1.a) If there are 6.0 mg of K+ contaminant per liter of water sample, calculate
ID: 847078 • Letter: 1
Question
1.a) If there are 6.0 mg of K+ contaminant per liter of water sample, calculate the number of moles of K+ per liter. b)Calculate the weight of K+ in a second sample of water that contains 200 µmol K+/L. 2. If there are 12.0 mg of dissolved oxygen per liter of water at 300C, 1 atm, calculate the number of moles of molecular oxygen and the molarity of dissolved molecular oxygen. 3. Calculate the number of molecules of hydrocodone per microliter of a 30.0 nM solution. 4. If 6.7 g of sodium acetate or 6.7 g of magnesium acetate is dissolved in a total volume of 0.200 L of water calculate a) the molarity of sodium acetate b) the molarity of magnesium acetate c) the molarity of acetate ion in each solution 5. How many grams of EDTA tetrahydrate are needed to prepare 500 mL of a 0.010 M solution? 6.a) How would you prepare 100 mL of a 0.040 M solution of acetate ion using sodium acetate? b) Using magnesium acetate? 7. The concentration of ampicillin in a stock solution is 5.00 x 103 µg/mL. (Ampicillin fw 349.41 g/mol) Calculate: a) µg of ampicillin in 0.100 ml of the solution b) µmol of ampicillin in 0.100 ml of the solution c) molarity of ampicillin d) how to prepare 30.0 mL of a working solution with a concentration of 10.0 ݵg/ml 8. Beta mercaptoethanol is available as a 98%(w/w) solution (sp gr 1.114 g/ml) describe the prepartion of 0.100 L of a 50mM solution? 9. The concentration of potassium ion in a standard solution is 1000 ppm (w/v). What is the molarity of K+? 10. Prepare 100.0 ml of 2.0 M solution of acid and base from each listed stock a) 6 N stock solutions of H2SO4 and of NaOH b) Concentrated H2SO4 and NaOH solid. 11. A 100.0 µL aliquot of a solution of EcoR1 (10 units/mL) is added to 100 ml of buffer. Calculate a) the dilution factor and b) the final concentration of EcoRI in the buffer c) prepare 1.5 ml of 1.0 units/ml solution starting with the 10.0 units/ml stock 12. a) Calculate how you would prepare 500 mL of a 250mM phosphate buffer at pH 7.2 using the appropriate acid and potassium salts. b) Repeat the buffer calculation at pH 3.5.
Explanation / Answer
11. a. dilution factor = 10^-2
b. final concentration = 1 micro litre
c. dilution 1/10th by adding 100 ml water to 1.5 ml
12. a. dissolve 69 g of NaH2PO4
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.