how do you calculate empirical formula?

How do you obtain the molecular formula?

Alternative method to calculate molecular formula

How do you find the number of double bond equivalents?

1 DBE

2 DBE

4 DBE special case

Beer-Lambert Law

IR
600-1400 cm-1

IR
1600- 1850 cm-1

IR
2100-2300 cm-1

IR
2700-3000 cm-1

IR
3000-3200 cm-1

IR
3200-3450 cm-1

H NMR
δ7-δ8

H NMR
δ5-δ6

H NMR
δ2.5

H NMR
δ9-δ10

H NMR
δ10+

H NMR
~δ1-2

H NMR
~δ2.5

C NMR
δ165-210

C NMR
δ100-150

C NMR
δ65-90

C NMR
δ0-40

C NMR
δ75-95

C NMR
δ110-150

C NMR
δ30-65

H NMR
Withdrawing groups next to the proton

H NMR
Donating groups next to H

If resonance can occur such as a double bond near a carbonyl it is often the H nearest to the opposite end of the carbonyl that is more deshielded rather than the H nearest the withdrawing O because of the resonance sturucture. The same can be said for the Hs near donating groups. See pics

Three factors that affect J (coupling constant)

roofing

1H NMR exchange

13C NMR
Electronegative substituents

Intensity of signals in 13C NMR

13C-13C coupling

13C-1H coupling

13C-1H off resonance coupling