Spectrometry: Analyzing Gas Spectra and Spectrometer Operation
Spectrometry
Objectives:
- To study the spectrum of gases and operation of the spectrometer.
- Use the rotary torque sensor to measure the displacement of the disc that circulates graduate degrees and the light sensor to determine position.
- Calculate the intensity of different spectral lines and the mercury lamp or gas used in the broadcast.
- Use the data to study, register, and display data in a graph.
- Determine a pair of him, the angular variation, and with these data to determine the wavelength for each line.
- Use ADO for the commutator bars.
- Determine for each sampling the initial angle, the initial angle, and angular variation.
- Transfer the results to a table in the laboratory report.
Order, Diffraction Angle, Color, Wavelength (nm)
| Order | Diffraction Angle | Color | Wavelength (nm) |
|---|---|---|---|
| 1 | 16.45 | Violet | 470 |
| 1 | 19.72 | Green | 560 |
| 1 | 21.89 | Orange | 618 |
| 2 | 33.03 | Violet | 452 |
| 2 | 43.26 | Green | 568 |
| 2 | 45.97 | Orange | 596 |
Calculation of d
d = (1 / 600) / 1000
Data Collection Using a Spectrometer
This instrument is a device that allows viewers to study gas emissions. The gas, when excited to higher energy levels due to electrical discharges, emits radiation in the form of electromagnetic spectral lines, part of which corresponds to the visible spectrum band. These pass through the slit of the spectrometer and reach the grating.
Procedure:
To locate different spectral emission lines of gas, record the angle at which they are, their color, and the diffraction order.
Order, Diffraction Angle, Color, Wavelength (nm)
| Order | Diffraction Angle | Color | Wavelength (nm) |
|---|---|---|---|
| 1 | 14° | Violet | 403 |
| 1 | 15.5° | Blue | 445 |
| 1 | 17.5° | Green | 501 |
| 1 | 19.5° | Yellow | 556 |
| 1 | 20.5° | Orange | 584 |
| 2 | 29.5° | Violet | 410 |
| 2 | 32.5° | Blue | 448 |
| 2 | 37° | Green | 502 |
| 2 | 42.5° | Yellow | 563 |
| 2 | 45.5° | Orange | 594 |
Questions:
What do you mean by quantization of energy?
It refers to certain discrete amounts of energy that microscopic systems can possess.
Quantization of energy occurs when atoms or particles, like electrons, absorb or emit energy at lower levels, increasing their energetic state. Thus, atoms absorb energy to reach a level where their period increases and emit energy when they descend to a lower level.
How many diffraction orders did you observe?
We managed to see 2 orders of diffraction.
Where should the spectral lines of higher order m be located?
In the experiment, we observed that spectral lines of gas were to turn the eyepiece to the right; therefore, the higher-order spectral lines should be seen at more angles than we saw, that is, turning the spectrometer eyepiece further to the right. ? = 45°
What happens in the center of observing, that is, when ? = 0?
We appreciate the full spectrum of light; as assumed, solely white light was observed, i.e., the central maximum.
What is the electromagnetic energy for each wavelength observed?
Electromagnetic energy flows to every wavelength related to the gas emitted. It is called spectral lines of gas or emission spectrum and can be quantified according to:
?Ei = h ? i where h = Planck’s constant = 6.62 * 10-34 (J * S).
violeta1 = 4.22 * 10-17 J
Verde1 = 3.54 * 10-17 J
Naranjo1 = 3.21 * 10-17 J
Violeta2 = 4.39 * 10-17 J
Verde2 = 3.49 * 10-17 J
Naranjo2 = 3.33 * 10-17 J
The emission spectrum of a gas is the fingerprint of a gas when excited, resulting in different wavelengths.