What factors affect dissolving.

If the water is at a higher temperature, the water molecules will be moving more quickly. The collisions with the sugar molecules will be more often and each collision will be faster. Therefore the process of dissolving will be faster.

Variables:

Controlled:

In my experiment, I will keep these things the same to make it a fair test.

• The moving of water
• The volume of water
• The mass of sweets
• The type of sweets
• The surface areas of sweets

I will change the temperature of water by heating it with a Bunsen burner and measure the temperature with a thermometer.

I will measure and record …

I will measure and record the time it takes for the sweets to dissolve. We know it’s dissolved when the sweets can’t be seen and when the water has changed colour.

Reliable test:

I will make sure that it is a reliable test by repeating the experiment at least 2 times and calculating the average result and measuring accurately.

Apparatus:

In this experiment, I am going to use the following apparatus:

• Stop Clock
• Beaker
• Measuring cylinder
• Thermometer
• Bunsen burner

Diagram:

This is a diagram showing how the experiment is done.

Method:

I am using this method to do my experiment.

1. Set up the apparatus as shown above.
2. Put the beaker of water on the safety mat and light the Bunsen burner. Put goggles on for safety.
3. Heat it to a certain temperature and measure it with a thermometer to make sure it is accurate.
4. Put off the Bunsen burner or put it away from the beaker
5. Drop the sweet into the water and stir regularly.
6. Keep checking the temperature of the water to see if it is still the required temperature. If not, heat it with the Bunsen burner.
7. Record the time it takes to dissolve the sugar
8. Repeat the experiment as least 2 times to make it a more reliable test.

Results Table:

Table showing how temperature affects the speed of sugar

dissolving in water.

Analysis:

Graph:

From the graph above, we can see that as the temperature of the water increases, so does the speed of dissolving. The results agree with my prediction in which I said the sweets are going to dissolve quicker if you increase the temperature. This happens because as the water molecules are heated up, they move faster: which causes more collisions with the sugar molecules of the sweets. The sugar molecules dissolve much quicker with heated up water molecules than the cooled down ones.

Evaluating:

This experiment was kept a fair test because all the variables or factors were controlled except for one – the temperature of the water. Most of the results fit into the line of best fit but some do not. This is due to the reliability of the test. A few things could be improved in order to make it a more accurate and reliable experiment.

E.g.:

• Measure the water with a measuring cylinder before pouring into the beaker
• Check on the temperature more often to make sure it is the same temperature throughout the experiment
• Count the number of stirs and make sure it is the same every time
• Measure the temperature and time more accurately.

There are a few other investigations I could have done:

• The moving of water ( number of stirs )
• The volume of water
• The surface area of sweets
• The mass of sweets
• The type of sweets.