C12 Chemical Analysis

Question 1

What colour will the flame turn when testing for lithium (if lithium is present)?

Answer 1

Red

Question 2

What colour will the flame turn when testing for sodium (if sodium is present)?

Answer 2

Yellow

Question 3

What colour will the flame turn when testing for potassium (if potassium is present)?

Answer 3

Purple

Question 4

What colour will the flame turn when testing for calcium (if calcium is present)?

Answer 4

Orange

Question 5

What colour will the flame turn when testing for copper (if copper is present)?

Answer 5

Blue/green

Question 6

How does the “cotton bud procedure” work?

Answer 6

1) Wet a cotton bud with deionised water
2) Dip the cotton bud into the solid you are testing
3) Hold the cotton bud over the flame to identify what colour it changes to

Question 7

How does the nichrome wire procedure work?

Answer 7

1) Clean a platinum or nichrome wire by dipping it into hydrochloric acid and then holding over a hot bunsen flame

2) Repeat this until the wire produces no colour in the flame

3) When the wire is clean, moisten again with some hydrochloric acid and then dip it into a small amount of the solid you are testing

4) Place the wire back over the flame and identify what colour the flame changes to