You discover a chemical reaction that produces 2 moles of valuable propane for every 8 moles of carbon supplied. essentially, this is an exchange rate of 2 moles of propane for every 8 moles of carbon. if you have 1.7 moles of carbon, how many moles of propane can you produce using this reaction?

Here we have to get the amount of propane can be produced from the reaction of 1.7 moles of carbon (C).

1.7 moles of carbon will produce 0.425 moles of propane

In the reaction 8 moles of carbon is producing 2 moles of propane. Thus, mathematically,

8C  → 2C₃H₈

Thus 8 moles of carbon produces 2 moles of propane

1.7 moles of carbon produces ×1.7 = 0.425 moles

Thus 1.7 moles of carbon will produce 0.425 moles of propane.

Thus the amount of propane will be prepared from the reaction of 1.7 moles of carbon is determined.

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.