Flame Test Essay
Lab 1: Flame Test
11 Chemistry, university Preparation Conducted: September 20th, 2010
Purpose:
To observe, and create a chart of the colours produced when solutions of known metal compounds are heated to high temperature.
Question:
What colours are produced when different metallic compounds are placed in a flame, and why this happens?
Hypothesis/Prediction:
Different salts will produce different colours when placed in a flame, due to the fact that each element has a different atomic structure. The electrons will jump to higher energy levels according to the amount of energy absorbed.
Pre Lab Questions:
1. Red is the colour with the lowest energy
2. Violet is the colour with the highest energy
3. Violet is the colour
with the highest frequency
4. Red is the colour with the lowest frequency
5. Electrons are excited when they are given energy. Energy can come from different sources, such as heat or electricity.
6. Electrons are excited when the energy level of an atom or molecule is increased. Energy is increased by heat or electricity; this causes electrons to jump to higher energy levels. The energy that is not absorbed is released; in this case, photons are released, which are packages of energy.
Experimental Design:
- The Nichrome wire should be cleaned with hydrochloric acid prior to each flame test.
- Ensure that, after cleaning the nichrome wire, it should not produce any colour when placed in the flame by itself.
Materials:
- Apron
- Eye Protection
- Nichrome test wire
- 2 test tubes
- Test tube rack
- Cobalt glass squares
- Laboratory burner
- Hydrochloric acid, dilute, 5mL
- Sodium Chloride solution, 3mL
Samples of the following solids:
- Sodium Chloride
- Sodium Nitrate
- Calcium Chloride
- Strontium Chloride
- Lithium Chloride
- Potassium Chloride
- Copper II Chloride
Procedure:
1. Obtain your samples (the solids and 3mL of the sodium chloride solution in a small test tube) and the 5-mL hydrochloric acid solution (also in a small test tube). Store the test tubes in a rack.
2. Light the laboratory burner and adjust it until it is burning with a blue flame.
3. To clean the Nichrome test wire, dip it in hydrochloric acid and then hold the wire in the flame of the laboratory burner. Repeat the procedure until the wire adds no colour to the flame.
4. Pick up a small amount 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. Pick up a small sample of solid sodium chloride on the wire end, hold the end of the wire in the flame for several seconds. Record your observations.
7. Clean the wire as in step 3.
8. Repeat step 4 with each of the solid samples, remembering to clean the wire after each test. Record your observations.
9. Repeat the flame test for Potassium Chloride and Sodium Chloride, observing their results through cobalt glass. Record your results.
Observations:
SOLIDS OBSERVATIONS
Sodium Chloride -Very Orange
Sodium Nitrate -Very Red
Calcium Chloride -Orangy-Red
Strontium Chloride -Very Red/orange
Lithium Chloride -Red
Potassium Chloride -Pale Yellow
Copper II Chloride -Green, Blue
Analysis:
Based on the observations, we have learned that there are energy levels present in atoms and ions. When electrons are in the lowest possible energy levels, they are in the “ground state”. The reason coloured light is emitted is because the electrons of atoms jump to higher levels of energy when given an energy source, which, in this case, was the flame. When this happens, the electrons are said to be in an “excited state”. With regard to the arrangement of electrons in an atom, the size of the quantum jump can be determined. This enables us to further determine the energy and colours of the photons emitted. It is clear that when the wavelength is long, the energy is less; and vice versa, short wavelengths mean higher energies.
The picture above shows that the colour red has higher wavelength, and shorter frequency.
Therefore when an atom/molecule emits a blue-green colour, such as Copper II Chloride, we know that the electrons jumped to high energy levels. The electron gives off photons with relatively short wavelengths. However, the red colour emitted by Lithium Chloride tells us that the electrons did not rise to levels as high as Copper II Chloride.
Synthesis:
1. The cobalt glass acted as a filter during this experiment. It was used when observing the colour of light emitted by potassium chloride and sodium chloride. The main purpose is to remove or filter out the yellow flame caused by the presence of sodium. This enables us to clearly see the violet and blue light.
