Label the spin–spin splitting that you would expect to observe in the nmr spectrum of 1-methoxypropane. not all labels will be used. note: if one or more reagents are incorrectly placed, a single red x will appear on the top left.

The structure of 1-methoxypropane is CH₃-CH₂-CH₂-OCH₃

I will label the carbons A-D from left to right.

A      B     C        D
CH₃-CH₂-CH₂-OCH₃

In a proton NMR spectrum, we are looking at the chemical shifts of each unique hydrogen atom, and the splitting patterns tell us how many hydrogens are attached to the adjacent carbon. Therefore, the signal from the protons on carbon A will be split by the protons on carbon B, and the signal for protons on carbon A will have a splitting pattern equal to n+1, where n = number of hydrogens on the adjacent carbon.

Therefore, for the protons on carbon A, there are two neighbouring protons and these will give a splitting patter of 3 peaks, also known as a triplet.

Protons on carbon A: 2 adjacent protons result in a triplet signal.

Protons on carbon B: 5 adjacent protons result in a sextet signal.

Protons on carbon C: 2 adjacent protons result in a triplet signal.

Protons on carbon D: 0 adjacent protons result in a singlet signal.

Answer: abeexplanation:

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

The answer is 323 g.