from revision 2

Question 1

lyman series

Answer 1

n = 1
uv radiation

alpha transition = 2 -> 1
series limit = infinity -> 1

Question 2

balmer series

Answer 2

n = 2
visible radiation

alpha transition = 3 -> 2
series limit = infinity -> 2

Question 3

paschen series

Answer 3

n = 3
infrared radiation

alpha transition = 4 -> 3
series limit = infinity -> 3

Question 4

rhydberg equation and what it does

Answer 4

wn = RH x (1/n2 - 1/n2)

gives wavenumber of the transition from n to n

first n is the smaller number
2nd n is the larger number
final - initial basically

Question 5

what is the rhydberg constant

Answer 5

1.097 x 10^5 cm-1

Question 6

what is seen in uv vis spec

Answer 6

things moving between molecular orbitals

aka sigma star, sigma, pi, pi star etccc.

can transition to 2 levels

Question 7

isobestic point in uv vis spec

Answer 7

molecule goes from one state to another with no intermediate

Question 8

what spec is IR spec

Answer 8

vibrational spec

causes stretching and bending in molecules

only when the molecule has a changing dipole tho :specific selection rule

Question 9

IR spec and harmonic oscillator

Answer 9

shows how the potential energy changes from the spring being compressed, to relaxed, to stretched.

opposite to the ke

pe = U
ke = n

Question 10

vibrational energy in ir spec is

Answer 10

quantised

energy at level 0 = 1/2hw

Question 11

harmonic oscilator ir spec energy level equation

Answer 11

energy at V: hw(V+1/2)

Question 12

energy difference between 2 energy levels on a harmonic oscillator ir spec vibrational spec

Answer 12

hw

Question 13

what is w harmonic oscillator, vib spec, ir spec

Answer 13

fundamental frequency s-1

V = vib level quantum number

h = plancks constant

Question 14

what is k in harmonic oscillator, via spec, ir spec

Answer 14

force constant nm-1
same units as wavenumber

larger spring constant means larger w

stiffness of spring

Question 15

what is the fundamental frequency in vib spec, ir spec tho

Answer 15

the frequency needed to transition between energy levels on harmonic oscillator

Question 16

finding w, vib spec, ir spec equation

Answer 16

w = 1/2pi x root (k/rm)

k = force constant
rm = reduced mass ( /1000 /avo)

m1 x m2 / m1 + m2

Question 17

selection rules for vib spec, ir spec

Answer 17

gross selection rule: can only interact with ir if theres a changing dipole

specific selection rule: change in V can only be 1. eg can only transition 1 energy level higher. hw difference between the 2 energy levels.