Chem 101L-Exp.8
How does the Hydrogen lamp produce light? How is this relevant to the purpose of this experiment? What color is the Hydrogen lamp to the naked eye? What appears when observed through a spectroscope?
Electrical discharge tube-glass tube that contains metal electrodes at each end and is filled with a low-pressure gas, such as hydrogen, helium, or mercury. A stream of fast moving electrons shoots through the gas from the cathode. These electrons get excited to a new energy level and then return to their ground state resulting in the emission of light.
How are the terms in the Rydberg equation defined? How can they be used to determine the starting and/or ending energy levels of an electronic transition?
Rydberg= Change in E = RH(2.18x10^-18)((1/nf^2)-1/ni^2)) For hydrogen nf=2
What instrument requires calibration in this experiment? How is it the same or different than the calibration done in Experiments 6 and 7?
The spectroscope needs calibration form the fluorescent light, we make a calibration curve to calculate wavelength. It's different because it's giving us a new value.
Describe the Balmer series and how to recognize it through experimental observations.
The visible spectrum of light from hydrogen displays four wavelengths, 410 nm, 434 nm, 486 nm, and 656 nm, that correspond to emissions of photons by electrons in excited states transitioning to the quantum level described by the principal quantum number n equals 2.[1] There are also a number of ultraviolet Balmer lines with wavelengths shorter than 400 nm.
How can the components of a mixture be identified using a flame test? What observations assist in drawing conclusions about the components of the mixture? What observations are most helpful? Accurate? Can you identify the relative quantities of each component, or are you only able to identify presence or absence?
The wavelengths that correlate with the energy states can be used along with the color you observe with your naked eye. You cannot identify the quantities due to the lack of information, but you can identify whether it is present or not.
How the energy level of an electron related to the energy of a photon?
They are limited by orbitals.They need a specific amount of energy to jump form one orbital to the next.
How is the spectroscopy done in Experiment 8 different from the measurements made in Experiment 7. In each experiment, what property of light is measured? What property of the molecule is associated with that property of the light?
This experiment is measuring the wavelength of light where as experiment 7 is measuring the absorption of light. The energy level of the molecule is associated with wavelength while the concentration of ion is associated with absorbency.
What samples were used for observations of flame emission spectra? What property of these materials made them appropriate for this experiment? What property of these materials was observed with the naked eye? What was observed with the spectroscope? Are they the same or different? Why?
candle->was observed with spectroscope while salts where observed by the eye and spectroscope. The different salts produced different energies and different wavelengths.
Understand the construction and use of a spectroscope. How does the spectroscope convert the light from a particular source into a spectrum, set of bright lines, or both? Why do different light sources produce different spectra?
diffraction device used to see the different types of wavelengths transmitted
Describe the electronic processes associated with absorption or emission of radiation. Which process is associated with an electron moving to a higher energy level?
gain energy by absorbing light to jump to antoher elvel.
