Portion is red is what I\'m having trouble with.Instructor said I would have to
ID: 786416 • Letter: P
Question
Portion is red is what I'm having trouble with.Instructor said I would have to use the proportional equation to convert M to mM units.. How does this end up being 30 ml? This only thing I need help with equation wise...
Secondly, I need to provide a brief step by step explaination/list of how I would put these calculations to use in a lab. Doesn't have to be too detailed. I'm just not too familiar with the names of all the intruments to mention, ect...
Practice Problems for Biochemistry I - Set I Describe (by performing the relevant calculation and by listing the steps involved) how to prepare 150 ml of 10 mM Tris-HCl buffer pH 7.8. The MW of Tris is 121. Calculate how much 40% sucrose stock solution is needed to prepare 300 ml of 2.5% sucrose solution. Describe (by calculation and by listing each step) how to prepare 1500 ml of 0.4 M glucose solution that contains 2 mM sodium chloride. The MW of glucose is 180.2 and you have a 0.1 M sodium chloride stock solution to use. ANSWER: 108.1 g of gluclose... and... 30 ml of 0.1 M sodium chloride stock solution inExplanation / Answer
1 M = 1 * 10^3 mM
so unit factor for converting M into mM is
1 = [ (1 * 10^3 mM) / 1M ]
Use equation of dilution
M1 * V1 = M2 *V2
V1 = M2 * V2 / M1
M1 = 0.1 M = 0.1 M * [ (1 * 10^3 mM) / 1M ] = 0.1 * 10^3 mM
M2 = 2 mM
V2 = 1500 mL
V1 = 2 mM * 1500 mL / (0.1 * 10^3 mM) = 30 mL
So you need 30 mL of 0.1 M NaCl solution
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You need to prepare 1500 mL of 0.4 M glucose solution which also 2 mM NaCl
You have calculated grams of glucose = 108.1 g. This is correct
1. Add 108.1 g of glucose in 1.5 L volumetric flask
2. Add 500 mL of water to the 1.5 L volumetric flask and shake the flask to dissolve glucose.
3. Add 30 mL of 0.1 M NaCl solution and shake the flask to make the solution homogeneous.
4. Add water to make the volume of solution in volumetric flask upto the mark of 1.5 L