N+1 Splitting Rule
Each proton type “senses” the number of equivalent proton(s) (let us call this number, n) present on the carbon atoms which are next to it. In response, its resonance peak, instead of showing one peak, is split into (n+1) components
Coupling constants
Coupling constants of protons which cause splitting of each others resonance peaks, have the same value.
Spin-spin splitting- usually only caused by protons which are located next to each other
Integrals- These can be used to give relative numbers of each type of hydrogen present. As long as there is more than one peak present, ratios of the integral heights of the peaks can be used to determine the number of protons which give rise to each peak.
To do this: First the heights of the integrals are measured. The larger values are divided by the smallest value to obtain simple ratios. The true ratios must be found via multiplication of the simple ratio. For e.g. if a 1.5:1.0 ratio is found for the simple formula, clearly you can’t have 1.5 protons. These values must be multiplied by 2 to obtain the true ratio of 3:2 protons
Multiplet Skewing – The peaks present for multiplets are usually of different heights. An arrow can sometimes be drawn from the peak of the smallest height to that of the largest height, which indicates the the direction of the peaks which correspond to a proton or maybe the groups of protons which causes the splitting. So this therefore, gives you clues as to the location of peaks which belong to protons/groups of protons that are adjacent to the proton/groups of protons that are represented by the multiplet.
Extra Tip:The ethyl groups multiplet peaks have height ratios of 1:3:3:1 while resonance peaks for methyl groups have a height ratio of 1:2:1
