imZerroo
Member
Hey guys, could someone please help me with these questions?
1. The sulfate content of a fertilizer was measured by dissolving 1.63 g of the fertilizer in 300 mL water, then slowly adding a solution of barium chloride until no further precipitation occurred. After filtration and drying the mass of precipitate was 1.81 g. Calculate the percentage of sulfate in the fertilizer. In addition calculate the percentage sulfur in the fertilizer (assuming that sulfate is the only source of sulfur).
2. To determine the sulfate concentration in a liquid fertilizer (aqueous solution), an analyst first diluted 50 mL of the fertilizer solution to 250 mL, pipetted out 25 mL of the dilute solution, added 200 mL water to it then precipitated the sulfate with barium nitrate solution. The precipitate was filtered, washed and dried to constant mass. In repeated experiments the mass of precipitate was 0.728 g, 0.773 g, 0.722 g, 0.732 g. As accurately as you can, calculate the percentage sulfate in the original fertilizer solution. Justify the procedure you followed.
Gravimetric analysis:
1. The phosphate content of a laundry washing powder (detergent) was determined as follows. 6.92 g of the powder was dissolved in approximately 500 mL water. A slight excess of a solution of magnesium chloride in an ammonia, ammonium chloride buffer was added to this with stirring until precipitation was complete. The precipitate was filtered off and dried; its mass was found to be 1.83 g. The precipitate is pure magnesium ammonium phosphate hexahydrate of formula, Mg(NH4)PO4.6H2O.
Calculate the number of moles of phosphorus in the precipitate and hence the percentage phosphorus in the original laundry powder.
The package this laundry powder came in carried a large letter P, meaning that its phosphorus content was less than 5%. Is this labeling justified?
Any help will me much much appreciated.
Thanks :]
1. The sulfate content of a fertilizer was measured by dissolving 1.63 g of the fertilizer in 300 mL water, then slowly adding a solution of barium chloride until no further precipitation occurred. After filtration and drying the mass of precipitate was 1.81 g. Calculate the percentage of sulfate in the fertilizer. In addition calculate the percentage sulfur in the fertilizer (assuming that sulfate is the only source of sulfur).
2. To determine the sulfate concentration in a liquid fertilizer (aqueous solution), an analyst first diluted 50 mL of the fertilizer solution to 250 mL, pipetted out 25 mL of the dilute solution, added 200 mL water to it then precipitated the sulfate with barium nitrate solution. The precipitate was filtered, washed and dried to constant mass. In repeated experiments the mass of precipitate was 0.728 g, 0.773 g, 0.722 g, 0.732 g. As accurately as you can, calculate the percentage sulfate in the original fertilizer solution. Justify the procedure you followed.
Gravimetric analysis:
1. The phosphate content of a laundry washing powder (detergent) was determined as follows. 6.92 g of the powder was dissolved in approximately 500 mL water. A slight excess of a solution of magnesium chloride in an ammonia, ammonium chloride buffer was added to this with stirring until precipitation was complete. The precipitate was filtered off and dried; its mass was found to be 1.83 g. The precipitate is pure magnesium ammonium phosphate hexahydrate of formula, Mg(NH4)PO4.6H2O.
Calculate the number of moles of phosphorus in the precipitate and hence the percentage phosphorus in the original laundry powder.
The package this laundry powder came in carried a large letter P, meaning that its phosphorus content was less than 5%. Is this labeling justified?
Any help will me much much appreciated.
Thanks :]