The data below show the concentration of n2o5 versus time for the following reaction: n2o5(g)→no3(g)+no2(g) time (s) [n2o5] (m) 0 1.000 25 0.822 50 0.677 75 0.557 100 0.458 125 0.377 150 0.310 175 0.255 200 0.210 part a determine the order of the reaction.

First order

Explanation:

Hello,

For this question, the general rate law must be considered:

By linearizing it, one could get:

Whereas n stands for the order of the reaction and k the rate constant. For it, I attached an Excel doc for you to see the linearization, in which the slope matches with n, which has a value of 0.999 (neglecting the both the inital and final data otherwise the result is nearly 0.93), thus one could state that the order of the reaction is: first order.

Note: the differential is found by using the centered differentiation formula (Chapra, numerical analysis).

Best regards.

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.