AC2 Task answers

Task 2.2.1

Here are the answers to the functional groups. The ether group (first molecule in the second row) snuck in, we don't need to do it. There's another one, unlabelled, down the bottom (last molecule), ignore it too.

TASK 2.2.3

QUIZ 2.2.1

1. A Note the broad OH peak (= alcohol) around 3300 cm-1 and alkene (-en = alkene) peaks around 3000 cm-1and (more weakly) 1650 cm-1.

2. D The peaks relating to the alcohol (-OH) will be gone and the new alkene peaks will have appeared (3000-3100 cm-1 and 1550-1650 cm-1).

3. B Notice the peaks around 3100-3500 cm-1 which are typical of an amine. The primary amine will have two peaks (two N-H bonds).

TASK 2.2.4

QUIZ 2.2.2

1. D 84: If you add up the masses of C x5 + H x8 + O x1 = 84.

2. Q2 not relevant

3. D methanol: CH4O has a molecular weight of 32. (Note the very small peak at 33 is likely due to the 13C isotope of carbon).

QUIZ 2.2.3

Sucrose

– Look for an alcohol peak.

– All carbons in sucrose are attached to an oxygen, i.e., there are no carbons attached only to other carbons. (Peaks must all be above approx. 50 ppm)

Aspirin (acetylsalicylic acid)

– The peak numbers match the number of carbons (the carbons in this molecule lack equivalence).

– There are carboxylic acid and ester peaks.

– All the carbons are either directly attached to an oxygen (carboxylic acid and ester) or are part of the aromatic ring…except one (which you would expect to be under 50 ppm).

Methamphetamine

– Look for a C-N carbon.

– Look for alkane peaks.

– There are 8 peaks, but 2 are twice the height (which generally implies there are 2 carbons for each of those peaks), indicating 10 carbons.

QUIZ 2.2.4

1. A The 2 carbon peaks are non-equivalent because they are in different local chemical environments, 1 shifted just below 60 ppm due to its bonding to oxygen.

2. B While there are 4 carbons in butane, the 2 middle ones are equivalent and the 2 outer ones are equivalent, ultimately giving 2 peaks.

3. C We’d expect 4 peaks (4 non-equivalent carbons) – 1 in the carboxylic acid region (around 180 ppm) and 3 below 50 ppm (alkyl group carbons such as C-CH2-C and –CH3)

TASK 2.2.5

Bottle 1 hexa-1,5-diene

Bottle 2 3-hydroxybutanone

Bottle 3 1,4-dioxane

Bottle 4 1,3-dioxane

QUIZ 2.2.5

ethyl ethanoate

Google Sites

Report abuse