One of the possible systematic error that may occur in this experiment is that the hydrated (II) ammonium sulfate is contaminated as the iron (II) salt was left uncovered. The iron (II) salt was prepared by the lab assistant and the salt was left at the table uncovered for students to scoop the desired amount of salt they want. The iron (II) salt might be contaminated by dust particles and even saliva. This would cause the standard iron (II) solution to have less iron (II) salt in it and this means that less potassium permanganate solution is needed to titrate the iron (II) solution. This is a systematic error because the iron (II) solution used throughout the experiment. The only way to reduce the systematic error and improve the accuracy is to place the iron (II) salt in a sterile area and to make sure the lid of the iron (II) salt is closed. Another systematic error that may occur is that the burette, pipettes and measuring cylinder used in the experiment is wrongly calibrated by the manufacturer. This would result in more or less solution than the required amount of solution in the experiment. For example, 25.00mL of Iron (II) solution was retrieved using a pipette, and if the pipette was wrongly calibrated and …show more content…
In order for the reaction take place, the iron (II) solution is swirled so that the potassium permanganate added would be combined with the iron (II) solution. Some swirling rate might be faster and some slower. When the swirling rate is slower, some of the iron (II) solution would not be able to combine with the potassium permanganate solution. This random error would cause some results to be lower or higher than the actual. The only possible solution to improve the precision of the result is to use a magnetic stirrer to get a constant swirling
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
While the solution dissolved, 50 mL of distilled water was added to a 150 mL beaker and heated on the hot plate. When the solution started to boil 2.65 grams of Na2SiO3*5H2O was added to the beaker with a stir bar and heated to a gentle boil. When both solutions began to boil, the sodium silicate solution was slowly added to the sodium aluminate. The solution was kept at 900C for 60 minutes and stirred with stir bar. After 60 minutes, the zeolite solution was cooled for 5 minutes and for the magnetized zeolite , 0.78 grams of FeCl3 and 0.39 grams of FeSO4*7H2O was added to the flask and stirred until the iron parts dissolved.
Marwah Alabbad Post lab 10/21/15 Question 1: 1. Experiment 1: Number of trails NaOH concentration (M) Volume of HCl solution (mL) Initial volume of NaOH(mL) final volume of NaOH(mL) The volume of NaOH to titrate HCl (mL) Concentration of HCl (M) 1st 0.1023 25.0 10.05 36.12 26.07 0.085 2nd 0.1023 25.0 5.74 31.40 25.66 0.105 3rd 0.1023 25.0 9.84 35.52 25.68 0.105 First trail calculation: 0.02607L× (0.1023mole NaOH/1L)×(1 mol of HCL/1 mol of NaOH)×(1/0.025)= 0.085M of HCl
In the first part of the experiment, Part A, the standard solutions were prepared. As a whole, the experiment was conducted by four people, however, for Part A, the group was split in two to prepare the two different solutions. Calibrations curves were created for the standard solutions of both Red 40 and Blue 1. Each solution was treated with a serial 2-fold dilution to gain different concentrations of each solution.
The goal of this experiment is to find out what is the identity of the unknown hydrate? To answer this question first, we should know what a hydrate, and how to identify a hydrate using the law of constant proportions. A hydrate is a pure substance because it contains water molecules embedded in its crystal structure that does not vary. By heating the unknown hydrate, we can calculate the mass of the hydrated, and the percentage of water in the hydrate.
The lab started off by measuring critical materials for the lab: the mass of an an empty 100 mL beaker, mass of beaker and copper chloride together(52.30 g), and the mass of three iron nails(2.73 g). The goal of this experiment is to determine the number of moles of copper and iron that would be produced in the reaction of iron and copper(II) chloride, the ratio of moles of iron to moles of copper, and the percent yield of copper produced. 2.00 grams of copper(II) chloride was added in the beaker to mix with 15 mL of distilled water. Then, three dry nails are placed in the copper(II) chloride solution for approximately 25 minutes. The three nails have to be scraped clean by sandpaper to make the surface of the nail shiny; if the nails are not clean, then some unknown substances might accidentally mix into the reaction and cause variations of the result.
A hydrate is a compound, where water molecules are chemically bounded to another compound or element. An anhydrate is the substance remaining after removing water from a hydrate. The hydrate in this lab was Copper Sulfate. The hydrates formula is CuSO4 times xH2O. The purpose of this lab was to pull the water from a hydrate to expose the anhydrate and calculate what the hydrate is by finding the formula for the
This finding could have been due to experimental errors which affected the results. Discussion
First, two grams on an unknown white compound were given. The possible compounds the known could be were CaCO3, KNO3, NH4Cl, CaCl2, K2SO4, (NH4)2SO2, Ca(NO3)2, NaC2H2O2, K2CO3, MgCl2, Na2CO3, 0.1 M AgNO3, MgSO4, NaCl, 0.2 M BaCl2, KCl, NaSO4, Mg(s), HCl, HNO3, NaOH, HC2H3O2, H2SO4, and KOH. The solubility test required using a scale to measure .575 of our unknown white compound. The unknown compound was measured in a 100 mL beaker.
The results do not support the hypothesis that a higher surface area to volume ratio would result in sulphuric acid being diffused into the agar cubes in the shortest amount of time. This is evident in the results as the exact opposite to what was predicted occurred. Instead of the smallest cube with the largest surface area to volume ratio of 1cm3 having the quickest diffusion rate, it conversely took the longest at 0.092 cm3 per second, whilst the 2cm3 cube with 0.0384 cm3 per second took the least amount of time. This directly refutes the hypothesis. There was also no consistent trend evident in the results.
Firstly, because the NaHCO3 compound was not stored in a sealed container, therefore dust particles could have changed the results, and making the product impure. Also, there are uncertainties associated with the instruments used in this experiment. This, if the products were measured slightly more than should be, this could have affected the concentrations of the solutions, and therefore causing a larger
The actual data is the result on our experiment vs theoretical, which is based on the calculations above. I have also learned to pay more attention to draining out all of the product completely before continuing to test the experiment, as any small drop of contaminant can veer our results into a different
The % yield was greater than 100% because the actual yield was greater than the theoretical yield. One error that may have caused this result to occur was that the copper may have not completely dried over the time it was left. If water was still inside the copper, it would increase the mass of the actual yield. If the copper was left in the beaker to dry for a longer time, it would help decrease the mass of the copper (as the water would be completely dried out) and bring the actual yield down.
In this experiment, the amount of water lost in the 0.99 gram sample of hydrated salt was 0.35 grams, meaning that 35.4% of the salt’s mass was water. The unknown salt’s percent water is closest to that of Copper (II) Sulfate Pentahydrate, or CuSO4 ⋅ 5H2O. The percent error from the accepted percent water in CuSO4 ⋅ 5H2O is 1.67%, since the calculated value came out to be 0.6 less than the accepted value of 36.0%.This lab may have had some issues or sources of error, including the possibility of insufficient heating, meaning that some water may not have evaporated, that the scale was uncalibrated, or that the evaporating dish was still hot while being measured. This would have resulted in convection currents pushing up on the plate and making it seem lighter by lifting it up
The chemical equation for this experiment is hydrochloric acid + sodium thiosulphate + deionised water (ranging from 25ml to 0ml in 5ml intervals) sodium chloride + deionised water (ranging from 25ml to 0ml in 5ml intervals) + sulphur dioxide + sulphur. As a scientific equation, this would be written out as, NA2S2O3 + 2HCL + H2O (ranging from 25ml to 0ml in