Filtration and Crystallisation Questions Flashcards
What is filtrate?
liquid that has been filtered
What is solute?
dissolved substance in a solution
What is a solvent?
the liquid in which the solute dissolves to form a solution
What is solubility?
The mass of solute that dissolves in a given volume of solvent at a given temperature.
A student wants to produce some copper sulfate crystals from copper sulfate solution. She heats the solution in an evaporating basin to remove some of the water.
(It is better to make a concentrated/saturated solution than to remove all the water. The crystals will be a better size and shape, and will not spit out of the evaporating basin.)
Describe the steps that she should then take to obtain dry crystals of copper sulfate.
She should let the solution cool down so that crystals form. She should then decant the remaining liquid and dry the crystals in an oven.
(Decanting = pouring the liquid away so that the solid stays behind. The student could also use filtration, or pat them dry using filter paper.)
Glass and dust are insoluble in water but copper chloride is soluble.
Outline a method to produce dry copper chloride from a mixture of broken glass, dust and copper chloride.
- Add water to dissolve the copper chloride.
- Filter to remove the glass and dust (as a residue).
- Heat the filtrate to produce copper chloride crystals (by crystallisation).
- Pat the copper chloride crystals dry with filter paper/put them in a warm oven.
