Need help on quick calc problem

[Pharm0307]

What is the ratio strength of 100 ml containing a 1:50 povidone iodine solution diluted to 1,000 ml?

The answer is 1:500, but I don't understand how to solve this! Maybe I'm just reading the question wrong or something. Anyone care to help me out?

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[bbooss]

What is the ratio strength of 100 ml containing a 1:50 povidone iodine solution diluted to 1,000 ml?

The answer is 1:500, but I don't understand how to solve this! Maybe I'm just reading the question wrong or something. Anyone care to help me out?

C1V1=C2V2 so, 1:50*100=x *1000 so x=0.002 which is 2 in 1000
to get the ratio 2 in 1000 is same as 1 in 500 1:500

 

[doingit4mykid]

What is the ratio strength of 100 ml containing a 1:50 povidone iodine solution diluted to 1,000 ml?

The answer is 1:500, but I don't understand how to solve this! Maybe I'm just reading the question wrong or something. Anyone care to help me out?

Another way to clarify - if needed:

1:50 ratio strength is 2% (1/50 * 100).
2% w/v means 2g in 100ml. So we now know that the 100ml of the 1:500 solution contains 2g of active ingredient.

If we dilute this 2g to 1000ml, we have 2g of active ingredient in the 1000ml. We now want to determine the concentration of this new dilution ,therefore:

2g in 1000ml -- then how many grams in 100ml? We get 0.2g.

So it is a 0.2g to 100ml ratio - which is 1:500.

 

[watson lee]

The original ratio strength of providone iodine solution is: 1:50
volume changes from 100ml to 1000ml.....1/10

so the ration strength (1:50) will be reduced 10 fold.....to more diluted... 1:500

 

[Naplesmark]

To all. these type of questions are included in the first 12 questions to slow you down. Know this question and answer. Remember that the first 12 question are made to slow you down. This is what all professionally given try to do. Do not allow the exam to slow you down or you will not have time to finish. When you read about someone not finishing this is what happened they spent too much time at the beginning.

 

[aabdraff57]

What is the ratio strength of 100 ml containing a 1:50 povidone iodine solution diluted to 1,000 ml?

Q1C1 = Q2C2

(100 ml)(1:50) = (1000 ml) C2

Convert the 1:50 to percentage: 2%. Replace in the formula.

100 ml x 2% = 1000 ml x C2

C2 = [100 ml x 2%] / 1000 ml

C2 = 0.2% Convert this percentage to ratio 1:500. Hope that helps.