Question

How would you prepare the following solutions? Unless stated otherwise, assume that the solvent is purified water and that you will dissolve the solute in a lesser amount of solvent and then “bring the solution to volume”

CuSO₄ FW 159.61

NaCl FW 58.44

CaCl FW 111.0

Na₂SO₄^. 10H₂O FW 322.04

1. 100 ml of AgNO₃ at 2 g/ml

2. 250 ml of NaCl at 2 mg/ml

3. 0.75 L of CuSO₄ at 50mg/ml

4. 250 ml KCl at 20 mg/ml

5. 50 ml of 0.1% (w/v) AgNO₃

6. 500 ml of 1%( w/v) NaCl

7. 10 ml of 6% (w/v) CuSO₄

8. 200 ml of 2% (w/v) KCl

9. 25ml of 20% (v/v) Methanol

10. 2L of 70% (v/v) Ethanol

11. 10 ml of 0.2% (v/v) DMSO

12. 50 ml of 3% (v/v) Propanol

13. 250 ml 12 mM CuSO4

14. 500 ml 0.25M NaCl

15. 500 ml 25mM CaCl

16. 100 ml 300 mM Na₂SO₄

17.100 ml of 5:3:2 ethylene: chloroform: isoamyl alcohol

18. Convert 50 ppm to g/L

19. Convert 50 ppm to mg/L

20. Convert 5 ppb to ul/l

21. Convert 3 ppm to l/ml

22. Convert 350 ppm to ml/L

23. 300 ppb Cadmium (solid)

Answer 1

Answer:

Use purified water as solvent for dilution. First dilute the solute in lesser amount of solvent and then add more solvent to make the final volume as required.

1. 100 ml of AgNO3 at 2 g/ml

• Add 200g of AgNO3 and make total volume 100ml

2. 250 ml of NaCl at 2 mg/ml

• Add 500mg NaCl and make total volume 250ml

3. 0.75 L of CuSO4 at 50mg/ml

• Add 37.5g CuSO4 and make total volume 750ml

4. 250 ml KCl at 20 mg/ml

• Add 5g KCl and make final volume 250ml

5. 50 ml of 0.1% (w/v) AgNO3

• Add 0.05g (50mg) of AgNO3 and make total volume 50ml

6. 500 ml of 1%( w/v) NaCl

• Add 5g NaCl and make final volume 500ml

7. 10 ml of 6% (w/v) CuSO4

• Add 0.6g (600mg) CuSO4 and make final volume 10ml

8. 200 ml of 2% (w/v) KCl

• Add 4g KCl and make final volume 200ml

9. 25ml of 20% (v/v) Methanol

• Add 5ml Methanol + 20ml solvent (water)

10. 2L of 70% (v/v) Ethanol

• Add 1400ml Ethanol to 600ml solvent (water)

11. 10 ml of 0.2% (v/v) DMSO

• Add 0.02ml (20ul) DMSO to 9.98ml water

12. 50 ml of 3% (v/v) Propanol

• Add 1.5ml Propanol to 48.5ml solvent

13. 250 ml 12 mM CuSO4

• Add 479mg CuSO4 and make final volume 250ml with water

14. 500 ml 0.25M NaCl

• Add 7.305g NaCl and make final volume 500ml with water

15. 500 ml 25mM CaCl

• Add 1.3875g CaCl and make final volume 500ml with water.

16. 100 ml 300 mM Na2SO4

• Add 4.26g Na2SO4 and make final volume 100ml OR
• Add 9.66g Na2SO4.10H2O and make final volume 100ml

17.100 ml of 5:3:2 ethylene: chloroform: isoamyl alcohol

• Add 50ml ethylene + 30ml chloroform + 20ml isoamyl alcohol

18. Convert 50 ppm to g/L

• 50ppm = 50mg/L = 0.05g/L

19. Convert 50 ppm to mg/L

• 50ppm = 50mg/L

20. Convert 5 ppb to ul/l

• 5ppb = 0.005ul/L

21. Convert 3 ppm to l/ml - ** units are not clear in question

22. Convert 350 ppm to ml/L

• 350ppm = 0.350 ml/L