States Of Matter And Mixtures Flashcards
What is filtration used for?
To separate an insoluble solid from a liquid reaction mixture and for purification.
What is a common example of filtration?
Removing solid impurities from a reaction mixture.
What is the first step in the filtration process?
Fold a piece of filter paper into a cone.
How do you create a cone shape with filter paper?
Fold the paper in half, then in half again, and separate one leaf.
Where should the filter paper be placed during filtration?
In a filter funnel sitting in the neck of a container, such as a conical flask.
What should you ensure when pouring the mixture into the funnel?
None of the mixture goes over the top or down the side of the filter paper.
What happens to the liquid during filtration?
The liquid passes through the filter paper.
What happens to the solid during filtration?
The solid is left behind in the funnel.
Fill in the blank: Filtration is often used if your desired product is an insoluble solid that needs to be separated from a _______.
[liquid reaction mixture]
True or False: The solid will pass through the filter paper during filtration.
False
What is the first step in crystallising soluble solids?
Place an evaporating dish on top of a tripod with a gauze mat
What is used to heat the evaporating dish during crystallisation?
A Bunsen burner
What happens to the solution when it is gently heated?
Some of the water will evaporate and the solution will get more concentrated
At what point should you remove the evaporating dish from heat during crystallisation?
When you see crystals start to form or when some of the water has evaporated
What occurs as the dissolved compound becomes insoluble in the cold solution?
Crystals start to form
What is the final step after filtering the crystals out of the solution?
Leave them in a warm place to dry
What alternative methods can be used for drying the crystals?
A drying oven or a desiccator
Fill in the blank: The point of crystallisation is when _______.
you see crystals start to form
How do you separate a soluble solid and a solution
Crystallization
What is fractional distillation used for?
Separating a mixture of different liquids
When is fractional distillation especially useful?
When the liquids have similar boiling points
What is the first step in the fractional distillation process?
Place the mixture in a flask and attach a fractionating column
What happens to the liquids during fractional distillation?
They evaporate at different temperatures due to different boiling points
Which liquid evaporates first in fractional distillation?
The liquid with the lowest boiling point
What occurs when the temperature on the thermometer matches the boiling point of the lowest boiling liquid?
Its vapour reaches the top of the column and passes into the condenser
What happens to the vapour in the condenser during fractional distillation?
It cools and condenses and runs out of the end
What can be collected after the liquid condenses in fractional distillation?
The pure liquid
What happens to liquids with higher boiling points during fractional distillation?
They might start to evaporate but condense and run back down towards the flask
What should you do after the first liquid has been collected?
Raise the temperature to the next lowest boiling point of the liquids in the mixture
When would you use simple distillation
When the boiling points are significantly different from each other
What is a pure substance
Made of a simple element or compound
What determines how fast a chemical moves in chromatography?
The time it spends in the mobile phase
What is the stationary phase in chromatography?
A solid or a thick liquid where molecules can’t move
What is the mobile phase in chromatography?
A liquid or gas where molecules can move
What happens to the components in a mixture during chromatography?
They separate out as the mobile phase moves over the stationary phase
How does the distribution of chemicals affect their movement in chromatography?
It affects how long they spend on the stationary phase
What is chromatography used for?
To separate a mixture of soluble substances
Chromatography involves how many phases?
Two phases: mobile phase and stationary phase
Fill in the blank: Chromatography is a method used to separate a mixture of _______.
soluble substances
True or False: The mobile phase always consists of a solid.
False
What does the speed of a chemical in chromatography depend on?
The time it spends in the mobile phase
What are the two types of phases involved in chromatography?
Mobile phase and stationary phase
What factors affect how far they move in a chromatogram
Molecules with higher solubility will spend more time in the mobile phase and be carried further up the paper
What is a significant drawback of distillation?
It requires a lot of energy and is expensive.
Why do countries avoid using distillation for water production?
They tend to avoid it if there are other sources of water available.
Fill in the blank: Distillation is especially expensive when used to produce large quantities of _______.
fresh water
What is a significant drawback of distillation?
It requires a lot of energy and is expensive.
Why do countries avoid using distillation for water production?
They tend to avoid it if there are other sources of water available.
Fill in the blank: Distillation is especially expensive when used to produce large quantities of _______.
fresh water
What is the primary purpose of water purification?
To make water potable
Which type of water is typically cleaner, ground water or surface water?
Ground water
What is the first step in the water purification process?
Filtration
What materials are used in the filtration process?
Wire mesh, gravel, and sand
What is the purpose of sedimentation in water purification?
To make fine particles clump together and settle at the bottom
What chemicals are commonly added during the sedimentation process?
Iron sulfate or aluminium sulfate
What is the final step in the water purification process?
Chlorination
What is the purpose of chlorination in water purification?
To kill harmful bacteria and other microbes
Fill in the blank: Ground water from aquifers is normally quite _______.
clean
True or False: Surface water requires less treatment than ground water.
False
What can interfere with experimental results when using water?
Ions present in tap water
These ions include calcium, iron, and copper ions, which can be present in small amounts.
What type of water is recommended to avoid false results in experiments?
Water that had the ions removed
This refers to purified or distilled water that does not contain interfering ions.
True or False: Normal tap water is always safe for experiments.
False
Tap water may contain ions that can affect experimental outcomes.
Fill in the blank: _______ present in tap water can interfere with experiments.
Ions
Examples of these ions include calcium, iron, and copper.
What is a consequence of using normal water in experiments?
It could give a false result
The presence of ions can lead to inaccurate measurements or conclusions.
