What does this mean?

IR can be used for all the following:

Look for peaks in characteristic regions of the graph. The stretching vibrations are the easiest to identify. Here are some of the bonds or functional groups that might be present in your molecule, together with some peaks typical of each:

Alcohol: Strong, broad peak in the 3200 to 3650 range. (Note: all numbers here are wavenumbers.)

Alkanes: Strong narrow peak with two or three bands in the 2850 to 3000 range.

Alkenes: Medium narrow peak in the 3020 to 3100 range, together with a variable-strength peak in the 1630 to 1680 range.

Amines: Weak peak (or two peaks if NH2) in the 3300 to 3500 range.

Aldehydes and Ketones: Strong, sharp peak in the 1690 to 1750 range

Esters: Strong peak in the 1735 to 1750 range; also strong peak with two bands in the 1000 to 1300 range.

Alkynes: Strong sharp peak at about 3300, together with variable-strength peak in the 2100 to 2250 range.

Carboxylic acids: Broad, strong peak in the 2500 to 3300 range, together with strong peak in the 1705 to 1720 range and medium peak in the 1210 to 1320 range.



Read more: How to Identify Functional Groups in an IR Spectrum | eHow.com http://www.ehow.com/how_8185593_identify-functional-groups-ir-spectrum.html#ixzz1sUaPpnp4

One student suggests that infrared spectrum could be used to identify which stucture, 1,2 or 3, is correct for an alkene Y. Explain with reason, whether the student is correct.

I don't get it means by "alkene is correct"

One student suggests that infrared spectrum could be used to identify which stucture, 1,2 or 3, is correct for an alkene Y. Explain with reason, whether the student is correct.

I don't get it means by "alkene is correct"

The question isn't referring to the alkene, it is referring to structures 1, 2 and 3. It is a bit poorly worded, but they're asking you to see whether an IR spectrum could differentiate between the possible structures of the alkene.