Gas Chromatographic Determination of the Ethanol Content of Potable Liquids Using the Internal Standard Method

Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.

Perform the following with three 0.05g samples of unknown and the following solvents: methanol, water and toluene

concentration was plotted in order to estimate the concentration of the unknown solution (Figure 3).

Me and my lab partner, obtained a mixture of a un known proportion from the instructor and then flow the guide line in our lab manual to separate the mixture by applying the separation method motioned in our lab manual pages 33-40 . In this experiment, the separation methods were decantation,

In this experiment, the precision of percent by mass of sodium carbonate was decent. It seemed to be consistent, although we seemed to have an outlier in our fifth trial. I believe this was due to human error of adding too much vinegar to this graduated cylinder. The accuracy of our results was decent in comparison to the rest of the class’s data, but our results were on the higher end compared to the averages of the class data, though not too high to be considered

The Beers Law calibration experiment used many concentrations of crystal violet solutions. Each of these solutions were test and analyzed in order to determine the absorbance of each concentration The results were than graphed and produced a slope of 1.00E05 with an intercept of -2.21E-02.

Each stock solution was placed in a colorimeter and was tested for it Absorbance. A computer program tested and drew up the Calibration curve/linear fit equation. However, the computer could not protect potential errors. An error for determining the concentration of the diluted and undiluted, could be a skew linear fit equation. The linear fit equation could be skewed by having an inadequate ratio of the stock solution and distilled water. For example, when making stock solution 1, 0.021(L) was used instead of 0.020(L) can throw the calibration curve, resulting a skewed linear fit equation. If the “blank” was not fully clean or had left over Allura Red residue, then the “blank” was tampered with. A tampered “blank” means any comparisons with it would have a wrong Absorbance reading. However, the most likely and most effective error, is calculation. Using the wrong V1 and V2 to determine the concentration of the undiluted would affect the answer of the grams Allura Red would be consume and the amount of molecules of Allura Red. The colorimeter is adjusted to a wavelength of 470 nm is maximize the absorbance of the Allura Red. If wavelength was place at 565 nm, then Allura Red would not absorb as much color of

was to determine the percentage by mass of acetic acid in vinegar using acid/base titration. The

The absorbance obtained from the results of each test sample, then put into the equation of calibration curve in accordance with the respective raw substances, after which it would have obtained the value of molar absorptivitas. The molar absorptivitas results obtained are used in the determination of the percentage of the sample levels

{. One drink is equivalent to 5 ounces of wine, 1.5 ounces of distilled spirits, or 12 ounces of beer

I can narrow down my unknown substance to either Ethanol or 2-proponal. Ethanol’s density is only 0.001g/mL higher than my own measurements, but its boiling point is 8.4̊C lower than GNR’s. Whereas 2-proponal’s density is off by 0.003g/mL and its boiling point is only off by 4.5̊C. If I were to make an educated guess I would lean more towards Ethanol. Both the precision and accuracy of my data was far greater in density than in boiling point and Ethanol’s density is closer to GNR’s than any other substance.

A 10 mL round-bottom flask was weighed both before and after approximately 1.5 mL of the given alcohol, 4-methyl-2-pentanol, was added. 3 mL of glacial acetic acid, one boiling chip, and 2-3 drops of concentrated sulfuric acid were added to the flask in that order. The reflux apparatus was assembled, the

A volumetric pipette & measuring cylinder can be calibrated by just weighing the water they deliver. As for volumetric flask, the weight of an empty flask is recorded. Next, weigh the flask after filling it with water to the mark.

The results that were revealed were thought to be accurate and reliable as many factors were controlled to enable the best quality. The results that a constant rise in the combustion occurred as each alcohol’s carbon chain increased with one exception indicates that the reliability of this experiment has to be examined. With such a high percentage error from these results means they cant be definitive. Also only three trials were conducted on the five different alcohols. If the experiment were to be conducted again I would conduct five trials on each alcohol to get a better average.

Moreover, NaOH cannot replace Na2CO3 for it generally do not satisfy above requirements and very hygroscopic in nature. On the other hand, 0.05 M HCl is called the standard solution. An ideal standard solution[3] is (1) sufficiently stable to determine concentration, (2) reactive with the analyte so that the time required between additions of titrant is minimized, (3) completely reactive with the analyte so that satisfactorily end points are realized, and (4) selectively reactive with the analyte that can be described by a simple balanced equation. The standardization of the titrant aims to know the exact concentration of the titrant (its deviation from the measurement done). Two basic methods are used to establish the concentration of standard solutions: (1) direct method, in which a carefully weighed quantity of a primary standard is dissolved and diluted to an exactly known volume in a volumetric flask, and (2) standardization by titrating (a) weighed quantity of a primary standard, or (b) a measured volume of another standard solution. In the