambert Law experimentally. The various solutions used for this experiment are tap water mixed with food colouring, Introduction:

The Beer Lambert Law shows the relation between absorbance of light of an object, the molar absorptivity, the concentration of the substance, and the distance the light travels. The Beer Lambert Law states that there is a linear relationship between the concentration of a solution and the absorbance of said solution. If there is a linear relation, the resulting graph should be a straight line. If the graph is a straight line, this would prove the Beer Lambert Law and fulfill the purpose of this lab. This experiment involves tap water mixed with food colouring but at various concentrations of the solution. Hypothesis:

It is expected that the absorbance of a substance can be calculated by the formula, A = epsilon * l * c. (A = Absorbance, Epsilon = molar absorptivity, l = distance light travels through solution, C = concentration of solution.) It is expected that this linear relation between absorbance and concentration will be found as true as predicted by the Beer Lambert Law which states that there is a linear relation between absorbance and concentration. Variables:

Independent: Concentration of liquid

Dependant: Absorbance of the liquid

Controlled: Tap Water, Food Colouring (Amount does not change), same test tube, temperature of solution, optimal wavelength of solution (when measuring absorbance). Materials/Apparatus:

1. Blue Food Colouring

2. Spectrometers

3. Spectrovis

4. Tap Water

5. Cuvette

6. Beakers

Method/Procedure:

1. Made a stock solution (100%) with water and food colouring. 2. A 1/2 concentration solution was made by taking 200 mL of the stock solution and diluting it with 200 mL of water. 3. A 1/4 concentration solution was made by taking 100 mL of the stock solution and diluting it with...

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