repete86 
Quote:
Originally Posted by repete86
You would need 20000 of those pills to get 100 ml's of pure selenium. Doesn't sound very cost effective.

(EDIT : repete86, I see where you got the 100 ml now, I thought you just used the number as an example. The 100 ml is the amount of 87 octane gasoline. The question I am trying to answer is, what is "1.5 ppm" of selenium needed for a gallon of gas? The pills in the example above have 50 mcg of selenium per pill. I should have used that as the basis for my calculations, not the 100 ml you site)
(EDIT #2 : The numbers below can't be right because the this is a difference between liquids and solids, I think
)
(EDIT #3 : Ignore this post!!!!!!!!!!!!!!)
At 1.5 ppm, how many ml's of selenium do you need for one gallon of gas?
From here :
http://www.onlineconversion.com/volume.htm
I get :
100 milliliter = 0.026417205 gallon [US, liquid]
1 part per million = 1 / 1,000,000 = 0.000001 => 1 ppm
Sooooooo, => 0.026417205 gallon / 0.000001 = 26417.205 ppm
But, we only need 1.5 ppm, so let's solve as follows :
20000 pills will yield 26417.205 ppm
X pills will yield 1.5 ppm
The above are
equivalent ratios, so I can solve for X as follows :
20000 / 26417.205 = X / 1.5 => X = ( 20000 / 26417.205) * 1.5 = 1.1356 => about 1.2 pills per gallon of gas.
Sooo, at $2 for 100 pills, the cost per pill is $.02 per pill.
Therefore, assuming all the numbers above are correct, the price per gallon where 1.2 pills per gallon are needed would be less than $.03 per gallon.
Can someone check my numbers?
CarloSW2