Separating Mixtures Quiz
Questions: 16 · 10 minutes
1. A dry mixture contains sand and a solid that changes directly into vapor when gently heated. How could the two solids be separated?
Add both solids to a separating funnel and drain the sand
Filter the dry mixture through filter paper
Heat the mixture and collect the sublimed substance on a cool surface
Use fractional distillation to boil the sand first
2. Two miscible liquids have relatively close boiling points. Which setup is generally more effective than simple distillation for separating them?
A sieve with smaller openings
A separating funnel
A filter funnel with thicker filter paper
Fractional distillation with a fractionating column
3. A black ink sample may contain several soluble dyes. Which method is best for investigating its different colored components?
Sieving
Decantation
Separating-funnel separation
Paper chromatography
4. When setting up paper chromatography, why should the initial sample spots be above the solvent level?
To prevent the samples from dissolving directly into the solvent reservoir
To keep the solvent from rising through the paper
To make every component travel the same distance
To make the paper act as a sieve
5. A container holds dry gravel mixed with much smaller grains of sand. What is the simplest suitable separation method?
Sieving
Simple distillation
Evaporation
Sublimation
6. A cook pours tea through a strainer so that the liquid passes through while the leaves remain behind. Which laboratory method does this most closely model?
Chromatography
Distillation
Filtration
Crystallization
7. A student wants to obtain solid salt from saltwater and does not need to collect the water. Which method can remove the water?
Evaporation
Decantation
Magnetic separation
Sieving
8. In a simple distillation apparatus, what is the main function of the condenser?
To trap insoluble solids before heating
To raise the boiling point of the mixture
To cool vapor so that it becomes liquid distillate
To measure how far a solute travels
9. Which method should be used to collect pure water from a salt solution while leaving the salt behind?
Filtration
Chromatography
Centrifugation
Simple distillation
10. Why might crystallization be preferred to heating a solution until all its solvent has evaporated?
It turns every dissolved substance into a gas
It can form crystals without heating the solute completely to dryness
It separates substances according to magnetism
It works only when the solvent and solute are both insoluble
11. Which method would most directly remove iron filings from a dry mixture of iron filings and sulfur powder?
Filtration
Magnetic separation
Fractional distillation
Evaporation
12. A mixture contains insoluble sand suspended in water. Which method is most suitable for separating the sand from the water?
Filtration
Crystallization
Fractional distillation
Paper chromatography
13. A fine solid remains suspended in a liquid and passes through ordinary filter paper. Which method can speed up its separation by rapidly spinning the mixture?
Paper chromatography
Sublimation
Centrifugation
Fractional distillation
14. Muddy water is left undisturbed until the heavier solid settles. The clear upper liquid is then carefully poured away. What is this pouring step called?
Crystallization
Decantation
Condensation
Chromatography
15. Oil and water form separate liquid layers. Which piece of equipment is designed to separate them by draining one layer from the other?
A filter funnel with filter paper
A separating funnel
An evaporating basin
A fractionating column
16. On a chromatogram, a dye spot travels 6 cm while the solvent front travels 8 cm. What is the dye's retention factor (Rf)?
0.25
14
1.33
0.75