1 Your friend who works in a research lab on campus is overw

1) 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).

a) 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?

b) 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?

c) 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?

d) 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?

Solution

a) 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?

Answer:

If you dissolve 600 mg of glucose in 500 ul of water, =600mg/0.5 mL = 1200mg/mL

Stock = 1200 mg/mL

Required = 22 mg/mL

Volume= 10mL

C1V1= C2V2

(stock)   (required)

V1=C2V2/C1

V1 = (22mg X 10 mL)/ 1200mg

= 0.18 mL

=180 uL

180 uL of stock + 9.820 uL of H2O gives 22mg/mL solution