Math Review 1 - C1V1=C2V2

Math Review 1 Show all calculations and remember units. 1. Find the mass of glucose that must be used to prepare 500 mL of a 8% w/v aqueous solution. M= C x V 8g/dL x 5dL = 40g 2. What volume of 0.45% w/v aqueous NaCl solution can be prepared from 82.5g of NaCl? V=M/C 82.5g/0.45g/dL =183.3dL 3. If you have 18g of NaCl in 200 mL of solvent, what %w/v solution will you have? C=M/V 18g/2dL = 9% 4. If you use 20 mL of a 5% w/v solution and dilute it up to a final volume of 500 mL, what is the concentration of the working stock? C1V1 = C2V2 5g/dL x 0.2dL 5 = 0.2g/dL =0.2% 5. What volume of water must be added to 200 mL of a 1g/100mL NaCl solution to give a final 0.5% w/v NaCl solution? V2 = (C1 V1) C2 V2 = (1g/dL x 2dL) 0.5g/dL V2 = 4dL Therefore 2dL or 200mL must be added. 6. What volume of a 20g/100mL stock solution would be required to prepare 0.15L of a 5g/100mL solution of KOH? V1 = (C2 V2) C1 V1 = (5g/dL x 1.5dL) 20g/dL V1 = 0.38dL 7. You used 80mL of a NaCl stock solution and diluted it to 100 mL to prepare a 0.2g/100mL solution. What was the concentration or the stock solution in %w/v? C1 = (C2 V2) V1 C1 =. (0.2g/dL x 1dL ) 0.8dL C1= 0.25g/dL 8. You had 200 mL of 0.1%w/v creatinine and diluted it with 300mL of solvent. What is the concentration of the working solution and what is the dilution factor? D1 = (V1 + V2) V1 D1= (200mL + 300mL) 200mL D1= 2.5 C2 = (C1V1) V2 C2 = 0.04 9. If you have 0.1L of 2g/100mL sodium tungstate, how would you dilute it to prepare a 100mg/ 100mL working solution? V2 = (C1V1) C2 V2 = (2g/dL x 1dL) 0.1g/dL V2 = 20dL 20dL - 1dL = 19dL Add 19dL to 0.1L of the 2g/100ml sodium tungstate. 10. Describe how to make 2.55L of 3% (w/v) aqueous solution of sodium chloride. M = VxC M = 25.5dL x 3g/dL M = 76.5g Mix 76.5g pf sodium chloride with water, top up to a final volume 2.55L