Science - Separation of Substances
Exam Duration: 45 Mins Total Questions : 30
What type of a substance is steel?
- (a)
A solid-liquid heterogeneous mixture
- (b)
A solid - solid heterogeneous mixture
- (c)
A solid - solid homogeneous mixture
- (d)
A pure substance
flow chart which gives the techniques a student adopted to separate the constituents of a mixture.
What could substance R be?
- (a)
Sugar
- (b)
Chalk powder
- (c)
Glass
- (d)
Oxygen
How are grain seeds removed from their stalks?
- (a)
Sieving
- (b)
Winnowing
- (c)
Threshing
- (d)
All of the above
A compound has
- (a)
only one kind of mixture.
- (b)
only one kind of element.
- (c)
a mixture of elements and molecules.
- (d)
only one kind of molecules
Identify the mixture from the following.
- (a)
Oxygen
- (b)
Carbon dioxide
- (c)
Hydrogen
- (d)
Air
Which of the following is an example of a solid-in-gas mixture?
- (a)
Soil
- (b)
Smoke
- (c)
Moisture
- (d)
Dew
In a mixture, constituents exhibit
- (a)
similar properties.
- (b)
only those properties which are characteristic to the mixture.
- (c)
their own properties.
- (d)
no properties.
The sky looks clearer and brighter after the rain due to loading by rain drops. Which of the following is similar to the process mentioned above?
- (a)
Separation of butter from curd.
- (b)
Separation of salt from sea water.
- (c)
Sprinkling water on a dusty street before sweeping.
- (d)
Separation of grain seeds from their stalks.
'X' is a separation technique used only when the components of a solid-solid mixture have different sizes. Identify 'X:
- (a)
Winnowing
- (b)
Sieving
- (c)
Threshing
- (d)
Magnetic separation
Given below are some methods of separation.
x - Winnowing
Y - Threshing
Z - Sieving
Which of the following methods of separation does not require air for the process of separation?
- (a)
Only X
- (b)
Only Y, Z
- (c)
Only Z, X
- (d)
X, Y and Z
Study the table given below.
Mixture | Wanted component | Unwanted components |
---|---|---|
1. Wheat flour | Flour | X |
2. Y | Grain Seeds | Stalks |
Based on the above information, identify 'X' and 'Y'.
- (a)
x y Husk Cut paddy - (b)
x y Wheat Husk - (c)
x y Wheat Sawdust - (d)
x y Husk Sand
What happens when distilled water is evaporated?
- (a)
Some salt is left behind.
- (b)
Some sand is left behind.
- (c)
Some sugar is left behind.
- (d)
Nothing is left behind.
Which process is used for separating a mixture of water and sulphur?
- (a)
Filtration
- (b)
Winnowing
- (c)
Evaporation
- (d)
Distillation
Which of the following are involved in filtration technique?
- (a)
Hair in our nostrils
- (b)
Oil and air filters in cars
- (c)
Air filters in air conditioners
- (d)
All of the above
Nisha poured a mixture of salt, iron filings, sand and flour into a container.
Which of the following substances can be separated from the mixture by using a magnet?
- (a)
Salt
- (b)
Flour
- (c)
Sand
- (d)
Iron filings
The flow chart given below are examples of materials X and Y.
Identify X and Y.
- (a)
x y Non metals Metals - (b)
x y Mixtures Metals - (c)
x y Compounds Elements - (d)
x y Compounds Pure substances
By which method is wheat flour separated from wheat bran?
- (a)
Handpicking
- (b)
Sieving
- (c)
Winnowing
- (d)
Filtration
Which of the following is NOT a pure substance?
- (a)
Argon
- (b)
Helium
- (c)
Water
- (d)
Air
A glass filled with ice cubes is kept on a table. After sometime water drops were observed sticking to the outside of the glass. Which of these sentences is TRUE of this phenomenon?
(i) This phenomenon is known as condensation.
(ii) This proves that water vapour is present in air.