2. (pg.44) According to my observations, image 1-Calcium Chloride, image 2- Copper II Chloride, image 3- Potassium Chloride, image 4- Lithium Chloride
11 Chemistry, university Preparation Conducted: September 20th, 2010
Purpose:
To observe, and create a chart of the colours produced when solutions of known metal compounds are heated to high temperature.
Question:
What colours are produced when different metallic compounds are placed in a flame, and why this happens?
Hypothesis/Prediction:
Different salts will produce different colours when placed in a flame, due to the fact that each element has a different atomic structure. The electrons will jump to higher energy levels according to the amount of energy absorbed.
Pre Lab Questions:
1. Red is the colour with the lowest energy
2. Violet is the colour with the highest energy
3. Violet is the colour
with the highest frequency
4. Red is the colour with the lowest frequency
5. Electrons are excited when they are given energy. Energy can come from different sources, such as heat or electricity.
6. Electrons are excited when the energy level of an atom or molecule is increased. Energy is increased by heat or electricity; this causes electrons to jump to higher energy levels. The energy that is not absorbed is released; in this case, photons are released, which are packages of energy.
Experimental Design:
- The Nichrome wire should be cleaned with hydrochloric acid prior to each flame test.
- Ensure that, after cleaning the nichrome wire, it should not produce any colour when placed in the flame by itself.
Materials:
- Apron
- Eye Protection
- Nichrome test wire
- 2 test tubes
- Test tube rack
- Cobalt glass squares
- Laboratory burner
- Hydrochloric acid, dilute, 5mL
- Sodium Chloride solution, 3mL
Samples of the following solids:
- Sodium Chloride
- Sodium Nitrate
- Calcium Chloride
- Strontium Chloride
- Lithium Chloride
- Potassium Chloride
- Copper II Chloride
Procedure:
1. Obtain your samples (the solids and 3mL of the sodium chloride solution in a small test tube) and the 5-mL hydrochloric acid solution (also in a small test tube). Store the test tubes in a rack.
2. Light the laboratory burner and adjust it until it is burning with a blue flame.
3. To clean the Nichrome test wire, dip it in hydrochloric acid and then hold the wire in the flame of the laboratory burner. Repeat the procedure until the wire adds no colour to the flame.
4. Pick up a small amount 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. Pick up a small sample of solid sodium chloride on the wire end, hold the end of the wire in the flame for several seconds. Record your observations.
7. Clean the wire as in step 3.
8. Repeat step 4 with each of the solid samples, remembering to clean the wire after each test. Record your observations.
9. Repeat the flame test for Potassium Chloride and Sodium Chloride, observing their results through cobalt glass. Record your results.
Observations:
SOLIDS OBSERVATIONS
Sodium Chloride -Very Orange
Sodium Nitrate -Very Red
Calcium Chloride -Orangy-Red
Strontium Chloride -Very Red/orange
Lithium Chloride -Red
Potassium Chloride -Pale Yellow
Copper II Chloride -Green, Blue
Analysis:
Based on the observations, we have learned that there are energy levels present in atoms and ions. When electrons are in the lowest possible energy levels, they are in the “ground state”. The reason coloured light is emitted is because the electrons of atoms jump to higher levels of energy when given an energy source, which, in this case, was the flame. When this happens, the electrons are said to be in an “excited state”. With regard to the arrangement of electrons in an atom, the size of the quantum jump can be determined. This enables us to further determine the energy and colours of the photons emitted. It is clear that when the wavelength is long, the energy is less; and vice versa, short wavelengths mean higher energies.
The picture above shows that the colour red has higher wavelength, and shorter frequency.
Therefore when an atom/molecule emits a blue-green colour, such as Copper II Chloride, we know that the electrons jumped to high energy levels. The electron gives off photons with relatively short wavelengths. However, the red colour emitted by Lithium Chloride tells us that the electrons did not rise to levels as high as Copper II Chloride.
Synthesis:
1. The cobalt glass acted as a filter during this experiment. It was used when observing the colour of light emitted by potassium chloride and sodium chloride. The main purpose is to remove or filter out the yellow flame caused by the presence of sodium. This enables us to clearly see the violet and blue light.
2. (pg.44) According to my observations, image 1-Calcium Chloride, image 2- Copper II Chloride, image 3- Potassium Chloride, image 4- Lithium Chloride