4. When plotting a standard curve in absorption spectrophotometry, one uses Abs values instead of %T values. Explain why you need to use Abs values instead of %T values when constructing a standard curve (or a linear Beer's law Plot)

6 why it makes sense to use an internal standard in IR spectrometry when its not used in Uv-Vis

Match the wavelength range of electromagnetic radiation to the type of spectroscopy. > 4000-600 cm-1 10 - 380 nm 380-780 nm 1. IR Spectroscopy 2. Ultra Violet Spectroscopy 3. Visible Spectroscopy

None

6-what is difference between Transmittance and absorbance in spectroscopy?

d) Doppler broadening is a source of line broadening in the flame of an atomic absorption instrument, λ = 20 (7x10-7)(0.5. Find the Doppler line width for the absorption line λ = 248.3 nm of Fe in a 2500 K flame (T), where M is the mass of the atom (56 Da).

Which of the the following is false regarding spectrophotometry?   A. The concentration of a sample increaes with the path length of the curvette or sample holder since the absorbance increases   B. When absorbance increases, transmittance decreases   C. The absorption coefficient depends on wavelength of light and type of sample   D. Materials with higher absorption coefficients more readily absorb light.   E. The lambda max of a red sample is at a shorter wavelength than the lambda max of a blue sample

Absorbance measurements in the range of A = 0.3 - 2 are considered the most accurate. Why are absorbance measurements of 0.05 and 2.5 considered inaccurate? If the absorbance is too high (A = 2.5), the signal difference between the sample and the reference is too small for an accurate measurement. At A = 2.5, the transmission is too high for an accurate measurement. The difference in the absorbance of the sample and reference is too small at A = 0.05. At A = 2.5, the detector is saturated because too much light is reaching the detector. At A = 2.5, a sufficient amount of light does not reach the detector for an accurate measurement.

The Beer’s Law plot of the standard curve for the equilibrium experiment was determined by plotting?   absorbance versus [Fe3+]   absorbance versus % transmittance   % transmittance versus [FeSCN2+]   absorbance versus [FeSCN2+]

18