Final answer:
To calculate the % purity of sodium carbonate, the moles of sulfuric acid used in the titration are converted into the moles of sodium carbonate, which are then multiplied by the molar mass to find the mass of the pure compound. This mass is then divided by the mass of the impure sample and multiplied by 100 to find the percentage purity, which is approximately 37.96% in this case.
Step-by-step explanation:
To calculate the % purity of sodium carbonate in the given sample, we need to first determine the amount of sodium carbonate that has reacted with the sulfuric acid in the titration process.
Sodium carbonate (Na2CO3) reacts with sulfuric acid (H2SO4) in a 1:1 molar ratio according to the equation:
Na2CO3 + H2SO4 → Na2SO4 + H2O + CO2
Using the molarity and volume of the H2SO4 solution, we can calculate the moles of Na2CO3 that have reacted:
Moles of H2SO4 = 0.10 M × 0.0305 L = 0.00305 mol
Since the molar ratio between Na2CO3 and H2SO4 is 1:1, moles of Na2CO3 = moles of H2SO4.
Now we can calculate the mass of pure Na2CO3:
Mass of Na2CO3 = moles × molar mass of Na2CO3
= 0.00305 mol × 105.99 g/mol
= 0.3233 g
Finally, we determine the % purity:
% Purity = (Mass of pure Na2CO3 / Mass of impure sample) × 100
= (0.3233 g / 0.852 g) × 100
≈ 37.96%
Thus, the percentage purity of the sodium carbonate sample is approximately 37.96%.