Fractional Distillation

As the mixture of ethanol (b.p. 78 ^oC) and water (b.p. 100 ^oC) rises through the fractionating column, what condenses back into a liquid?

• ethanol

• water

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-2

A mixture of ethanol (b.p. 78 ^oC) and water (b.p. 100 ^oC) are separated using fractional distillation.

When the mixture boils, what is at the top of the fractionating column?

• only ethanol

• only water

• mixture of equal % of methanol and water

• mixture with higher % of ethanol

• mixture with higher % of water

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-2

A mixture of ethanol (b.p. 78 ^oC) and methanol (b.p. 65 ^oC) are separated using fractional distillation.

When the mixture first boils, what is present near the bottom of the fractionating column?

• only ethanol

• only methanol

• equal mixture of methanol and ethanol

• mixture with higher % of methanol

• mixture with higher % of ethanol

Tags

NGSS.HS-PS3-4

When the mixture boils, what is present at the top of the fractionating column (at the thermometer)?

• only ethanol

• only methanol

• equal mixture of methanol and ethanol

• mixture with higher % of methanol

• mixture with higher % of ethanol

A mixture of ethanol (b.p. 78 ^oC) and methanol (b.p. 65 ^oC) are separated using fractional distillation. Identify the distillate that is first collected.

• ethanol

• methanol

Two samples are taken, one at point A and another at point B. Each is placed in a separate glass evaporating dish and heated to dryness. The sample from A left a white solid and the sample from B left no residue.  Explain the two observations.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-2

NGSS.MS-PS3-4

Predict the temperature shown on the thermometer.

• 0

• 65

• 78

• 100

Tags

NGSS.MS-PS1-4

What process is used to separate crude oil into different components?

• Chromatography

• Fractional distillation

• Simple distillation

• Filtration

What property of hydrocarbons determines how they are separated in fractional distillation?

• Boiling points

• Molecular weight

• Solubility in water

• Electrical conductivity

What happens to the vapours in the fractionating column during fractional distillation?

• They ignite spontaneously

• They dissolve into each other

• They react chemically

• They condense at different heights