Is The Percentage Of Water In 1.5 Grams Of Copper Sulfate Hydrate

This experiment is based on determining the chemical formula for a hydrated compound containing copper, chloride, and water molecules in the crystal structure of the solid compound, using law of definite proportion. The general formula of the compound is CuxCly•zH2O, and aim is to determine chemical formula of this compound.

This produces a 106% error causing a very large range of possible values causing our results to be very imprecise.

The purpose of this lab was to determine the percent cobalt and oxalate by mass, and with that information, the empirical formula for cobalt oxalate hydrate, using the general formula Coa(C2O4)b.cH2O.

The mass of the water was found by subtracting the original mass of the hydrate by the anhydride, that was found after heating the hydrate and evaporating the water. However, if the hydrate was not fully heating and there was still excess water remaining, this excess water mass would be included in the anhydride mass. This would make the mass of the anhydride larger and the mass of the water smaller. If the mass of the water was smaller, then the amount of moles of water would also be smaller. The mole ratio of anhydride to water would be larger because the denominator in the ratio, water in this case, would be smaller, so the entire ratio would essentially increase. This would mean that the number of molecules of water would be smaller as a result.

The results did not correlate with the pre-lab prediction as

The goal of this experiment was to determine the empirical formula for a hydrate of magnesium sulfate and water. The technique that was used was measure the mass of the hydrate and then apply heat to evaporate the water. Then determine the mass of water that was in the hydrate and the mass of the remaining magnesium sulfate. The equation for the hydrate is determined by calculating the mole to mole ratio of the water and the anhydrous. The resulting formula will be formated as: MgSO4*_H2O

The mass percent of water was determined using the mass of water and dividing it by the total mass of the hydrate and then multiplying that answer by 100%. The number of moles of water in a hydrate was determined by taking the mass of the water released and dividing it by the molar mass of water. The number of moles of water and the number of moles of the hydrate was used to calculate the ratio of moles of water to moles of the sample. This ratio was then used to write the new and balanced equation of the dehydration process. The sample was then rehydrated to the original state and the percent of the hydrate recovered was calculated by using the mass of the rehydrated sample by

b) Possible reasons for the difference between our value and the literature value could be the fact that the machine we used would have absorbed some of the load, the dials and other measuring tools were difficult to get a very accurate reading from and how the experiment was set up on our behalf.

After this, the solution was poured into a volumetric flask just about to the 1dm3 line and then it was left there to cool to the same temperature as the room before filling precisely to the 1dm3 line with distilled water. The molar mass of CuSO4.5H20 was 249.5 so that means 249.5g of copper sulphate was needed to dissolve, in order to make a standard solution, into 1dm3of distilled water. Following this, a linear dilution of the CuSO4.5H2O was made in order to be used to make a calibration curve after using the colorimeter to write down the absorbance of each sample. A linear dilution is diluted with distilled water in order for it to make the concentration weaker and weaker. For this investigation, the dilutions made ranged from 0.01 to 0.1 M/l . It was essential to only make up 10cm3

These values are incorrect for the experiment due to the negative slope. A negative slope may have been obtained due to inaccurate make-up of the original solution, possibly an error in calculation but this shows that extreme attention to detail is required throughout all aspect of experiments. A positive result for a Lineweaver-Burk plot has been included for

While that does mean there was some error, it shows that there was not a large amount of it. There are multiple sources for error in this lab. One of these being human error. More specifically, the group not measuring to the exact spot. Meaning that the measurements could be a tiny bit off, because no one

There maybe some errors in my method with people understanding my explanation on how to do the experiment because the instructions may be interpreted differently. In my

The results clearly show the limitations of purely theoretical and purely experimental analysis due to the range of

From this we can argue that the errors I had during this experiment were not very big, and did not affect my results too much. My result supports my

After the experiment was concluded, my theory was correct, the eidetic technique scored 100% both times.