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Density Of Sprite

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Category: Science

Autor: reviewessays 22 February 2011

Words: 1555 | Pages: 7

Hamza Aziz

General Chemistry I Lab

09/12/2007

Lab 7

Density of Sprite and Diet Sprite

Abstract:

The density of regular Sprite was found to be 1.037 +/- g/mL. compared to Diet Sprite which was 0.9965 +/- g/mL. Among the three volumetric glassware Pipette was most precise (у=0.0016 g/mL). Burette was the second best (у=0.0023 g/mL) and graduated cylinder was the least precise (у= 0.007 g/mL). Density was found to be intensive property. The slope of the graph of mass against volume was 1.05 g/mL, with the best linear fit for the data.

Introduction:

In chemistry, accuracy and precision are very important. Accuracy is the degree of conformity of a literature value and precision is a degree to which further calculated values show similar result. In this lab, the volume of the solution (diet or regular) is measured using the Pipette, Burette, and Graduated Cylinder respectively. The mass of the solution is then measured to calculate the density of the soda. Density is mass of a substance per unit volume2. How heavy the substance is according to its size or volume. The volume of liquid is measured in mL and mass in grams. Since, the density of water is 1g/cm3 ; therefore Diet Sprite’s density should be equal to or a little bit more then water. The hypothesis was that regular Sprite will have higher density because it has a higher sugar concentration present which increases the mass per volume ratio of the solution. In this experiment only regular Sprite was used. The results are then compared to another group which calculated the density of Diet Sprite.

Experimental:

Part A

In the first phase of the experiment, the 25 ml Pipette is used to measure the volume and mass of the solution. Another beaker was in grams. Pipette was used to measure 25ml of regular Sprite. The solution was drawn the beaker and its mass was measured on the electronic balance. Mass of the solution was then calculated by subtracting beaker’s weight and beaker with solution’s weight. When 25ml solution’s mass was known, its density was calculated by dividing mass by its volume. The steps were repeated once again to get the precision of the glassware.

In the next step, Burette was used to measure 25ml solution. The mass of empty beaker was measured. Burette was used to measure 25ml of solution and then it was drawn into the beaker. After that the mass of the beaker with solution in it was measured. Beaker’s mass and beaker with solution’s mass were subtracted to get the solutions mass. The density of the solution was calculated by dividing the mass by volume. This part was performed once more to get the average density of the two trials.

In the last step of the first part, a graduated cylinder was used to find the density of the solution. An empty Graduated Cylinder’s mass was measured on the weighing balance. Then, the cylinder was filled with solution up to 25ml mark. Mass of the solution was calculated by subtracting the mass of the cylinder and cylinder with solution in it. The density was calculated by dividing mass by 25ml volume.

Same methods were used to perform this experiment one more time. The measurements and densities from this experiment can be found in Table 1. Figure 1 shows the graph and data collected from all three of the labs on Tuesday, Wednesday, and Thursday.

Part B

This time only burette was used to calculate the density of five different volumes: 5ml, 10ml, 15ml, 20ml, and 25ml because it was found to be the easiest and quickest glassware among the three to use. The weight of an empty beaker was measured which was 50.540 g. 5ml of Sprite was carefully measured in burette and was drawn into the beaker. Beaker’s weight with solution in it was measured. After that another 5ml solution was added and weight was measured on electronic balance. The process was repeated by adding 5ml to the solution until the volume reached 25ml. Mass of the beaker with solution was subtract to the mass of beaker every time 5ml were added to the solution to get the mass of the solution by itself. Densities were calculated and graph was plotted of the whole experiment. Table 2 shows the results of the experiments. Figure 2 shows the densities measured in this experiment.

Results and Discussion

Table 1

The standard deviation of the densities calculated from three different volumetric glassware can be calculated through following equation1:

Where N stands for number of trials and x is the density.

