IR spectrum

Animal lover :))

Hi, the question says the answer is an alkene I'm wondering if the part I circled shows the c double bond c 1620-1680

Also if this is correct, can a peak be small like that because I always thought a peak had to be large

Reply 3

UtterlyUseless69

Original post by Animal lover :))

Also if this is correct, can a peak be small like that because I always thought a peak had to be large

Alkene peaks usually are pretty tiny (they are usually described as being small to medium). It’s one of their most defining features.

From what I can see, you appear to have circled the right peak.

I suppose you could also say it’s not an alcohol because it doesn’t have the classic, broad alcohol peak from circa 3200 - 3600 cm^-1.

Reply 4

Animal lover :))

Original post by UtterlyUseless69

Alkene peaks usually are pretty tiny (they are usually described as being small to medium). It’s one of their most defining features.
From what I can see, you appear to have circled the right peak.
I suppose you could also say it’s not an alcohol because it doesn’t have the classic, broad alcohol peak from circa 3200 - 3600 cm^-1.

Thank you!

Reply 5

ksmithk

try to use logic. the main two regions you look at are above 3000 for OH groups and between 1500 and 2900m usually for C=O. If there is a peak between 1500 and 2900 then you need to account for it so in this case it MUST be the alkene.