fill the blanks in the box: 2- Calculate and Illustrate how you would make four

Question

fill the blanks in the box:

2- Calculate and Illustrate how you would make four serial 3-fold dilutions such that each tube has a volume of 6 mL. There should be at least 3 mL in each tube following the preparation of all dilutions, because that is a minimal requirement for this particular experimental setup.

Stock Conc Desired Conc. n-fold Dilution Final Volume Solution 100 mL Vols. of Stock Pipet 10 mL (+90 ml in Working(Stock/Desired) of Working and Water to Solution 1 M 0.1 M 10 water) 2.2 M 0.4 M 5.5 50 mL 9.1 mL (+40.9 mL water) 0.5 M 4 M 0.2 M 0.2 M 2.5 mM 1.5 M 25 mM 40 mM 200 mL 200 mL 240 mL 300 mL Q: What ifyou had a stock solution 0.1 M and you need a working solution of 1.0 M? Note that often times, stock solutions are supplied as 10 X or 100 X concentrates, meaning the n-fold dilution will be 10 or 100, respectively, for a working solution at IX final concentration (typical). [The number in front of the X is the n-fold dilution to prepare a 1X working solution] So ifyou had a 25 X Stock solution, how would you prepare 1 L of Working Solution at 1 X final concentration? Your answer here

Explanation / Answer

Step 1

Inorder to explain above problem we should know theory of serial dilutions

V1M1 = V2M2

Step 2 : here we are having M and mM solutions

We know 1mM = 0.001M

Case 1- 0.5M to 25 mM in 200ml

Here M1= 0.5M

M2 = 25 mM (0.025M)

V2. = 200ml

So V1 = V2 M2/ M1

=( 0.025 )(200)/0.5

= 10 ml

n fold dilution is 10

Volume of stock solution and water to pipet is 10ml (+190 ml of water)

Case 2 - 4 M to 1.5M in 200ml

Here M1 = 4M

M2 = 1.5 M

V2 = 200ml

So V1= V2M2/M1

=1.5 x 200/ 4

= 75 ml

So n fold dilution is 75

Volume of stock solution and water to pipet is 75 ml (125 ml of water)

Case 3 -. 0.2 M to 25mM in 240 ml

Here M1 = 0.2M

M2= 25 mM (0.025M)

V2 = 240ml

So V1 = 0.025x 240/0.2

= 30 ml

So nfold dilution is 30

Volume of stock and water to pipet is 30 (+210ml of water)

Case 4 - 0.2 M to 40mM in 300 ml

Here M1 = 0.2 M

M 2 = 40mM (0.04M)

V2= 300ml

So V1 .= 0.04x 300/0.2

= 60 ml

nfold dilution is 60

Volume of stock and water to pipet is 60 ml(+240ml of water)

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