  ## mixing solutions problem

by April
(MI, USA)

How much 75% ethanol is needed to make 300ml of 30% ethanol?
A. 80mL
B. 120mL
C. 180mL
D. 240mL

Would really appreciate it if someone could help me out by writing out the problem (show how to solve). Thank you

## Comments for mixing solutions problem

 Jan 18, 2012 alcohol by: Anonymous want-----X qty= solutionhave30%---- X 300 ml= 120 ml75%

 Jan 10, 2012 simple by: Riduan You can do both ways; 75%- - - 30 30% 0%- - - 45Now, the next step:30/75.300=120 mlor (C1)(V1) = (C2) (V2) (.30)(300) = (.75) (X) 90 /.75 = 120 ml

 Oct 27, 2011 Pharmacy Math Solutions by: Anonymous Calculate how much mixture or solution must be given so that the patient receives the correct dose of active ingredient.Requires 50mg of active ingredient using a 5% w/w mixture

 Jul 27, 2011 there is a short cut by: Anonymous Times the two that are close together and divide by the one that is far away!

 Jun 29, 2011 mixing solutions problem by: Anonymous How much 75% ethanol is needed to make 300ml of 30% ethanol?A. 80mLB. 120mLC. 180mLD. 240mLC1 x V1 = C2 x V230% x 300mL = 75% x 9000 = 75x 9000/75 = x 120mL = xanswer B.

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