Please show work and explain: The reaction A + B → C is studied similarly to our study of phenolphthalein fading kinetics.

The corresponding rate law is Rate = k[A]m[B]m

In this particular experiment, the concentration of A is sufficiently high that the pseudo-order rate law: Rate = k1[B]n can be written, where k1 = k[A]m.

If the study establishes that the reaction is first order in B (n = 1) and that the pseudo rate constant k1 has the following values at varying concentrations of B, what is the order of the reaction in reactant A (what is the value of m)?

k1[B]
0.00340.200 M
0.00200.100 M
0.00100.050 M
Options:

A.0
B.1
C. 2
D.3

Explanation:

Consider the given reaction,

A+B +C

Reaction is first order with respect to reactant B.

The pseudo order rate is

Pseudo order reaction is the reaction in which the reactant concentration remains constant; its concentration is very high so it does not involve in the rate of the reaction. Here, the concentration of  A is sufficiently high so this reaction becomes the pseudo first order reaction.

The reaction is first order with respect to [B] with rate constant k1 .

Using the given table, concentration of  B is decreasing the rate also decreasing

Therefore, order of the reaction with respect to A  is 1.

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.