Flame Test Lab.pdf
Flame Test Lab.pdf Flame Test Lab.pdf
Mrs. E. Dharmai SCH3U1 Flame Test Lab Each element has a unique line spectrum. We can use these fingerprints to determine metals present in unknown metallic compounds. Flame tests are used to do so. When an unknown sample is heated, the resulting flame colour can be compared to a chart of known flame colours. Flame Test: a diagnostic technique in which a metallic compound is placed in a flame and the colour produced is used to identify the metal in the compound. This lab will be conducted in 2 parts: a) Creating a flame test key from known metallic compounds b) Identifying an unknown metal in a compound by using the flame test key Materials: Goggles Nichrome test wire Test tubes Test‐tube rack Bunsen burner Hydrochloric acid, dilute Samples of the following solids: Sodium chloride Barium chloride Calcium chloride Strontium chloride Lithium chloride Potassium chloride Copper (II) chloride Various unknown metallic compounds Procedure: Part A: Creating a Flame Test Key 1. Obtain your solid samples and 5 mL of hydrochloric acid solution. 2. Light the Bunsen burner and adjust it until you get a blue flame. 3. Clean the nichrome wire by dipping it into the hydrochloric acid and then holding the wire in the flame until the wire adds no colour to the flame. 4. Pick up a small amount of solid sodium nitrate with the wire loop. Hold the end of the wire in the flame. Record your observations. 5. Clean the wire as in step 3. 6. Repeat steps 4 and 5 with the remaining known samples to complete your flame test key. Part B: Identifying Metals in Unknown Metallic Compounds 1. Obtain samples of the unknown metallic compounds. 2. Test each sample using the steps 3 and 4 from above. Record your observations and determine the metal in the unknown samples.
Mrs. E. Dharmai<br />
SCH3U1 <strong>Flame</strong> <strong>Test</strong> <strong>Lab</strong><br />
Each element has a unique line spectrum. We can use these fingerprints to determine metals<br />
present in unknown metallic compounds. <strong>Flame</strong> tests are used to do so. When an unknown<br />
sample is heated, the resulting flame colour can be compared to a chart of known flame<br />
colours.<br />
<strong>Flame</strong> <strong>Test</strong>: a diagnostic technique in which a metallic compound is placed in a flame and the<br />
colour produced is used to identify the metal in the compound.<br />
This lab will be conducted in 2 parts:<br />
a) Creating a flame test key from known metallic compounds<br />
b) Identifying an unknown metal in a compound by using the flame test key<br />
Materials:<br />
<br />
<br />
<br />
<br />
<br />
<br />
Goggles<br />
Nichrome test wire<br />
<strong>Test</strong> tubes<br />
<strong>Test</strong>‐tube rack<br />
Bunsen burner<br />
Hydrochloric acid,<br />
dilute<br />
<br />
<br />
<br />
<br />
<br />
<br />
Samples of the<br />
following solids:<br />
Sodium chloride<br />
Barium chloride<br />
Calcium chloride<br />
Strontium chloride<br />
Lithium chloride<br />
<br />
<br />
<br />
Potassium chloride<br />
Copper (II) chloride<br />
Various unknown<br />
metallic compounds<br />
Procedure:<br />
Part A: Creating a <strong>Flame</strong> <strong>Test</strong> Key<br />
1. Obtain your solid samples and 5 mL of hydrochloric acid solution.<br />
2. Light the Bunsen burner and adjust it until you get a blue flame.<br />
3. Clean the nichrome wire by dipping it into the hydrochloric acid and then holding the<br />
wire in the flame until the wire adds no colour to the flame.<br />
4. Pick up a small amount of solid sodium nitrate with the wire loop. Hold the end of the<br />
wire in the flame. Record your observations.<br />
5. Clean the wire as in step 3.<br />
6. Repeat steps 4 and 5 with the remaining known samples to complete your flame test<br />
key.<br />
Part B: Identifying Metals in Unknown Metallic Compounds<br />
1. Obtain samples of the unknown metallic compounds.<br />
2. <strong>Test</strong> each sample using the steps 3 and 4 from above. Record your observations and<br />
determine the metal in the unknown samples.
Mrs. E. Dharmai<br />
Discussion<br />
1. Sodium chloride was tested in this lab and produced a specific flame test colour.<br />
a) Describe the colour.<br />
b) Predict the flame test colour if you had tested sodium nitrate. Explain.<br />
2. Why do the compounds have to be heated in the flame first before the coloured light is<br />
emitted?<br />
3. This lab tested several salt compounds that contained a metal and a non‐metal. Is it the<br />
metal or the non‐metal that was responsible for the colour that was produced in the<br />
flame test? Explain.<br />
4. Fireworks come in a variety of beautiful colours. What can you conclude about the<br />
composition of a firework if it displays a red colour upon lighting?
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