# Allegation Medial

by Sandy
(Raleigh)

Example problem in the book:

Prepare 1/2 L solution of 70% alcohol from 50% alcohol and 95% alcohol

500ml x .7 = 350g

Here is the part I don't understand:

278 ml x 0.5 = 139g
222 ml x 0.95 = 211g
139 g + 211 g = 350g

I thought it would be:

15/35 x 350 = 150g of 50% alcohol
20/35 x 350 = 200g of 95% alcohol

Where does 278 and 222ml come from??????

 answer to question by: Anonymous 222: 20 parts of 95%277: 25 parts of 50%

 Algebra by: DVN .5x + .95(500-x) = 350.5x + (.95*500) - (.95x) = 350.5x + 475 - .95x = 350(subtract 475 from both sides).5x - .95x = -125-.45x = -125x = 277.78 = ~278Therefore, 278mL of 50%, and (500-278=222)mL of 95% :)

 Thanks! by: Anonymous That helps a lot!

 Tic Tac Toe Allegation videos by: Ana These videos will help you to understand better these kind of questions. It's easy to learn but too long to explain to you in words/text.

 Dose Calculation by: Anonymous Thank so much to your kindly instruction. It is sound great on these program for preparing Pharmaceutical Technician Test.

 HI by: MUSA 95% 20 PARTS 7050% 25 PARTS TOTAL 45 PARTS WE NEED 500 ML OF 70% SO 500/45= 11.11 FOR EACH PART 20*11.11=222 ML FROM THE 95%25*11.11=278 FROM THE 50%

 Question by: Anonymous What the is title of the book you are referring to?

 easy by: Anonymous H=F-L/H-L x 500mlH=70-50/95-50 x 500mlH=20/45 x 500mlH= 0.44 x 500mlH=222ml of %95L=H-F/H-L x 500mlL=95-70/95-50 x 500mlL=25/45 x 500mlL=0.55 x 500mlL=278ml of %50

 I did it by: Fatin I was confused with this question and I kept trying to reach the mls used to determine the grams of the other percentages and I figure it out.I use proportion to find the volume of the two percentages so I will use it to get the gramsfirst I need the parts of each percentage and the total partsI have 20 part of the 95% and 20 parts of the 50%, the total is 45 parts350g/45parts = x /20 partsx= 350 x20/45x= 222.23 rounded to 222 ml of the 95%350g/45 parts= x/25partsx= 350 x 25/45x= 277.76 rounded to 278Then we use the same calculation to get the grams222 ml x 0.95= 211g178 ml x 0.5= 139gthe total will be the total grams of the desired percentage the 70%211 + 139= 350 g