[Lizzy]

How would you make 200 ml of a solution with the following composition?
 50mM Tris, 50 mM NACl, 0.1 mM EDTA, 1.0% Triton X

Molecular Wieghts in (g/mole)
Tris 121.1
Triton X 628
EDTA 372.2
NaCl 58.2

If someone could walk me through this that would be great

[Archer]

Start by working out how to make 1Lt then divide the values by 5.

If you wanted to make a 1M solution of EDTA how much would you add to a 1 Lt.

[Babcock_Hall]

According to Forum rules, you must show an attempt.  I will give you a hint to get started.  With respect to Triton X 100, you will have to use different units versus the other components.

[Lizzy]

According to Forum rules, you must show an attempt.  I will give you a hint to get started.  With respect to Triton X 100, you will have to use different units versus the other components.

Okay so this is what I've did for using the given mMs and the given molecular weight
My work
 50= 0.05 M Tris
 0.05 M= x moles/0.2 L x=0.01 moles
 0.01 moles=x grams over/ 121.1 x =1.211 grams

 50 mM NaCl=0.05 M NaCl
 0.05M= x moles/ 0.2 L x= 0.01 moles
 0.01 moles= x grams/ 58.2 x=0.582 grams

0.1 mM EDTA= 0.0001 M
0.0001 M = x moles/.2L x = 0.005
 0.005 moles = x grams/372.2g x=1.861

And I don't really understand how to solve for triton even with your hint

[Babcock_Hall]

Percentage methods have the potential to be ambiguous.  One interpretation is that the percentage refers to the mass of a solid or to the volume of a liquid in a solution with a final volume of 100 mL.  In other words, if I were told that a certain solution was 10% sucrose, I would take 10 grams of sucrose into a final volume of solution of 100 mL using water, or something proportional to this.

[Lizzy]

Okay that makes a lot more sense, does the rest of it look right though? Or is it wrong?

[Babcock_Hall]

Everything else looks OK.

[Yggdrasil]

Usually when concentrations are given in % values, it is specified whether the concentration is a %(w/v) or %(v/v).  A 1% (w/v) solution contains 1 g or solute per 100 mL of solution.  A 1% (v/v) solution contains 1 mL of solute per 100 mL of solution.  Triton X-100 is a liquid, so 1% probably means 1% (v/v).