After leaving in the oven for several days:
Data Analysis:
Out of 28.80 g of Camembert, 15.81 g is water. That is:
15.81 / 0.288 = 54.9%
Criticism:
Our results can be easily criticized since they are very approximate. The first reason that can explain any erroneous results is the fact that the more fresh the cheese is the more it contains water. Our cheese was not very fresh therefore it might of had more than 15.81g of water. Also, while in the oven at 50 oC, more than just water might of evaporated. When doing this experiment keep the cheese in the oven until no further changes in mass occur and make sure your cheese is as fresh as possible.
Finding the enthalpy change of Camembert:
Materials: deflagrating spoon, small piece of Camembert, balance, Bunsen burner, matches, electronic thermometer, test tube, water, retort stand and clamp.
Method:
- Fill the test tube with 25 g of water and then mount it on the retort stand. Put the thermometer in the water wait until the temperature stays at a fixed position. Note the temperature of the water.
- Zero the balance and weigh the deflagrating spoon. Weigh it again with the piece of cheese and then find the mass of cheese by subtraction.
- Light the Bunsen burner and heat the cheese from underneath the spoon.
- Slightly turn the spoon so that the flame touches the cheese allowing it to catch on fire.
- Once the cheese is properly burning, place it under the test tube and leave it until the cheese stops burning.
- Note the maximum temperature reached by the water.
- Find the temperature change.
Results:
Data Analysis:
ΔH = c x m x ΔT
ΔH → enthalpy change
ΔT → temperature change
c → specific heat capacity of H2O
m → mass of H2O
We used 25g of water (m = 25) and heated it with 3.02g of cheese which created the heat change of 11.2o from the initial value of 27.8oC (ΔT = 11.2) and we know that the heat capacity of water is 4.18, therefore:
ΔH = 4.18 x 25 x 11.2
ΔH = 1170.4 J.g-1
This means that 1 g of cheese produces 1170.4 J of energy. Which means that 100 g of Camembert produces 117 040 J of energy.
Taking in account that a human of 70 kg needs 12 500 000 J of energy per day:
(12 500 000 / 117 040) x 100 = 10 680.11
One can easily calculate, as shown above, that the human need to eat 10 680.11 g of Camembert to intake the amount of energy needed.
Comparing with other cheeses:
Criticism:
Many factors affected our results. These factors our things such as the temperature of the water was very difficult to measure since we were beside a window. Also, the cheese was hard to ignite, therefore, some energy was not measured. Therefore, make sure one is not near a window or door or any place that could affect the temp of the water and that one uses aplastic container to prevent the water temperature to change.
Separating Organic and Inorganic Components of Camembert
Material: Bowl, grill, tripod, Bunsen burner, matches, ethanol, fresh Camembert
Method:
- Weigh a bowl.
- Add a piece of fresh Camembert and weigh again. The mass of the cheese is then calculated by subtraction.
- Place the bowl containing the cheese on the grill after lighting the Bunsen burner.
- Light the cheese using the Bunsen burner.
- The cheese will become hard to keep on fire. Add ethanol once in a while to help.
- Once there is only white ash left in the bowl, weigh the bowl of ash. The mass of the ash can be calculated by subtraction.
Results:
Data Analysis:
% Organic compounds = 10.47 / 0.11 = 95.2% (1)
% Inorganic compounds = 0.53 / 0.11 = 4.8 % (2)
Criticism:
While burning, the heat of the cheese broke our bowl several times, therefore while transfering, some ashes were lost. Also because of time we did not burn the ash until it was totally white. We therefore recommend that you make sure your bowls can support a large amount of heat for a large amount of time. And that you make sure to have a lot of time ahead of you.
Chemical testing for ions in present in Camembert
Materials: Test tubes, distilled water, beakers, filter paper, Barrium chloride, potassium hexacyanoferrate (III),potassium hexacyanoferrate (II), Silver (I) nitrate, sodium hydroxide , Iron (II) sulphate solution, concentrated sulphamic acid, lead (II) ethanoate, Hydrochloric acid.
Method:
-
After doing the method for the experiment Separating Organic and Inorganic Components of Camembert, pore the ashes in a beaker and add water. Make sure it is mixed well.
- Pore the ash solution into the filter paper which lies open on a beaker.
- While waiting for the filtration, add 2 cm of water into each test tube. Then add the 1 cm of the solutions into test tubes. One solution per test tube.
- Then add some of the filtered ash solution into each of the test tubes.
- Record any observation.
Results:
Criticism:
These experiments are easy to perform. However, they are not useful when it comes to observe the amount of each ion.