(iii) This is also observed when a hot object is cooled in the open.
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ii) and (iii)
Anshu prepared tea by boiling water with tea leaves, milk and sugar.
What happens to the colour of water once the ingredients are added and the tea has started to boil?
- (a)
The colour changes.
- (b)
There is no change in colour.
- (c)
Addition of sugar causes colour change.
- (d)
all of these.
Anshu prepared tea by boiling water with tea leaves, milk and sugar.
What can be done to drink this tea if there has been too much of sugar in this tea?
- (a)
Sugar should be removed with a strainer.
- (b)
This tea should be taken as such or thrown away as nothing can be done about the sugar content.
- (c)
Tea will have to be prepared afresh with less tea.
- (d)
Tea without sugar will have to be prepared and then mixed with this tea if we need to drink this tea.
Butter can be separated from milk or curd by
- (a)
mixing.
- (b)
churning
- (c)
using a juicer
- (d)
all of these.
If there are some stones mixed with rice grains, we can remove these stones by
- (a)
threshing.
- (b)
winnowing
- (c)
adding water and then decantation.
- (d)
handpicking.
There is a lot of husk in wheat grains. Which method should be used to separate the grains?
- (a)
sieving
- (b)
handpicking
- (c)
threshing
- (d)
winnowing
To obtain common salt from sea water we
- (a)
condensation.
- (b)
evaporation.
- (c)
sieving.
- (d)
none of these
Pulkit takes a jug of water and adds a spoon of salt to it. He then adds a spoon of sand to it. He calls his sister and asks her to separate the three and recover all three components. His sister should
- (a)
decant and remove the sediments of sand. She should then filter it to remove any left out sand. The water containing salt should be heated strongly in a kettle. Salt will be left in the kettle after all the water has been turned into steam.
- (b)
first stir the water to dissolve all the salt. Then she should decant and remove the sediments of sand. She should then filter it to remove any left out sand. The water containing salt should be heated strongly in a kettle. Salt will be left in the kettle after all the water has been turned into steam.
- (c)
decant and remove the sediments of sand. She should then filter it to remove any left out sand. The water containing salt should be heated strongly in a kettle and the steam allowed to get condensed on a cool plate (by keeping ice on the plate). The condensed water can be collected in a vessel. Salt will be left in the kettle after all the water has been turned into steam.
- (d)
first stir the water to dissolve all the salt. Then she should decant and remove the sediments of sand. She should then filter it to remove any left out sand. The water containing salt should be heated strongly in a kettle and the steam allowed to get condensed on a cool plate (by keeping ice on the plate). The condensed water can be collected in a vessel. Salt will be left in the kettle after all the water has been turned into steam.
Shalu found that there is too much ghee in a particular curry. To remove excess of ghee, she should
- (a)
put the curry in the fridge to cool.
- (b)
remove ghee from top with the help of a ladle.
- (c)
put the curry in the fridge to cool and then remove ghee from top with the help of a ladle.
- (d)
none of these
Select the right match
Column I | Column II |
i) chalk powder and water | A) handpicking |
ii) oil and water | B) separating funnel |
iii) rice and peas from cooked pulao | C) sedimentation and decantation |
- (a)
i-C; ii-B; iii-A
- (b)
i-B; ii-A; iii-C
- (c)
i-A; ii-C; iii-B
- (d)
i-B; ii-C; iii-A
The dalia (broken wheat) that Aastha bought had a lot of dried husk in it. To remove the unwanted husk, Aastha should______________it.
- (a)
handpick
- (b)
winnow
- (c)
filter
- (d)
all of these
There is a lot of air pollution and there is a high increase in particulate matter in the air of Delhi. Every day we see a layer of dust on the furniture. This is due to the fact that
- (a)
dusting is not a priority with us.
- (b)
dust gets removed from air.
- (c)
air is not circulating properly.
- (d)
particulate matter like dust is heavier and tends to settle down due to gravity