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1) You prepare a stock solution (highly concentrated) of sugar water with a conc

ID: 3199506 • Letter: 1

Question

1) You prepare a stock solution (highly concentrated) of sugar water with a concentration of 500 mg/ml. You need to make a new solution that is half as concentrated and has a final volume of 100 ml.

Step one: Identify the concentration of your new solution: ____.

Step two: Identify how much volume of the stock solution you need AND how much water you need to make 100 ml of this new solution. Show your work. _________ of the stock solution _________ of water

2. Make a second, new solution that is 1/10 the concentration of the stock solution and that has a final volume of 100 ml. Show your work.

Explanation / Answer

step 1)

concentration is half of original = 500/2 = 250 mg/ml

step 2) final volume required = 100 ml

total sugar concentration required = 250*100 = 25000

since the original concentrate has sugar, and the water we add will have no sugar,

original concentrate to be added = concentration required/original concentrate = 25000/500 = 50 ml

hence to make 100 ml concentrate we need 50 ml stock solution and 50 ml water

2.

1/10 concentrate = 500/10 = 50 mg/ml

for 100 ml solution total concentrate required = 50*100 = 5000 mg

original concentrate to be added = concentration required/original concentrate = 5000/500 = 10 ml

hence 10 ml stock solution

rest 90 ml water to make 100 ml of solution with 1/10 concentration