How many moles are present in 1.75 moles of dihydrogen monoxide, h2o?

31.5 grams

Explanation:

I'm guessing you meant how many grams are in 1.75 moles of H2O

You need a periodic table for this first you're going to find the atomic mass for Hydrogen (1.008) and oxygen (15.999)

since there are 2 Hydrogen in the problem you'll multiply 1.008 by 2 giving you 2.016

You'll then add your 1 Nitrogen to this to get 18.015: this number is the grams for 1 mole of H2O, you'll then multiply 18.015 by 1.75 to find the grams for that many moles (31.52625) this is how many grams are in 1.75 moles of H2O

Don't forget sig figs though so your answer will be 31.5

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.