A volume of 5oo ml of potassium sodium tartrate solution S1 of c1=0.21mol/l is to prepared. Determine the mass of hydrated potassium sodium tartrate of formula KNaC4H4O6.4H2O needed for this preparation .(molar atomic masses : H=1;C=12;O=16;Na=23;K=39)
To determine the mass of hydrated potassium sodium tartrate needed for the preparation of the solution S1, we need to calculate the number of moles of KNaC4H4O6.4H2O required.
The molar mass of KNaC4H4O6.4H2O can be calculated by:
(Molar mass of K) + (Molar mass of Na) + (Molar mass of C4H4O6) + (Molar mass of 4H2O)
= (39 g/mol) + (23 g/mol) + [(4 x (12 g/mol)) + (6 x (1 g/mol)) + (6 x (16 g/mol))] + [(4 x (2 x (1 g/mol)) + 4 x (16 g/mol))]
= 39 g/mol + 23 g/mol + (48 + 6 + 96) g/mol + (8 + 64) g/mol
= 39 g/mol + 23 g/mol + 150 g/mol + 72 g/mol
= 284 g/mol
Now, we can calculate the number of moles of KNaC4H4O6.4H2O required using the formula:
Number of moles = Concentration × Volume
Given that the concentration (C1) is 0.21 mol/L and the volume is 500 mL (convert to L by dividing by 1000):
Number of moles = 0.21 mol/L × (500 mL / 1000)
Number of moles = 0.21 mol/L × 0.5 L
Number of moles = 0.105 mol
Finally, we can calculate the mass of hydrated potassium sodium tartrate needed:
Mass = Number of moles × Molar mass
Mass = 0.105 mol × 284 g/mol
Mass = 29.82 g
Therefore, to prepare the solution S1, you would need approximately 29.82 grams of hydrated potassium sodium tartrate.