# User:Melissa Novy/Notebook/CHEM-571/2012/09/18

(Difference between revisions)
 Revision as of 12:44, 18 September 2012 (view source) (Autocreate 2012/09/18 Entry for User:Melissa_Novy/Notebook/CHEM-571)← Previous diff Revision as of 13:53, 18 September 2012 (view source)Next diff → Line 15: Line 15: - ==Entry title== + ==0.2 M Sodium Phosphate Buffer in H2O== - * Insert content here... + * Calculations: + ** 250 mL of 0.2 M sodium phosphate stock solution requires the following: + '''MW sodium phosphate''': 163.94 g/mol + '''Mass sodium phosphate''': + 250 mL × (10-3 L/mL) × 0.2 M × (10-3 mol/mmol) × 163.94 g/mol = 13.4035 g sodium phosphate + '''Actual mass sodium phosphate''': 13.4031 g + '''Actual concentration''': + 13.4031 g × (1 mol/163.94 g) × (1/0.25 L) = 0.327 M in H2O + * 13.4031 g of sodium phosphate was dissolved in about 200 mL of H2O. + * The pH was adjusted to 7.00 by adding 20 mL of 1 N HCl dropwise. + * The solution was then diluted to a final volume of 250 mL with additional H2O.

## Revision as of 13:53, 18 September 2012

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## 0.2 M Sodium Phosphate Buffer in H2O

• Calculations:
• 250 mL of 0.2 M sodium phosphate stock solution requires the following:
```  MW sodium phosphate: 163.94 g/mol
Mass sodium phosphate:
250 mL × (10-3 L/mL) × 0.2 M × (10-3 mol/mmol) × 163.94 g/mol = 13.4035 g sodium phosphate
Actual mass sodium phosphate: 13.4031 g
Actual concentration:
13.4031 g × (1 mol/163.94 g) × (1/0.25 L) = 0.327 M in H2O
```
• 13.4031 g of sodium phosphate was dissolved in about 200 mL of H2O.
• The pH was adjusted to 7.00 by adding 20 mL of 1 N HCl dropwise.
• The solution was then diluted to a final volume of 250 mL with additional H2O.