Reflection

Improving accuracy

We could have made our results more accurate if we put 2 or more eggs in each solution. Then, we measure each of the egg's final mass using an electronic scale and find the average mass loss of the eggs.

We should also have put the same amount of oil and sucrose solution to make the experiment more accurate.

Results: ( Collection of data)

1. We had intended to measure the mass of each egg before submerging in respective solutions

2. We had an interval of 1 day for the de-shelling of eggs and also for the eggs to be submerged into the different solutions. We also took the measurements a few times in case of random error and got the same measurement everytime. Thus, our results are:

Egg in oil:

[original]de-shelled: 85.5g

after putting it in oil : 77.6g

Egg in sucrose:

[original]de-shelled: 79.9g

after putting it in sucrose: 84.8g

Discussion:

We rejected our hypothesis made on sucrose. We had predicted it to lose mass but it gained mass instead. However, the hypothesis on the egg which was immersed in oil was accepted.

Explanation:

Oil:
As water molecules move from a region of higher water potential(egg cytoplasm) to a region of lower water potential ( oil ), down a water potential gradient through a partially permeable membrane by osmois, water is lost from the cytoplasm in the egg. Thus, its mass decreased.

Sucrose:

The egg cytoplasm has lower water potential than the dilute sucrose solution. As water molecules move from a region of higher concentration ( sucrose solution) to a region of lower concentration ( egg cytoplasm ), down a water potential gradient, through a partially permeable membrane by osmosis, water molecules moved into the cytoplasm causing its mass to increase.

Forming a hypothesis

When the egg is immersed in:

1. Sucrose solution

The egg would lose mass and shrink in size.

2. Oil

The egg would lose mass and shrink in size.



Variables:

Independent variables:

The temperature of the surroundings would remain constant.

The overall temperature of the solutions will be constant.

Dependent variable:

• The solution the egg is put into.

Biology Experiment ( SPA task 5)

Conducting the experiment

Apparatus:

3 large containers

Digital camera

Electronic Scale

Materials:

1 bottle of white vinegar

2 raw hen eggs

1 bottle of vegetable oil

1 bottle of sucrose solution (dilute)

Procedure:

Step 1:

Leave the 2 eggs in an empty container.

Step 2:

Slowly pour in the vinegar,enough to fully submerge the hen eggs.

Step 3:

Cover the container and leave it for 5 minutes.

Step 4:
After 5 minutes, take the cover out and observe the hen eggs in the vinegar. Bubbles should start to form about the egg.

Step 5:

Cover back the hen eggs and leave it overnight to deshell the eggs.

Step 6:
After 1 day, pour the vinegar away. Rinse the eggs with water before gently picking it up. Observe and feel the hen egg again.

Step 7:

Measure the mass of each egg and note it down. This will give you the mass of the hen eggs before putting it into respective solutions.

















Step 8:
Take another container and fill it with oil, just enough to fully submerge one hen egg. Slowly submerge the egg.

Step 9:

Take another container and fill it this time with sucrose solution. Gently submerge another de-shelled egg.

Step 10:

Close the 2 containers and leave the experiment overnight.

Step 11:

The next day, take the eggs out and gently rinse them with water.

Step 12:

Measure the mass again. Take note of any changes.