1. grams of spiro in 5% sol

if i want to make a 240ml solution with 5% spiro, how many grams of spiro will be needed? i'm getting approx 12 grams. Does that sound right?

2. 240ml @ 5% = 2.1 (.05/240 ) 1ml=1mg. 1g=1000mg. 2100mg or 2.1g/240ml to make it 5%/240ml spiro.
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3. 5% should read 5g/100ml so for 240ml you have to put 2.4X in your solution to get 5% that means 12g as you said and not 2.1g as Ghosting said.

4. Originally Posted by sir.kevin
5% should read 5g/100ml so for 240ml you have to put 2.4X in your solution to get 5% that means 12g as you said and not 2.1g as Ghosting said.
Doh. I didnt know percentages were based off every 100ml of solution. Thanks for the correction and the info.

5. i was looking over ghosting's post and could follow the last part but just couldn't figure out the where the 2.1 was coming from. when i tried the calc i used 1g or spiro equals 1ml of solution(pg,iso,glycerin). as sir kevin says 5% of 240 would be 12ml or 12g. it should actually be a little less than that since this only holds true for water(1ml of water has a mass of 1g). formula weight is sometime used for concentration calcs. the weight of spiro is 23x that of water. water is 18 and spiro is 416. wouldn't it be possible to say that only 1/23g of spiro=1mlor 1g=23ml. that would be approx 43mg=1ml. at 43*12=516 mg would be necessary to displace 12ml of solution. this is only an idea. does it sound possible?
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6. Basically what you have to do if you want to be precise is to put your powder (12g) in a recipient then complete it up to 240ml (pre-marked) with your solvent. Then you will have exactly 5% solution without any further calculation.

7. Originally Posted by info_cker
i was looking over ghosting's post and could follow the last part but just couldn't figure out the where the 2.1 was coming from.
Even though I was wrong.

Originally Posted by Ghosting
240ml @ 5% = 2.1 (.05/240 )

8. thanks for the info. i mentioned idea about using formula weight because i was researching different ways cacl concentration. for simplicity i will assume that 1g displaces 1ml of volume. that way 12g will give a 5% by volume solution

9. As i said you don't need to do that. Once the spiro disolved in your solution and your recipient completed with the carrier up to marked level, then you will have exactly 5% solution.

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