Based on the activity series provided which reactants will form products? F>Cl>Br>l

CuI₂ + Br₂

Explanation:

1) The activity series F > Cl > Br > I means that F is the most active and I is the least active of those four elements (the halogens, group 17 in the periodic table).

The activity is a measure of how eager is an element to react compared to other elements in the series in a single replacement reaction.

2) Choice 1: CuI₂ + Br₂

Since the activity of Br is higher than that of I, Br will react with CuI₂, displacing I, which will be left alone, as per this chemical equation:

CuI₂ + Br₂ → CuBr₂ + I₂

Being I less active than Br, it cannot displace Br in CuBr₂.

3) Choice 2: Cl₂ + AlF₃

Being Cl less active than F, the former will not displace the latter, and the reaction will not proceed.

4) Choice 3: Br₂ + NaCl

Again, being Br less active than Cl, the former will not displace the latter, and the reaction will not proceed.

5) Choice 4: CuF₂ + I₂

Once more, being I less active than F, the former will not displace the latter, and the reaction will not proceed.

hope this helped!

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.

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.