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??????


Comments for Allegation Medial

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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 = -125
x = 277.78 = ~278

Therefore, 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
70
50% 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 500ml
H=70-50/95-50 x 500ml
H=20/45 x 500ml
H= 0.44 x 500ml
H=222ml of %95

L=H-F/H-L x 500ml
L=95-70/95-50 x 500ml
L=25/45 x 500ml
L=0.55 x 500ml
L=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 grams
first I need the parts of each percentage and the total parts
I have 20 part of the 95% and 20 parts of the 50%, the total is 45 parts

350g/45parts = x /20 parts
x= 350 x20/45
x= 222.23 rounded to 222 ml of the 95%

350g/45 parts= x/25parts
x= 350 x 25/45
x= 277.76 rounded to 278
Then we use the same calculation to get the grams
222 ml x 0.95= 211g
178 ml x 0.5= 139g
the total will be the total grams of the desired percentage the 70%
211 + 139= 350 g

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