Methods of Physical Separation

How do you obtain a pure dry salt sample from a solution?

• Partially filter the water. Leave to evaporate and pat dry with filter paper or put in drying oven, window sill.

• Partially evaporate the water. Leave to crystallise and pat dry with filter paper or put in drying oven, window sill.

• Partially evaporate the water. Leave to filter and pat dry with filter paper or put in drying oven, window sill.

Tags

NGSS.MS-PS3-4

Name the process used to obtain oxygen from liquid air?

• evaporation

• Filtration

• Fractional Distillation

Tags

NGSS.MS-PS1-4

How do you calculate the Rf value of a pigment?

• Distance moved by pigment / Distance moved by solvent

• Distance moved by pigment x Distance moved by solvent

• Distance moved by pigment x Distance moved by filter paper

What is simple distillation used for?

• To separate a gas to from a (dissolved) solid.

• To separate a liquid to from a (dissolved) solid.

• To separate a solid to form a crystal

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

How could you prove that a liquid separated by simple distillation is pure water?

• Use a thermometer to show that boiling point is 100oC

• Use a thermometer to show that boiling point is 80oC

• Use a thermometer to show that boiling point is 10oC

Tags

NGSS.MS-PS1-4

State a separation technique that could be used to separate an undissolved salt from a mixture.

• Filtration

• Crystlisation

• Evaporation

Explain why a salt solution is often made by adding solid base to dilute acid in a beaker until some remains at the bottom of the beaker.

• Makes it easier to stir

• To react all the solutions so the salt solution is gone.

• To react all the acid in the solution so the salt solution is saturated.

Tags

NGSS.MS-PS1-2

n chromatography, explain why the spots of dye must be above the level of the solvent

• So the solvent will run through the spots

• So the solvent will not run

• So it dissolves

Explain how the filter paper separates an insoluble solid from a liquid.

• Liquid goes through paper solid does not pass through

• Liquid does not go through the paper

• Gas goes through paper liquid does not pass through

In chromatography, explain why the line on which dyes are spotted is drawn with pencil

• Pencil lead is soluble

• Pencil lead is insoluble

• Pencil lead is easily lost