PLEASE HELP! 1. Describe the relationship between the mole and molar mass.
2. describe the process for converting between moles and molar mass.
3. Explain how percent composition is calculated and why is it important in the determination of empirical formula.
4. Analyze the role coefficients in a chemical reaction play in stoichiometry
Explain what a limiting reactant is and describe the process to determine the limiting reactant in the example listed below:
5. Given 3.4 grams of x element with a molar mass of 24 g/mol and 4.2 grams of y element with a molar mass of 35 g/mol. How much of compound xy2 can be generated?
x + 2y -> xy2
6. Explain where you would find the actual yield and the theoretical yield needed to calculate the percent yield of a reaction. Is the answer listed above the theoretical or actual yield?

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.

it is a solid

explanation: