Effect of inserting a single sample on the spectrum

1. Why do you use a single wavelength to observe change in absorbance?
2. What affects the absorbance of a sample solution?
3. What happens on a spectrophotometer when the concentration of the sample increases?
4. What does an absorbance of 1 mean?

Why do you use a single wavelength to observe change in absorbance?

The wavelength of maximum absorbance is used when determining the concentration of a colored solution since at this wavelength a slight change in concentration allows for a significant change in the absorbance of light.

What affects the absorbance of a sample solution?

The two main factors that affect absorbance are concentration of the substance and path length. Relation between concentration and absorbance: Absorbance is directly proportional to the concentration of the substance. The higher the concentration, the higher its absorbance.

What happens on a spectrophotometer when the concentration of the sample increases?

If the concentration of solution is increased, then there are more molecules for the light to hit when it passes through. As the concentration increases, there are more molecules in the solution, and more light is blocked. This causes the solution to get darker because less light can get through.

What does an absorbance of 1 mean?

An absorbance of 1 happens when 90% of the light at that wavelength has been absorbed, which means that the intensity is 10% of what it would otherwise be. In that case, I₁/I₀ is 10/100 = 0.1) and -log₁₀ of 0.1 is 1. Absorbance is a logarithmic scale similar to the Richter Scale used for earthquakes.