25 0 Ml Of Warm Water example essay topic

Introduction The purpose of this lab is to test the preparation of an iron salt to determine if it is a reliable and productive method. The point of the lab is to study the yield of the salt that could be obtained from the reaction, and the purity of the salt produced. To prepare the salt, specific instructions from a "medical journal" were used to obtain a salt precipitate. Experimental 7.50 g Fe (NH 4) 2 (SO) 4) 2 6 H 2 O was weighed on a top-loading balance and put in 25.0 mL of warm water mixed with 1.00 mL of 6.00 M sulfuric acid. The mixture was cautiously heated to steaming and stirred.

After the ferrous oxalate precipitate settled, the supernatant liquid was decanted. The oxalate was stirred with 25.0 mL of warm water and was again decanted. 15.0 mL of 1.80 M potassium oxalate solution was added to the solid and the solution was heated to 40.0^0 C. 16.0 mL of 7.50% H 2 O 2 was added while the liquid was gently stirred, all while making sure the temperature stayed near 40^0 C. Ferric hydroxide formed as a precipitate. The precipitate was dissolved by heating the mixture to near boiling, adding 8.00 mL of oxalic acid, and then adding a further small portion drop-wise.

About 56.0 mL of lime green solution remained. 15.0 mL of ethanol was next added to the hot solution. The remaining precipitate crystals were dissolved again by heating, after which the solution was allowed to cool. The product was obtained by vacuum filtration. The crystals that formed were washed a total of three times with 5.00 mL of a 1: 1 water-ethanol mixture, twice with 5.00 mL of acetone, and dried by vacuum filtration. Using a top loading balance, an empty test tube was weighed, with its mass being 19.38 g.

Next, the iron salt was placed in the test tube and weighed, with its mass being 22.90 g. The next part of the lab involved analyzing the oxalate. A 50.0 mL burette was cleaned with D.I. water and two 5.00 mL portions of 0.100 N KMnO 4 and filled with 0.100 N KMnO 4.0. 1012 g of the salt were dissolved in the 20.0 ml of 6.00 M sulfuric acid and heated to boiling. For the second sample, 0.1092 g were dissolved in the sulfuric acid).

The hot solution was titrated with the KmnO 4 solution until it turned a pink tinge. This process was repeated again for a second trial. For the first trial, it took 12.98 mL to titrate, and for the second sample, it took 13.01 mL to titrate. The burette was next drained and rinsed with 5.00% sodium bisulfate to remove stains on the glass that might have been caused by permanganate.

Finally, the percent weight of the oxalate was calculated. The final part of the lab involved the analysis of the iron and potassium ions... 2014 g of the iron salt was weighed on an analytical balance and was first dissolved in 10.0 mL of warm water. 2.00 g of Do wex 50 resin was next weighed out. The resin was rinsed until it had the same pH as the D.I. water and added to the salt solution. The solution was next stirred for five minutes.

The contents were put into a 250 mL beaker through a filter paper. Water was next added until a volume of 100 mL was obtained. A stirring bar was added to the beaker, and a pH electrode was placed in the beaker. A burette was placed above the solution, containing a 0.100 M NaOH solution. The initial pH of this first solution was 2.13. NaOH was added in 1.00 mL increments until the pH reached 3.62.

NaOH was next added in 0.500 mL increments until the pH reached 5.90. Next, NaOH was added in 1.00 mL increments until the pH reached 7.25. Finally, 0.500 mL increments were added again until the pH reached 11.0. At each addition of NaOH, the pH was recorded so a titration curve could be constructed.

The second sample, starting with a pH of 2.23, was used in the exact same manner to calculate a curve. mL KmnO 4 Titrated Grams of Iron Salt 12.98. 1012 13.01. 1092 Avg: 12.995 mL Avg: . Percent Yield: The reaction for the salt is given by: Fe (NH 4) 2 (SO) 4) 2 6 H 2 O 'a FeC 2 O 4 'a K 3 Fe (C 2 O 4) 3 3 H 2 O This shows the mole ratio of reagent to product is 1: 1. The percent potassium and percent iron seem to be rather high.

This error probably occurred because of miscalculations in creating the titration curve, where mistakes could easily occur. Other errors in the experiment could have occurred in the preparation of the salt, where the long complicated creation process could also result in errors. The oxalate, potassium, and iron analysis was relatively straightforward and probably did not have any errors. Approximately half of the 9.40 g final sample is oxalate. The potassium and iron values seem to be about 20-25% higher each than they should be. A reasonable potassium percentage should be somewhere around 45%, while a reasonable iron percentage would be somewhere around 25%.