science homework
- Locked due to inactivity on Aug 4, '16 4:17pm
Thread Topic: science homework
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James Richason
Popcorn Comparison
Chemistry
Period 7
Mrs. Lang
9/24/11
A comparison of three types of popcorn brands
Introduction
How popcorn pops:
Popcorn kernels contain oil and water with starch, surrounded by a hard and strong outer coating. When popcorn is heated, the water inside the kernel tries to expand into steam, but it cant escape through the popcorn hull. The hot oil and steam change the starch inside the popcorn kernel, making it softer. The popcorn reaches a temperature of 180 °C, which is enough pressure to rupture the popcorn hull, turning the kernel inside-out. The pressure inside the kernel is released very quickly, expanding the proteins and starch inside the popcorn kernel into a foam, which cools and sets into the familiar popcorn puff.
Purpose:
The purpose of this experiment was to determine if the price of the product made a difference in the quantity or the quality of the popcorn.
Hypothesis:
Under the same heating conditions, the higher price popcorn should have a higher quantity and quality than the lower price popcorn.
Procedures:
1. Measure the mass of a 250 mL beaker, record the mass in your date table.
2. Add a small amount of vegetable oil to the beaker to coat the bottom of it. Measure the mass of the beaker and oil. Record the mass in your data table.
3. Add 20 kernels of brand A popcorn to the beaker, shake the beaker gently to cat the kernels with oil. Measure the mass of the beaker oil, and popcorn. Record the mass in your data table.
4. Subtract the mass found in step 3 to obtain the mass of 20 un-popped kernels. Record the mass in your data table.
5. Cover the beaker loosely with the aluminum foil. Punch a few small holes in the aluminum fill to let moisture escape. These holes should not be large enough to let the popcorn pass through.
6. Heat the popcorn until the majority of the kernels have popped. The popcorn pops more efficiently if the beaker is held firmly with tongs and gently shaken side to side on the wire gauze.
7. Remove the aluminum foil from the beaker and allow the beaker to cool for 10 minutes. Then, measure the mass of the beaker, oil, and popped corn. Record the mass in your data table.
8. Subtract the mass in step 7 from the mass in step 3 to obtain the mass of water that escapes when the corn popped. Record the mass in your data table.
9. Calculate the percentage of water in the popcorn.\dispose of the popcorn.
10. Dispose of the popcorn in the designated container. Remove the aluminum foil. And set it aside. Clean the beaker, and dry it well. Alternatively, if your teacher approves, use a different 250 mL beaker.
11. Repeat steps 1-10 for brand B popcorn.
12. Repeat steps 1-10 for brand C popcorn.
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