U4-1-1 - Colorimetry

Question 1

Colorimetry measures how intense the colour of a solution is. The _________ the concentration, the more intense the colour.

Answer 1

Colorimetry measures how intense the colour of a solution is. The higher the concentration, the more intense the colour.

Question 2

What measurement is taken during colorimetry?

Answer 2

Absorbance of visible light

(or transmittance)

Question 3

How do you decide which colour filter/light to use in colorimetry?

Answer 3

Must be complementary to the colour of the solution.

(e.g. solution is green = use purple filter/light)

Question 4

What must be done to the colorimeter before the absorbance of a solution can be measured?

Answer 4

Must be calibrated using a blank (only solvent in cuvette, usually deionised water)

Question 5

What is a complementary colour?

Answer 5

Opposite on the colour wheel

Question 6

Name this piece of equipment

Answer 6

Cuvette

Question 7

The absorbance measured for a solution gave a concentration higher than any of the standard solutions used to prepare the calibration graph.

What can be done to make the results more accurate?

Answer 7

Dilute the sample

OR

prepare new standard solutions of greater concentration.

Question 8

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* ____________
* plot absorbance against concentration.

Answer 8

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* plot absorbance against concentration.

Question 9

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* ____________.

Answer 9

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* plot absorbance against concentration.

Question 10

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* ____________
* measure absorbance of standard solutions
* plot absorbance against concentration.

Answer 10

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* plot absorbance against concentration.

Question 11

To draw a colorimetry calibration graph:
* ____________
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* plot absorbance against concentration.

Answer 11

To draw a colorimetry calibration graph:
* prepare a set of standard solutions with known concentrations
* calibrate colorimeter using a blank
* measure absorbance of standard solutions
* plot absorbance against concentration.