3.5 Chemical analysis

Question 1

What is chromatography?

Answer 1

• a technique used to separate the components present within a mixture
• separates substances by making use of differences in their polarity or molecular size

Question 2

How can the identity of a component be indicated in chromatography?

Answer 2

• the distance it has traveled

- the time it had taken to travel through the apparatus (retention time)

Question 3

What is volumetric analysis?

Answer 3

using a solution of accurately known concentration in a quantitate reaction to determine the concentration of another substance

Question 4

What is a titration used to determine?

Answer 4

-accurately, the volumes of solution required to reach the end-point of a chemical reaction

Question 5

Why is an indicator used in a titration?

Answer 5

to show when the end point has been reached

Question 6

What are concordant results in a titration?

Answer 6

within 0.2cm^3 of each other

Question 7

What is a standard solution?

Answer 7

a solution of an accurately known concentration

Question 8

What is a redox titration?

Answer 8

a titration based on a redox reaction

Question 9

When would an indicator not be required when carrying out a titration?

Answer 9

when using acidified permanganate as purple permanganate solution turns to colourless when reduced