DM 5 - Energy and Matter

Question 1

What is a colorimeter?

Answer 1

A colorimeter measures the intensity of light passing through a solution i.e. it measures the absorbance of light

Question 2

What is a visible spectrophotometer?

Answer 2

It measures the amount of light transmitted or reflected, when incident on a solution, as a function of wavelength

Question 3

How can you use a colorimeter/visible light spectrophotometer to measure the concentration of a transition metal solution?

Answer 3

• First, create a series of solutions of known concentration with the transition metal ion. Measure their absorptions using a colorimeter or visible spectrophotometer
• Create a ‘calibration curve’ which is a graph of absorption (y-axis) against concentration (x-axis)
• This curve can then be used to identify unknown concentrations of transition metal solutions by their absorptions