An experiment to see how much sugar can be dissolved in different volumes of water

To set up my experiment first I will set up my scales I will then measure how much the beaker I am using to hold the water weighs, I will then zero the scales and add the water to the desired volume (weight).  I will then do the same with the sugar; first I will weigh the measuring cups (that I will use to hold the sugar in before I add it to the water) then I will zero the scales and then measure out the sugar to 10 grams in each measuring cup.  I am doing it at this amount because then I have a greater scale to work with and from my preliminary testing I found that adding greater amounts meant that I couldn’t tell when the sugar really stopped Dissolving, doing it at this amount ensures I am able to.  I will then start to add the sugar 10 grams at a time and I will stir it until the sugar is completely dissolved, I will also time it with a stopwatch for the sugar to completely dissolve.  I will then another 10 grams and will time that while stirring it until the sugar is completely dissolved, I will repeat this process of adding more sugar and timing it to dissolve until it stops dissolving, will then note this on my table.  Then I will change the volume of water by weighing the beaker, zeroing the scales and then adding the required volume of water then I will repeat the experiment by adding the sugar and timing its time to dissolve until the sugar stops dissolving.  I will repeat the experiment 6 times in total, each time I will only change the volume of water and noting when the sugar stops dissolving in the water.        

Results

Analysis

From my experiments I can see that, as the volume of water is increased so to is the volume or weight of the sugar increased with it.  This is because there are more water molecules (randomly moving about) and so there are more spaces between the water molecules as they move around for the sugar molecules to dissolve into.  I have also noticed that the amount of sugar that I can dissolve is in proportion to the water with a ratio of about 1:1.2 this is reflected in my tables above, after that the sugar stops dissolving and is left at the bottom of the glass.  I have also recorded the time that it took for each 10gram amount of sugar to completely dissolve into the water. From the tables above I can see that as the as more sugar is added the time that it takes the sugar to dissolve increases each time this is shown in my graphs, and when it is getting near the end it starts to take quite a long time to dissolve.  This is because as more and more sugar is added there becomes less and less spaces for the sugar to dissolve into and so it takes longer and longer for the sugar molecules to dissolve into the water.

Evaluation

Overall I think that my experiment was a complete success as the things I predicted were all proved correct.  There were a few things I could have changed and also a few things that I noticed over the course of the experiment.  If I was going to the experiment again I could reduce the amount of sugar that I added each time to 2 or 5grams, by doing this I could I could get a more precise result and would be able to pinpoint exactly at what amount that the sugar stopped dissolving.  I could also decrease the amount that the water was increased by to 25ml instead of 50ml, by doing this I could find out for definite if the proportionate ratio of 1:1.2 between the water and the sugar was correct up to 300ml.

Over the course of the experiment I took some temperature measurements with a precise digital thermometer at the start and at the end of the experiment.  Throughout the day when I was retrieving the water from the tap and then taking its temperature its started to rise, this could have been because of warmth from the sun and warmth from the central heating warming the water pipes through the day.  During the test however I noticed that the warmer water dissolved the sugar faster than the colder, the water was only warmer by a couple of Celsius but it was still noticeable.  This could be because with the water being warmer it made the water molecules move around faster and bang into the sugar particles breaking them up and then carrying them away and spreading them around the solution of course to be absolutely sure of this I would have to do further testing.  

I also noticed that the sugar I was using was granulated and that all the smaller pieces of granulated sugar had fallen to the bottom and that all the larger pieces were on the top.  Through the course of my test I used all the larger pieces and then when I got to the bottom I used them as well I measured them out to the same weight of 10 grams and then poured them into the water and stirred until they dissolved, I noticed that the time that it took for the smaller granules of granulated sugar to dissolve was quicker than the time it took for the larger granules to dissolve.  This could be just a radical result but I do not think so, my theory is that because the sugar is in smaller pieces there is a greater surface area and so the water molecules dissolve the sugar faster because there is more places for it to knock into the sugar and break off a molecule and carry it away throughout the solution.  I think that extra results need to be done with different types of sugar such as icing, caster, granulated and cubes to prove this.