Evaporation is a type of vaporization, vaporization of a liquid but then it occurs on the surface of a liquid or boiling. Evaporation happens when molecules collide and transfer energy to each other at a certain temperature. Some liquids do not visibly evaporate but they are actually evaporating it just happens so slowly that its barely visible.
For evaporation to take place, the molecules of the liquid need to be located near the surface and moving in a certain direction. Also, they need to have enough kinetic energy to become a gas. The slower this process takes, the longer the evaporation takes. When temperatures are higher, the evaporation happens faster. When the fast-moving molecules have evaporated the leftover molecules tend to have less kinetic energy and the temperature of the liquid drops. This is the reason for sweat cooling down the body. This is also called evaporative cooling.
In the experiment we used Lays Paprika chips. The chips contain 34% fat and 0,5% sodium (salt).
Hypothesis:
Referring to the reference values, I think there is 34% fat and 0,5% salt in the Paprika chips.
Initial observations:
When we soaked the chips in water, the chips got very soggy and mushy. Also, the water turned a bit red, which we think came from the paprika flavor of the chips.
When we soaked the chips in White Spirit, the chips stayed quite crispy but did change colors. The red coloring from the paprika dissolved in with the solvent and turned it orange-reddish, leaving the chips a natural color.
Method/materials:
- Chips (1-2)
- Water (25mL)
- White spirit (25mL)
- 100 mL beaker
- Pestle
- Glass rod
- 100 mL conical flask
- Small funnel
- Filter paper 3
- Measuring cylinder (59 mL)
- Weighing scale
- Hot plate
- Bunsen burner, tripod, gauze
Procedure:
- Weigh the chips
- Put the chips in the 100 mL beaker
- Add just enough solvent * to the chips to cover them
- Stir the mixture or wait for the salt to dissolve
- Weigh the mixture
- Place a coffee cone filter in a funnel and place the funnel in the 100mL beaker
- Pour the mixture into the funnel
- Remove the funnel w/ the chips from the beaker
- Weigh the filtrate
- Evaporate the filtrate using the Bunsen Burner
- Weigh the evaporated filtrate
*Solvent are water and White Spirit
Table #1
Variables:
Results:
Raw data:
Table #2
Our data:
Our data is messed up so we decided to use the teacher’s data whilst processing.
Observations:
Whilst evaporating, the chips+ water mixture started to bubble when the temperature was raised. This means that the molecules started moving faster and started moving in random directions and colliding with each other. On the beaker condensation also formed and vapor was visible coming from the beaker. Eventually there was something burning at the bottom of the beaker, which gave a brown color. This gave a sweet smell, which later turned into the smell of burned potato. This probably means that some other substance was also in the filtrate.
Whilst evaporating the chips+ white spirit, the molecules heated up very quickly. It popped and the mixture started bubbling very violently. It quickly evaporated, much quicker than the chip+ water filtrate.
Table #3
Teacher’s data:
Table #4
Processing teacher’s data:
Calculations:
- Subtract the mass of the conical flask from the conical flask + leftovers after evaporation
- Times the answer by a hundred to get the total amount for 100 chips
Ex. 54,7g - 55g = 0,3g
0,3g x 100 = 30g
Ex. 53,4g - 53,9g = 0,4g
0,4g x 100 = 40g
Conclusion:
Referencing table #4, I conclude that in 100 chips there are 30 grams of salt and 50 grams of fat. According to the reference values on the back of the chips package, there is 0,5 grams of salt and 34 grams of fat. This means something went absolutely wrong
Evaluation:
The results from the experiment absolutely did not match the reference values on the chips packaging. This is why we decided to use the teacher’s data, which she picked randomly so it obviously can’t be compared to the real data. Our measurements were obviously not very accurate and neither was our filtering.
Bibliography:
"Evaporation." Wikipedia, the Free Encyclopedia. Web. 02 Dec. 2011. <http://en.wikipedia.org/wiki/Evaporation>.
"Filtration." Wikipedia, the Free Encyclopedia. Web. 02 Dec. 2011. <http://en.wikipedia.org/wiki/Filtration>.
