Question

Please help with solving these problems I am having a hard time trying to work them out

1. You need to make a 15% solution using 25 ml of a 80 % stock solution. How much sterile saline do you need to add to make this product? Round your answer to one decimal place (tenths), where appropriate.

2. Your are given 25 ml of a 80% solution and told to add (not dilute to) 275 ml. What will the final percent strength of the diluted solution be? Round your answer to on decimal plac (tenths), where appropriate.

3.  You need to make a 10% solution using 2 ml of a 55 % stock solution. How much sterile saline do you need to add to make this product? Round your answer to one decimal place (tenths), where appropriate

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Answer 1

Ans-1 Given : CL = 15% Ca concentration VI = 25ml Strength C2=80% Ve volume V2 = ? (let it be x) Formula : CIVI = C2 V2. 15x 25 = 80 X X ...215 X 23 = 75 & x=4.6875 x=4.7 ml =12 4.7 ml Ns needed to add to make this product Ans 2 : V1 = 25ml C1 = 80% V2 = 275 m) C2 = 2 Civi = C2 V 2. 80 x 25 = C2 X 275 A C2 = 80 x 25 = 80 = 7.2727 275 11 i C2=7.3 % 1 Final % strength of the diluted solution as 73%.

ans-3: Ci=10% VI = 2ml C2 = 55% 12=x/? → CIVI = C2 V2 . 10x2=55 X 2 - 1 X 2 =4 = 0.3636 55 | i V2=0.4 mit ..014 mins need to add to make this product.