Question

Lab-Freezing point experiment:

1. How did thewater freeze when surrounded only by saltwater?

2. Describe your findings?

3 Why do you think the water in the ocean rarely freezes?

Answer 1

Fresh water freezes at 0-degree Celsius or 32 degrees Fahrenheit. When it is surrounded by salt water, the heat is absorbed by the saline water. The more is the concentration of the salt in the surrounding water, the faster is the heat absorption and the cooling of the freshwater. So, the freshwater freezes while the surrounding saltwater will remain in the liquid state.

So, adding salt to water helps to lower its freezing point. This is why salt is sprinkled on ice cubes to slow down their melting.

Ocean water contains a lot of salt dissolved in it. Ocean water does freeze, but at a lower temperature than freshwater. While freshwater freezes at 32 degrees Fahrenheit, seawater freezes at 28.4 degrees Fahrenheit. And even though seawater freezes, the ice formed contains very little or no salt because only the water part freezes. The salt from the freezing water is expelled, thus increasing the salt concentration in the water surrounding the frozen ice.