Question

A student has a sample of an insoluble solid and a liquid. The task is to separate the mixture into its pure components. What question is best asked in the design of the experiment to determine how to separate the components?
A) Is the solid/liquid mixture toxic in its combined form?

B) Is the solid large enough to be caught by the pores of a filter?

C) Is the melting temperature of the solid lower than that of the liquid?

D) Can the solid be crushed into smaller particles to allow for distillation?

Answer 1

Answer:

• B) Is the solid large enough to be caught by the pores of a filter?

Explanation:

An insoluble solid and a liquid form an heterogeneous mixture, meaning the liquid and the solid could be separated by physical media.

If the size of the solid particles are large enough it could be separated from the liquid by filtration.

Since, the task is to separate the mixture into its pure components, the best and first step is to determine whether the solid particles have the size that permit to retain them in the available fliter, which is described by the option B): is the solid large enough to be caught by the pores of a filter?

As for the other options:

A) Is the solid/liquid mixture toxic in its combined form?

• a mixture is not more toxic than its pure components, because they are a physical combination and not a chemical one.

C) Is the melting temperature of the solid lower than that of the liquid?

• you do not want to melt the solid, because that would make the separation more difficult.

D) Can the solid be crushed into smaller particles to allow for distillation?

• crushing the solid will not make it soluble and will not change the boiling point of the solution, thus this is not a step to separate the mixture into its components.