General Chemistry I Lab
Density of Sprite and Diet Sprite
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 (ó=0.0016 g/mL). Burette was the second best (ó=0.0023 g/mL) and graduated cylinder was the least precise (ó= 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:
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...