What Conditions to Keep Chips in Overnight

Background Information.

I think that this practical will be based on osmosis because ,Osmosis is the random movement of water molecules from a high concentration to a low concentration . This will then happen between the chips and the liquid in the McCarthy bottles . This already tells us that the chips will vary in size from the concentration of water .

Plan of the Experiment.

Method

1

Firstly we shall set up the experiments by getting the apparatus and the materials (potatoes) ready. We shall then get the 18 McCarthy bottles needed . Then put them on the desk ready for the potatoes to be added when ever.

We should then get the weighing scales and the core remover, along with a ruler on the side.

2

Secondly we should core the potatoes and then accurately weigh, and measure them. To measure them we should use a scalpel and a ruler the scalpel should then be used to accurately cut the pieces of potato, the potatoes should all be cut with the same corer to ensure a fair test. To make the cutting even more accurate we should use a square so that the potato is accurately cut.

We should also then weigh them accurately so that we will be able to find out the difference after. We should record these results.

3

Also, we should then start to add the liquids to the cylinders , We should then add all the potatoes at roughly the same time after they are all full. We shall then record these details and use them so that when we take them out it will be exactly the right time each. For the test to be as accurate as possible my nights will be until lunchtime the next day, so we can find out exactly which one is the best .

4

Finally when we take them out of the cylinders we should then put them straight onto the weighing scales to find out what the results are. We will then record them to find out the results.

Preliminary Work

I think that the preliminary work I have completed has helped tremendously with the practical experiment.

The work on osmosis has helped with understanding and helping to put together this experiment .

Factor

In this experiment the factor we will vary will be the S.S.S , this will be the molar amount in the liquid . We are going to use ;

0 molar (distilled water)

0.1 Molar

0.2 Molar

0.4 Molar

0.6 Molar

0.8 Molar

This will mean that in group 0.8molar the S.S.S will be the strongest and in 0molar there will be nothing except for water (distilled).

Hypothesis

Mass gain or loss.

I think that out of the samples if you think in a simple part of osmosis I think it would be relatively easy to predict which ones would gain or lose mass starting with , In pure water the chips will be predicted to put on loads of weight , this is because ther will be a lower concentration inside the chip than outside .

I predict that in group 2 & 3 there will be the most loss in weight because the chip will have a higher concentration than the water around it . This is because of the solution in the water.

Trend in gains of mass

The mass of the chip will vary , but if the concentration of the chip is lower than the outside then there will be more concentration outside meaning that the water molecules will try to get to the lower concentration inside the chip causing it to expand in size and mass.

I think the samples I believe that will lose the most mass will be the 4m & 6m because they will have a lower concentration than the chip and the water molecules from the chip will come out and it will lose mass .

Trend in loss of mass

The trend in loss of mass is virtually the opposite to the gain in mass. It works that if there is less concentration outside the chip then the water molecules from the chip will then come out, causing a loss in mass.

Prediction of the approximate value

I believe that the approximate value of the solution that is equal to the chips is somewhere between .4 to .6 because it would equal up the liquid and the water making it equal helping it to not gain or lose much mass.

Plan

Apparatus

We will use a number of apparatus including;

Tile (used to cut the potatoes on) ,

Measuring Cylinders,

McCartney bottles,

Scalpel,

Apple Core Remover,

Weighing scale.

We will also need , a potato , and the 6 solutions.

Method

1

Firstly we shall set up the experiments by getting the apparatus and the materials (potatoes and the 6 solutions) ready. We shall get the 18 McCarthy bottles, to put the groups into. There will be 3 in a group (e.g. group 1,a,b,c) We should then get the weighing scales and the core remover (we will use this to get the exact size in diameter of the potato), along with a ruler and a tile, with a marker mark out 3cm onto the tile so that we can then work out quickly the size of the chip. The size should be 3cm by the circumference of the corer.

2

Secondly we should core the potatoes and then accurately weigh (we will weigh them to 2 decimal places e.g. 1.34 grams), and measure them. To measure them we should use a scalpel and a ruler. The scalpel should then be used to accurately cut the pieces of potato, the potatoes should all be cut with the same corer to ensure a fair test. To make the cutting even more accurate we should use a marker to put a line 3cm long onto the piece of tile.

We should also then weigh them accurately so that we will be able to find out the difference after. We should record these results into a