Question

How many NMR signals does $C{H}_{3}C{H}_{2}OC{H}_{2}C{H}_3$ show ?

Answer 1

The H NMR spectrum of diethyl ether shows two signals.
$H-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-O-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-H$
The molecule has a plane of symmetry, so the two $C{H}_3$ groups are equivalent, and the two $C{H}_2$ groups are equivalent.

We should see two signals with area ratios $6:4$ or $3:2$.

The electronegative $O$ atom pulls all signals downfield. The effect decreases rapidly with distance.

We should expect the $C{H}_2$ groups to be pulled about $2$ ppm downfield from their normal value of $\delta 1.4$. They should give a $4H$ signal at about $\delta 3.4$

We should expect the $C{H}_3$ groups to be pulled about $0.3$ ppm downfield from their normal value of $\delta 0.9$ They should give a 6H signal at about $\delta 1.2$

The signals will be split by spin-spin coupling.

Here is a spectrum of diethyl ether.