Chapter 14 Flashcards Preview

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Flashcards in Chapter 14 Deck (17):
1

P value between 0.1 - 1.0

high intensity. greater molar absorptivity

2

P value less than 0.1

low intensity. lower molar absorptivity

3

gas has less/more fine structure in wavelength vs abs.? why?

more. greater freedom of rotation/vibration

4

ppm

mg/L

5

molar absorptivity =

PA(8.7*10^19) where P is probability, and A is molecule cross section

6

molar absorptivity range

1-10^-5

7

electronic excitation lifetime in UV-vis

10^-8 sec

8

which has more fine structure in wavelength vs abs., organic nonpolar or polar?

organic nonpolar

9

Why are all organic compounds capable of absorption?

valence electrons can be excited

10

single bonds absorb in ? region

vacuum (<185)

11

heteroatoms absorb in ? region

UV

12

first two rows of transition series absorb in ? region

visible

13

charge transfer absorption

electron donor bound to electron acceptor absorbs light. excited electron is transferred to acceptor.

14

charge transfer absorption results in?

high molar absorptivity and sensitivity, highly olored compounds

15

auxochromes

cause red shifts. OH and NH2. changes absorbance of parent molecule, but don't absorb UV. stabilize pi*

16

why choose UV-vis

1) easy; available and straightforward 2) low detection limit 3) selective 4) accurate

17

method of continuous variation

vary ligand to metal ratio. peak in absorbance occurs when ratio matches that of ML with maximum bonds