Chapter L3, Problem 12E

For CARS, which statement is not true regarding its advantages? a) Contrast signal based on vibrational characteristics, no need for fluorescent tagging. b) Stronger signals than spontaneous Raman. c) Suffers from fluorescence interference, because CARS signal is at high frequency. d) Faster, more efficient imaging for real-time analysis. e) Higher resolution than spontaneous Raman microscopy.

Draw the major product of the Claisen condensation reaction between two molecules of this ester. Ignore inorganic byproducts. Incorrect, 5 attempts remaining 1. NaOCH3/CH3OH 2. Acidic workup Select to Draw O Incorrect, 5 attempts remaining The total number of carbons in the parent chain is incorrect. Review the reaction conditions including starting materials and/or intermediate structures and recount the number of carbon atoms in the parent chain of your structure. OK

Using a cell of known pathlength b = 1.25115 x 10-3 cm, a water absorption spectrum was measured. The band at 1645 cm-1, assigned to the O-H bending, showed an absorbance, A, of 1.40. a) Assuming that water density is 1.00 g/mL, calculate the water molar concentration c (hint: M= mole/L) b) Calculate the molar absorptivity, a, of the 1645 cm-1 band c) The transmitted light, I, can be written as I= Ioexp(-xb), where x is the absorption coefficient (sometimes designated as alpha), Io is the input light, and b is the cell pathlength. Prove that x= (ln10)*x*c d) Calculate x for the 1645 cm-1 band