Guest guest Posted July 24, 2006 Report Share Posted July 24, 2006 Hello, I had the answer to both questions but I didn't know how to solve the problem. That's the answers that I have. You made it seem so easy to understand. Thank You! pharmacy_000 <pharmacy_000@...> wrote: Hello, I will say how I'd do these problems, but please keep in mind that I am not a mod or a TEXTpert, so please wait for one of them to confirm the method/answer. Now, for these two problems I would solve them using C1 x V1 = C2 x V2 instead of alligation. C stands for Concentration and V stands for Volume. C1/V1 means the concentration and volume you have and C2/V2 means the desired concentration and volume. Problem #1 This problem involves ratio. 1:50 v/v means 1 ml per 50 ml (both being ml, since this is a volume in volume solution). You use this ratio to find out the concentration percentage. Just set it equal to x/100 ml 1 ml x ml ----- = ------ 50 ml 100 ml 100 ml * 1 ml = 50 ml * x ml x = 2 ml Since you get the answer of 2 ml per 100 ml this would be a 2% solution. Now use C1 * V1 = C2 * V2. You have 100 ml of a 50% solution, so C1 = 50% and V1= 100 ml And you have a 2% solution and need to know how many ml C1 * V1 = C2 * V2 50% multiplied by 100 ml = 2 % multiplied by x ml 5000 = 2x Ans= 2500 ml Problem #2 We will use C1 * V1 = C2 * V2 again. The ratio we have here is 10 mg/5 ml. Let's find the concentration percentage by setting this ratio equal to x/100 ml. Keep in mind that percentage concentrations of w/v mean GRAMS per ml and we're working with mg here. We're going to have to switch it to grams either at the start or after calculating. 10 mg x mg ----- = ----- 5 ml 100 ml 200 mg/100 ml = ..2 g/100 ml or .2% Now: C1 * V1 = C2 * V2 100 ml * .2% = 500 ml * x percent Ans: 0.04 % > > Two more allegation problems I need help with. > > #1 How many milliliters of a 1:50 v/v solution of aspirin in alcohol > can be made from 100 mL of 50% v/v solution? > > #2 If 100 mL of a Choledyl elixir containing 10mg/5mL active > ingredient (oxtriphylline) is diluted to 5oo mL, what will be the > final strength of oxtriphylline? > --------------------------------- Talk is cheap. Use Messenger to make PC-to-Phone calls. Great rates starting at 1¢/min. Quote Link to comment Share on other sites More sharing options...
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