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21 Cards in this Set
- Front
- Back
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State the metals ions that we need you need to know the flame test for and the mnemonic |
Lithium Sodium Potassium Calcium Copper |
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State the 2 ways of identifing if compounds contain metal ions |
- Flame tests - Flame emission spectroscopy |
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Describe how we use test unknown compounds for metal ions in a flame test 3 marks |
- Place small amount of chemical onto wire - Place end of chemical into blue bunsen flame - The colour of the flame determines which metal ion is present |
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What colour flame must the bunsen burner be on for flame tests to work |
Blue |
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Which is on higher the blue flame or red flame on a bunsen burner |
Blue flame |
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What is crimson a combination of colours of |
Pink at top Blue at bottom |
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What is the mnemonic and the flame tests for the colours of flames & metal ions |
Lithium. = Crimson flame Sodium. = Yellow flame Potassium. = Lilac flame Calcium: = Orange/red flameCopper. = Green flame
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What is the mnemonic for the colours of the flames |
C Y L O G
See why log |
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State 2 disadvantages for using flame tests to identify metal ions |
- Colour can be difficult to make out (especially if low concentration of metal ion is used) - If a unknown compound contains a mixture of metal ions some flame colours can be masked (on spec) |
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What does it mean if a flame colour is masked and explain how this is a disadvantage whne identifying metal ions |
It means it is not shown: meaning the colour of 1 metal ion can mask the other colour flames so we don't know all the metal ions of the sample |
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What type of method is flame emission spectroscopy |
A instrumental method |
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What is a meant by a instrumental method |
The process is carried out by a machine |
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Explain how flame emission spectroscopy tells us the concentration of a metal ion |
The lines become more intense at a higher concentration |
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State the 3 characteristics of instrumental methods |
Rapid, sensitive, accurate |
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Compare the advantages of instrumental methods with flame test and explain ecah briefly |
More rapid: (analyse samples faster than flame tests) More sensitive: (Work on a tiny sample of metal compound) More accurate: (More likely to be the correct metal ion) |
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What 2 things does flame emission spectroscopy tell us |
- Can be used to identify the metal ion - Can be used to find the concentration of a metal ion |
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What does the positioning of the lines tell us on a flame emission spectroscopy |
They are specific for each given metal ion so they will tell us what metal ion is present |
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How can we check which metal ion is present on a flame emission spectroscopy |
The positioning of the lines are specific for a given metal ion |
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Describe the process of flame emission spectroscopy 3 marks |
- Sample metal ion is placed into flame - Light given out is passed into a machine called a spectroscope - Spectroscope converts light into a line spectrum |
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State what the machine is called in flame Emission spectroscopy and its function |
Spectroscope: Converts light into a line spectrum |
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Draw out the 3 stages of flame emission spectroscopy |
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