Your friend who works in a research lab on campus is overwhelmed with projects a
ID: 489028 • Letter: Y
Question
Your friend who works in a research lab on campus is overwhelmed with projects and needs your help! Suit up and make the following stock solutions (water will be your diluent). If you dissolve 600 mg of glucose in 500 ul of water, how much of this solution do you need to use to make 10 ml of 22 mg/ml glucose? You want to make 35 ml of a solution of potassium chloride in water at 450 mg/ml. If you have 22 ml of potassium chloride at 1.1 g/ml in water, how would you make the desired solution? You have 100 ml each of 300 mg/ml sodium phosphate, 350 mg/ml sodium chloride, and 150 mg/ml potassium nitrate. You want to make one liter of a solution containing 1.0 mg/ml sodium phosphate, 13 mg/ml sodium chloride, and 15 mg/ml potassium nitrate. How much of each starting solution do you need to use and how much water do you need to add? Do you have enough materials to make this solution? You have 100 ml each of 150 mg/ml human chorionic gonadotropin, 25x HCG buffer, and 450 mM potassium chloride. You want to make one liter of a solution that is 1.8 mg/ml human chorionic gonadotropin, 1x HCG buffer, and 40.5mM potassium chloride How much of each starting solution will you need to use and how much water do you need to add? Do you have enough materials to make this solution?Explanation / Answer
a) We have 600 mg of glucose in 0.5 mL water (conentration = 1200 mg/mL); we need to make 10 mL of 22 mg/mL
So, the glucose concentration = 1200 mg/mL (M1), V1 =?
M2 = 22 mg/mL; V2 = 10 mL
So, V1 = M2V2/M1 = (22 mg/mL)* (10mL)/ (1200 mg/mL) = 0.183 mL
We need 183 uL of the solution needed to make make 10 mL of 22 mg/mL solution.
b) required solution : 35 mL (V2)of KCl in 450 mg/mL(M2)
we have 22 mL of KCl at 1.1 g/mL = 1100mg/mL (M1), we need to calculate volume required = V1
V1 = M2V2/M1 = (450 mg/mL)*(35 mL) / (1100 mg/mL) = 14.3 mL
Take 14.3 mL of KCl at 1.1 g/mL solution and add 20.7 mL of water. The resulting solution is 35 mL of KCl in 450 mg/mL.
c) We need to make 1 L containing 1 mg/mL sodium phosphate, 13 mg/mL of NaCl, and 15 mg/mL KNO3.
Volume of sodium phosphate V1 = M2V2/M1 = (1 mg/mL) * (1000 mL)/ (300 mg/mL) = 3.33 mL
Volume of NaCl V1 = M2V2/M1 = (13 mg/mL) * (1000 mL)/ (350 mg/mL) = 37.14 mL
Volume of potassium Nitrate V1 = M2V2/M1 = (15 mg/mL) * (1000 mL)/ (150 mg/mL) = 100 mL
we need to take 3.33 mL (300 mg/mL ) sodium phosphate solution +
37.14 mL of (13 mg/mL) of NaCl solution + 100 mL of (15 mg/mL) potassium nitrate in a volume metric flask and add 859.53 mL of water to make 1 L required solution.
d)Required Solution ; 1.8 mg/mL of HCG, 1X HCG buffer and 40.5 mM KCl of 1 L solution.
Volume of HCG V1 = M2V2/M1 = (1.8 mg/mL) * (1000 mL)/ (150 mg/mL) = 12 mL
Volume of 25X HCG buffer V1 = M2V2/M1 = (1X) * (1000 mL)/ (25 X) = 40 mL
Volume of KCl V1 = M2V2/M1 = (4.5 mg/mL) * (1000 mL)/ (450 mg/mL) = 10 mL
So, we need 12 mL of HCG (1.8 mg/mL), 40 mL of 25X HCG buffer and 10 mL of (450 mg/mL) KCl solution and remianing add water (938 mL) to make the required 1 L solution.
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