## G.25

Gabriella Bates 2L
Posts: 95
Joined: Thu Jul 11, 2019 12:15 am

### G.25

"Practitioners of the branch of alternative medicine known as homeopathy claim that very dilute solutions of substances can have an effect. Is the claim plausible? To explore this question, suppose that you prepare a solution of a supposedly active substance, X, with a molar concentration of 0.10 mol?L21. Then you dilute 10. mL of that solution by doubling the volume, doubling it again, and so on, for 90 doublings in all. How many molecules of X will be present in 10. mL of the final solution? Comment on the possible health benefits of the solution."

I am somewhat confused on how to solve this problem. I looked at the solution manual and I understand the math involved in the solution, but is there more simple was to solve/conceptualize it? Also, would something like this appear on an exam? Thank you

sbeall_1C
Posts: 91
Joined: Sat Sep 07, 2019 12:17 am
Been upvoted: 1 time

### Re: G.25

For this problem, I think it is important to remember the key concept from the book and the lecture that the moles of solute remain the same when diluting a solution, but that the concentration changes. You start with 10 mL of substance X with a set concentration. You then double and continue to double the volume, which reduces the concentration of substance X to nothing, so that when you remove the 10 mL sample after the 90 doublings of volume, the concentration of substance X is 0, and there can be no health benefits.