Worksheet: Filtration and Crystallization
In this worksheet, we will practice separating mixtures using filtration and crystallization, deciding the apparatus needed, and determining when each should be used.
Which of the following methods is the most appropriate for recovering a solute from a solution containing other, more soluble solutes?
Which of the following methods is the most appropriate for separating a solid from a liquid?
Which technique could be used to obtain pure solid copper sulfate from a solution of copper sulfate and sodium chloride in water?
A student dissolves some sodium chloride in water and wants to recover it. Which technique should they use?
A student must separate a sample of sand from a water suspension. Which technique should the student use?
Which of the following methods is most appropriate for separating a solute from a simple mixture of solvent and solute?
Which item of glassware is illustrated below?
- AVolumetric flask
- BErlenmeyer flask
- CBüchner flask
- DDistillation flask
- ERound-bottom flask
A mixture of sand and sodium chloride is commonly known as rock salt. Which of the following shows the correct order needed to separate sodium chloride from rock salt?
- ADissolution in water → filtration → crystallization
- BFiltration → dissolution in water → distillation
- CFiltration → crystallization → dissolution in water
- DCrystallization → dissolution in water → filtration
- EDissolution in water → crystallization → filtration
The given diagram shows the setup for a crystallization process. When should the heat be removed from the evaporating dish?
- AWhen crystals start to form in the dish
- BWhen the solution starts to boil
- CWhen the crystals start to combust
- DOnce the temperature reaches
- EAfter heating for exactly 5 minutes
Why does heating a solution, and evaporating some of the solvent, induce crystallization?
- AHeating causes the solute to oxidize and form crystals.
- BThe solution becomes supersaturated and, upon cooling, causes crystals to form.
- CA higher temperature reduces the amount of solute that dissolves in a solvent.
- DThe energy needed to evaporate the solvent is taken from the energy of crystallization.
A student wants to separate a mixture of sugar and salt. The mixture is first stirred into a beaker of ethanol to dissolve the sugar. A separation process is then used to remove the salt, before evaporation over a water bath yields crystals of sugar.
Why was ethanol used instead of water?
- AEthanol boils at a higher temperature than water.
- BEthanol reacts with salt to form a precipitate.
- CSugar dissolves in ethanol better than in water.
- DWater reacts with sugar.
- EWater dissolves both salt and sugar.
What separation process was used to remove the salt?
The given diagram shows the experimental apparatus for filtration.
What is the name of the solid that remains in the filter paper?
What is the name of the liquid that passes through the filter paper?