Question

While diluting a solution of salt in water, a student by mistake added methanol(boiling point 64.7${}^{\circ }$C). What technique can be employed to get back the methanol?
Justify your choice.

Answer 1

Methanol is soluble in water, a homogeneous mixture is obtained and hence separation by separating funnel cannot be used. Methanol can be obtained back by simple distillation because the difference in the boiling points of methanol and water is more than 25${}^{\circ }$ C.
Boiling point of methanol: 64.7${}^{\circ }$C
Boiling point of water: 100${}^{\circ }$C
In distillation flask, methanol will boil at 64.7${}^{\circ }$ C and change into vapours and can be collected in the flask after condensation.