Natural Science - Mixtures
NAME:
SET:
DATE:
SECTION A
1.
Complete the following sentences by adding the missing words:
When two liquids are separated by fractional distillation their boiling points should not be …………………………….. to
one another.
2.
A ………………………………………… has its own special property which completely differs from those of its elements.
3.
The ingredients of a …………………………………………… may be mixed in any proportion while the elements of a
………………………………………… are in a fixed proportion.
4.
A mixture of copper sulphate solution and sulphur is separated by ……………………………………………………..
5.
Soluble substances can be removed from water by a single process called ………………………………………………..
6.
Alcohol can be separated from fermented grapes by ……………………………………………..
7.
Pieces of iron are found in a sugar-mill and can be removed by using the …………………………………….. property of iron.
8.
A mixture of solids large enough to be seen by the eye can be separated by ………………………………………
9.
…………………………………… solids in water can be removed by distillation.
10.
Water and oil are …………………………………. liquids because the one does not dissolve in the other.
SECTION B
Choose the correct word in brackets (delete the incorrect word)
1.
The solute in a copper sulphate solution is (water / copper sulphate crystals).
2.
A solution of salt water is frozen in the freezer. The top of the piece of the ice is (tasteless / salty).
3.
A solute can be retrieved by (evaporation / filtration).
4.
A separating funnel is used for the separation of two (miscible / immiscible) substances.
5.
An insoluble powdered solid is mixed with a liquid. The method normally used to separate the powder from the
liquid is (filtration / the method with the separating funnel).
6.
Two immiscible liquids with different densities can be separated by a (Liebig’s condenser / separating funnel).
7.
A water-alcohol mixture is separated by (fractional distillation / a separating funnel).
8.
A mixture of table salt and sand is separated by (filtration / magnetism).
9.
A solution of table salt in water is an example of a solution with a solid and can be separated by (distillation /
filtration).
10.
The difference in (densities / boiling points) is used in fractional distillation.
SECTION C
1.
2.
3.
4.
5.
6.
7.
Choose the best answer from A, B, C, or D of the following questions: (Circle the correct letter)
Which of the following is not a mixture?
A.
air
B.
sea water
C.
pure crystals of table salt
D.
a test tube of iron and lead filings
A separating funnel is used in the separation of
A.
immiscible liquids with different densities
B.
miscible liquids with the same boiling points
C.
miscible liquids with different boiling points
D.
a solvent of the solute
Miscible liquids with different boiling points (about 20ºC difference) can be separated by
A.
a Liebig’s condenser
B.
a separating funnel
C.
filtration
D.
fractional distillation
To remove soluble substances from water with a single process the following is used
A.
filtration
B.
a separating funnel
C.
distillation
D.
evaporation
Which concept in the following sequence does not fit?
A.
separating funnel
B.
filtration
C.
fractional distillation
D.
difference in density
If two liquids mix when they are poured into a holder, we can say these liquids are a
A.
mixture
B.
filtrate
C.
distillate
D.
solution
When a mixture is separated by filtration, the liquid that flows through the filter paper is called the
A.
filtrate
B.
residue
C.
solvent
D.
solution
8.
9.
10.
Two liquids that are immiscible and have different densities, can be separated by
A.
a Liebig’s condenser
B.
a separating funnel
C.
filtration
D.
distillation
When a mixture is separated by filtration, the substance remaining on the filter paper is called the
A.
filtrate
B.
solute
C.
residue
D.
dry substance
When a mixture of paraffin and water is separated by a separating funnel, the following happens:
A.
the less dense paraffin forms a layer on the water
B.
the more dense paraffin forms a layer under the water
C.
the less dense paraffin is in the bottom layer
D.
the more dense paraffin is in the top layer
SECTION D
Answer the following questions in full sentences: (Write your answers in the space provided on the
following page)
1.
(a)
What is a pure substance?
(b)
Give three examples of pure substances.
2.
Name the process by which the mixture of table salt and copper filings will be separated.
3.
Name the apparatus used to separate two immiscible liquids.
4.
Give an example of each of the following:
(a)
a mixture in the gas phase
(b)
a mixture in the liquid phase
(c)
a mixture of two elements
(d)
a mixture of an element and a compound
5.
What is an air filter in a car engine used for?
6.
What would you use to remove the following?
(a)
a paint mark from your sleeve
(b)
a drop of tar from your handkerchief
7.
Name two examples of filters that are used daily.
8.
What would you use to separate the iron filings of a mixture of iron filings and sulphur?
9.
Which experiment would you use to separate a mixture of paraffin and water? Draw a diagram of the
apparatus.
SECTION D
1.
(a)
(b)
2.
3.
4.
(a)
(c)
(b)
(d)
5.
6.
(a)
(b)
7.
8.
9.