What is meant by concentration of a solution?

While diluting a solution of salt in water,a student by mistake added acetone (boiling point $56\,^oC$). What technique can be employed to get back the acetone? Justify your choice.

$(a)$ $7\, g$ of iron filings and $4\, g$ of sulphur powder is treated with dilute sulphuric acid at room temperature. Name the gas produced.
$(b)$ The same mixture is heated strongly,cooled and then treated with dilute sulphuric acid. Which gas would be produced?
$(c)$ What is the cause of this difference in results of chemical reaction in different conditions?

Write your observations when the following processes take place:
$(a)$ An aqueous solution of sugar is heated to dryness.
$(b)$ $A$ saturated solution of potassium chloride prepared at $60^\circ C$ is allowed to cool at room temperature.
$(c)$ $A$ mixture of iron filings and sulphur powder is heated strongly.
$(d)$ $A$ beam of light is passed through a colloidal solution.
$(e)$ $Dil. HCl$ is added to the mixture of iron and sulphur.

Can we separate alcohol dissolved in water by using a separating funnel? If yes,then describe the procedure. If not,explain.

When is a solution said to be saturated? How can you change an unsaturated solution to a saturated solution without adding any more solute to it?