mass of unpopped popcorn
The mass of the unpopped popcorn in the numerator was the mass of the kernels before they were popped added to the beaker, foil, and oil. The mass of the popped popcorn was the mass of the popped kernels added to the beaker, foil, and oil. The mass of unpopped popcorn in the denominator was the actual mass of the unpopped kernels massed alone. The beta kernels hold 11.1%, 11.3%, and 10.9% water for trials 1, 2, and 3 respectively. The gamma kernels are composed of 16.7%, 15.7%, and 14.8% water, while the delta kernels contain 19.4%, 17.0%, 19.0% water for trials 1, 2, and 3 respectively. (Refer to appendix for original data and calculations).
See Table 1 – Percentage of Water in Popcorn Beta, Gamma, and Delta
The data for beta was the most precise among the three different techniques. The data for delta fluctuated the most and was the least precise. According to my data, the delta kernels had the highest percentage of water and the beta kernels had the lowest percentage of water. The gamma brand was in between the two. In my qualitative observations, I observed that the gamma kernels popped the fastest, smoothly, and produced the largest popcorn. I observed that the delta kernels produced the medium-sized popcorn, and the beta kernels tended to burn very easily and produced the smallest popcorn. Basically, the beta brand of kernels was the worst popping popcorn, while the gamma brand of kernels produced the best popping popcorn. These results convey that too little water within kernels make bad popcorn, and too much water produces just medium-sized popcorn. From the overall calculations and averages, it can be concluded that 15-16% water in a kernel produces the best popcorn.
To find the theoretical amount of water in the popcorn, the most accurate data of the class were added together and averaged. When compared to the class average, the average of my data was rather accurate. To find the percent error, this formula was used:
Percent Error = ׀ theoretical value – actual value ׀ × 100
Theoretical value
My percent error for beta, gamma, and delta kernels was 0.90%, 4.46%, and 13.5% respectively. (See calculations in appendix)
See Table 2 – Percent Error
This percent error could have occurred while massing. Since there were several balanced used instead of just one, the masses could have differed. One balance was used for the kernels, while the beaker mass was found using a separate balance. The different balances could have lowered the accuracy of the masses. Another place where mass could have been inaccurate was when the popcorn was popped. Sometimes the popcorn was burned, while other times the popcorn was popped perfectly. If the popcorn was burnt, the mass was lowered by the release of CO2. Also, the duration of the heating of the popcorn was inconsistent. Since the popcorn of the same technique would still pop at different rates, it is impossible to control the time of the heating. But the longer the beaker is heated, the longer the oil inside is also heated and evaporating. So the longer the beaker is heated, the more gas escapes and the lower the mass will be, which will increase the percentage of water in the popcorn. Also, while the beakers were cooling off, some of the moisture could have been collected back in the beaker since the foil was not always taken off immediately. This would have added to the mass and lowered the percentage of water. To improve this lab, only one lab balance should be used during the entire experiment. Also, more care should be exercised when popping popcorn so that the popcorn does not burn. This could be done by lowering the heat and shaking the popcorn inside the beaker. Also, the foil on the beaker should be removed immediately after heating.
In this lab, I discovered that more water in a kernel does not necessarily mean that it will produce larger popcorn, as I had initially had predicted. Ultimately, based on my data and the class average (theoretical value) 15-16% water in a kernel produces the best popcorn. I learned that the amount of water in the kernel affects the rate at which the kernel pops, more than it affects the size of the popped corn.
Figure 1 – Setup Diagram
Table 1 – Percentage of Water in Popcorn Beta, Gamma, and Delta
Table 2 – Percent Error
Original Data:
Trial 1 Mass of Kernels (±0.001 g) and Observations
Trial 2 Mass of Kernels (±0.001 g) and Observations
Trial 3 Mass of Kernels (±0.001 g) and Observations
Calculations:
mass of unpopped popcorn – mass of popped popcorn ×100 = % of water in unpopped popcorn
mass of unpopped popcorn
Trial 1: Beta: % water = 118.002g – 117.626g × 100 = 11.1%
3.383g
Gamma: % water = 112.277g – 111.690g × 100 = 16.7%
3.506g
Delta: % water = 115.003g – 114.188g × 100 = 19.4%
4.210g
Trial 2: Beta: % water = 114.276g – 113.897g × 100 = 11.3%
3.354g
Gamma: % water = 98.892g – 98.319g × 100 = 15.7%
3.661g
Delta: % water = 108.995g – 108.312g × 100 = 17.0%
4.018g
Trial 3: Beta: % water = 118.417g – 118.050g × 100 = 10.9%
3.364g
Gamma: % water = 113.031g – 112.493g × 100 = 14.8%
3.633g
Delta: % water = 113.782g – 113.062g × 100 = 19.0%
3.781g
Percent Error = ׀ theoretical value – actual value ׀ × 100
Theoretical value
Beta: Gamma:
׀11.1% – 11.0% ׀ × 100 = 0.900% ׀15.7% - 15.0% ׀ × 100 = 4.46%
11.1%% 15.7%
Delta:
׀18.5% - 21.0% ׀ = 13.5%
18.5%