Question

A hypothetical situation of being stranded on a deserted island without water is often posed to students. A model of a process used to separate salt water into its components is shown here. Justify the use of the flame in the model depicting the separation of the mixture.

Responses

A The flame will burn the salt component of the mixture, leaving only the pure water behind for drinking. This is known as combustion.The flame will burn the salt component of the mixture, leaving only the pure water behind for drinking. This is known as combustion.

B The flame will allow the water to evaporate and be collected in its pure form, leaving the salt component behind. This is known as distillation.The flame will allow the water to evaporate and be collected in its pure form, leaving the salt component behind. This is known as distillation.


C The flame will allow the pure water and salt water to separate into different layers. This is known as density separation.The flame will allow the pure water and salt water to separate into different layers. This is known as density separation.

D The flame will sterilize the water, so that water from the ocean will be consumable. This is known as sanitation.The flame will sterilize the water, so that water from the ocean will be consumable. This is known as sanitation.

Answer 1

The use of the flame in the model depicting the separation of the mixture is justified as it allows the water to evaporate and be collected in its pure form, leaving the salt component behind. This is known as distillation.

Step-by-step explanation:

Option B is the correct answer as it accurately describes the process of distillation. Distillation involves heating the mixture of salt water until it boils and evaporates, leaving behind the salt. The water vapor is then cooled and condensed back into liquid form, resulting in pure water. The flame is used to heat the mixture and allow the water to evaporate. The salt, being a solid, remains behind and can be separated from the pure water. Therefore, the use of the flame in the model is necessary to carry out the process of distillation, which is an effective way to separate salt water into its components in order to obtain pure drinking water.