Table 1

Pipette Burette Graduated Cylinder

Trial 1 Trial 2 Trial 1 Trial 2 Trial 1 Trial 2

Mass of container 50.781 g 50.461 g 59.707 g 59.701 g 88.883 g 88.884 g

Beaker w/ soda mass 76.630 g 76.410 g 84.435 g 85.601 g 114.26 g 114.35 g

Mass of soda 25.849 g 25.949 g 24.728 g 25.900 g 25.383 g 25.473 g

Volume of soda 24.99 ml 25.01 ml 24.85 ml 24.9 ml 24.9 ml 25 ml

Density 1.034g/ml 1.037g/ml 0.9951g/ml 1.040g/ml 1.02g/ml 1.01g/ml

Mean Density (g/ml) 1.035 1.018 1.02

Standard Deviation 0.0016 0.0023 0.007

Figure 1: Shows the density of Sprite and Diet Sprite calculated through three volumetric glassware.

Table 1 shows the results from Part A of the experiment.

According to these calculations pipette turned out to be the most precise since it has the least standard deviation of 0.0016. Figure 1 shows the pooled data of Sprite and Diet Sprite from both groups. It illustrates that pipette is the most precise because the density values are the closest to each other than any other glassware.

The results showed that regular Sprite was denser than Diet Sprite because of the sugar molecules present in the solution made it heavier. As Figure 1 illustrates, that the Diet Sprite’s density is around 1g/ml which is the density of water. The variation of data on the graph may be the result of systematic or random errors. In this experiment, volume is the independent variable which affected the mass calculated by the weighing balance. Figure 1 also pointed out the precision of the three glassware used to measure the volume. Pipette seemed to be the most precise instrument to use for measuring volume because most of the Diet Sprite and all of the regular Sprite densities were calculated very closely. Burette was also accurate but not as precise as pipette. There are some points on burette chart that go very high or very low. This is probably because the volume was not measured accurately. Another error that altered the data was the beaker used to measure the mass might have some solution in it already and thus mass of the solution increased. Mistakes such as wrong measurement or calculations also affected the graph. Pipette is the most precise because almost all the points are close to each other whereas graduated cylinder is the least precise because the data is vastly spread on the graph 1.

Figure 1: shows measurements of Diet and regular Sprite with three different volumetric glassware

The % error for regular sprite for three kinds of volumetric glassware was calculated using the group data of regular Sprite from all three labs on Tuesday, Wednesday, and Thursday by getting the average and subtracting it from the average of resulted densities in this experiment. The graph is added at the end of the report as Figure 3. The densities can be found in Table 1. The results are as follows:

Pipette: [(1.035-1.044)/1.044] x 100% = 0.862 %

Burette: [(1.018-1.063)/1.063] x 100% = 4.5%

Cylinder: [(1.02-0.961)/0.961] x 100% = 6.14%

After looking at the percentage error, Pipette has the least percentage thus making it the most accurate. Cylinder has the highest percentage error which shows that it is the least accurate.

In Part B of the experiment the densities did not increase as mass and volume increased. Table 2 shows densities calculated using a Burette. Densities were precise when volume was calculated through burette. Figure 2 shows the results and Table 2 presents the data of measurements of mass and volume. Density is an intensive property because the mass and volume of the solution did not affect the density2.

Table 2

Volume (ml) Beaker & soda mass Mass of soda Density

5.00 55.680g 5.140g 1.028 g/ml

10.00 60.825g 10.285g 1.029 g/ml

15.00 66.046g 15.506g 1.034 g/ml

20.00 71.383g 20.843g 1.042 g/ml

25.00 76.583g 26.043g 1.042 g/ml

The slope (Density) is a straight line suggesting that mass and volume do not have a direct effect on the density. As mass increased, volume increased but density remained almost the same proving that density is an intensive property. Figure 2: Density of Sprite measured through burette only

Conclusions:

The main purpose of this experiment was to calculate the density of Sprite and regular Sprite; by measuring 25 ml of soda in three different kinds of volumetric glassware and see which one is the most accurate and precise. The data proved that pipette is the most precise and accurate among all three since it had the lowest percentage error and standard deviation. The densities of Diet Sprite and regular Sprite have measurable differences as shown by Figure 1 and Table 1. Theoretically, the density of diet sprite was less than regular sprite because it contains less sugar molecules. The theory was proved right that regular Sprite was denser in this experiment. We cannot be sure if it was because of the sugar molecules because the amount of sugars was not calculated in this experiment. The density, as shown in Figure 2, is the intensive property because it did not change even after mass and volumes were increased.

References

1. “Standard Deviation” Wikipedia 2007. 2 octuber 2007

2. Chemistry, 9e, Raymond Chang, McGraw-Hill, New York, p. 15, 2007.