Energy
The larger the wave length, the ______ the frequency.
What range of light (in nm) do chromophores absorb?
What is 400-700 nm, the visible range?
The following image is of which kind of instrument?
What is an atomic absorption spectrometer (AAS)?
According to a Jablonski, which happens the fastest absorption, fluorescence, or phosphorescence?
What is excitation?
For acquiring concentration from a sample, which method is more robust, Beer's Law or generating a calibration curve?
What is generating a calibration curve?
Using E=hv, what is the energy of a photon with a frequency of 0.000427 s-1?
What is 2.83 x 10-37 J/photon?
Name one limitation to Beer's Law that we discussed in class.
What are any of the following?
Only useful for analyte absorbing at a unique wavelength, only works in dilute solutions, or absorbance needs to be measured at the maximum wavelength.
In a double beam spectrophotometer, this allows the sample and blank to be measured at the same time.
What is the beam splitter.
What is the analytical term of the ratio of photons emitted to photons excited?
What is Quantum Yield?
Can you use a calibration curve if your unknown is beyond the highest standard of the curve?
What is No?
What is the relationship of wavenumber to wave length?
What is inverse or 1/wavelength?
In Atomic Absorption Spectroscopy (AAS), how are the bands different from molecular absorbance? Why?
What is AAS has narrower bands due to lack of rotational and vibrational levels?
What are the two types of wavelength selectors in fluorometers?
What are excitation and emission wavelengths?
What was the 2008 Nobel prize of chemistry awarded for?
What is Green Fluorescent Protein (GFP)?
In an internal standard calibration curve, what is the label of the Y axis and what characterizes the ratio?
What are Signal Ratio and analyte signal to internal standard signal?
Given an energy of 83.6 x 10-8 J/mol, determine the wavenumber.
What is 6.99 x 10-6 m-1?
A spectrophotometer measured a 1 cm cuvette to have an absorbance of 0.632. The molar absorptivity of the analyte in the sample was 13,420 M-1 cm-1 . Determine the concentration of a sample in mM.
What is 0.0471 mM?
When looking at a Jablonski, there are three main excited states. This is the excited state for the longest photon emitting state.
What is phosphorescence, T1?
What is the stoke shift of a fluorophore if the excitation was at 475 nm and an emission at 536 nm?
What is 61 nm?
A sample of with an unknown concentration of analyte (initially 3.9 uL) was diluted to 12.0 uL then measured in a spectrophotometer for an absorbance of 2.031. An external calibration curve was generated with a slope of y = 1.043x + 0.022. What was the initial concentration of the analyte?
What is 5.9 mM?
If the energy of a solution is 17.854 kJ/mol, what is its wavelength(express your answer in mm with 3 significant figures)?
What is 6.70 mm?
A spectrophotometer measure a sample's incident power of light (Po) as 3.945 and the power of the sample (P) as 1.522. What is the percent transmittance and absorbance?
What are T= 38.58% and A = 0.4136?
A single beam spectrophotometer is only useful in which ranges of light relative to the electromagnetic spectrum?
What are the UV and visible ranges?
Which pair is most likely to perform FRET?
Fluorophore Excitation Emission
DAPI 358 461
GFP 488 507
Cy3 550 570
mCherry 587 610
What are Cy3 and mCherry?
A chemist uses an internal standard to determine the concentration of an unknown analyte using a spectrometer. An analyte was diluted ten-fold then used to generate a calibration curve with mM on the x-axis. The calibration curve has a slope of y = 0.534x +0.032. The unknown has an analyte signal of 340 and a standard signal of 250. What is the concentration in mM of analyte?
What is 24.9 mM?