A32.00 ml sample of an unknown h3po4 solution is titrated with a 0.110 m naoh solution. the equivalence point is reached when 24.83 ml of naoh solution is added. what is the concentration of the unknown h3po4 solution? the neutralization reaction is
h3po4(aq)+3naoh(aq)→3h2o(l)+na3po4( aq)

Concentration of in sample is 0.25 M.

Explanation:

From the reaction, one mole of reacts with 3 moles of NaOH.

Now, number of moles of NaOH, n =

Therefore, mol of NaOH reacts with .

So, concentration of

Therefore, concentration of in sample is 0.25 M.

Hence, this is the required solution.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

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.