Experiment -Effects on the temperature of snow when you add salt

II) Aim: 

To determine how the amount of salts affects the temperature of a slushy mixture of salt and snow.

III) Variables:

The independent variable is the quantity of salt in g. The dependent variable is the change of temperature in °C. The constant is quantity of snow in g.

IV) Method:

• Collect some clean snow in a basin.
• Weight out 25 grams of snows in a small insulated beaker.
• Weight out 1 gram of salt (sodium chloride) in a white weighting boat.
• Add the salt to the snow, stir the slushy mixture gently with red alcohol thermometer and take the temperature when it has stabilised (doesn’t change any more). Record the value.
• Clean out the beaker into the sink.
• Repeat the experiment a further 5 times but using instead 4, 2, 1.5, 0.5 and 0 grams of salt. Keep all other variables the same.
• Record and display your results in an appropriate fashion

V) Results: how the quantity of temperature affects the temperature. 

VI) Conclusion:

The table of results shows that when you had salt the temperature decreases. As the graph shows, the temperature change depends on the quantity of salt added.

The salt added is sodium chloride, NaCl. When you add that salt to snow it makes ice mixture (SaH). The melting point of the snow becomes lower as more particles are added until the point where the salt stops dissolving. Normally the sodium chloride can melt ice only down to about -9°C.

VII) Evaluation:

I think that the method is fine. However it could have been better if the starting temperature of the experiment would have been the same. To improve the result we could have redone the experiment for each quantity of salt to be sure that the results are relevant and we could have done more different quantity, as 2.5, 3, 3.5 or 5.

VIII) References: