Chemical Analysis

Question 1

What is a standard solution?

Answer 1

A solution of accurately known concentration

Question 2

In a titration what is meant by concordant results?

Answer 2

Volumes within 0·2 cm3 are considered to be concordant at Higher

Question 3

In a titration what is meant by the end point?

Answer 3

The end-point is the point at which the reaction is just complete

Question 4

In a titration why is an indicator used?

Answer 4

An indicator changes colour showing the end point

Question 5

Describe in detail how a burette should be prepared and set up, ready to begin a titration.

Answer 5

1. Rinse the burette – rinse the burette with the required solution/with the solution to be put in it.
2. Fill burette above the scale with solution
3. Filter funnel used should be removed
4. Tap opened / some solution drained to ensure no air bubbles

Question 6

Why is an indicator not required for some redox titrations such as ones using potassium permanganate?

Answer 6

Potassium permanganate is coloured and loses colour when it is reduced.

Question 7

What is chromatography used for?

Answer 7

To separate substances in complex mixtures.

Different substances travel at different speeds, so some move further than others in a given time.