Question

How many NMR signals does `CH_3CH_2OCH_2CH_3` show?

Answer 1

The H NMR spectrum of diethyl ether shows two signals.

The molecule has a plane of symmetry, so the two CH₃ groups are equivalent, and the two CH₂ 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 CH₂ groups to be pulled about 2 ppm downfield from their normal value of δ 1.4. They should give a 4H signal at about δ 3.4.

We should expect the CH₃ groups to be pulled about 0.3 ppm downfield from their normal value of δ 0.9. They should give a 6H signal at about δ 1.2.

The signals will be split by spin-spin coupling.

Here is a spectrum of diethyl ether.