7th Grade > Chemistry
PHYSICAL AND CHEMICAL CHANGES MCQs
Total Questions : 113
| Page 4 of 12 pages
Answer: Option B. -> Flammability
:
B
Physical properties can be observed or measured without changing the composition of matter. They are used to describematter.
Physical propertiesinclude appearance, texture, colour, odour, melting point, boiling point, density, solubility and many others.Flammability is a chemical property of a substance.
:
B
Physical properties can be observed or measured without changing the composition of matter. They are used to describematter.
Physical propertiesinclude appearance, texture, colour, odour, melting point, boiling point, density, solubility and many others.Flammability is a chemical property of a substance.
Answer: Option A. -> calcium carbonate
:
A
When carbon dioxide is passed through limewater, it turns milky due to the formation of calcium carbonate. The reaction involved is given below:
Ca(OH)2(aq)+CO2(g)→CaCO3(s)+H2O(l)
:
A
When carbon dioxide is passed through limewater, it turns milky due to the formation of calcium carbonate. The reaction involved is given below:
Ca(OH)2(aq)+CO2(g)→CaCO3(s)+H2O(l)
Answer: Option C. -> Sublimation
:
C
Sublimation refers to a change of state from solid to gas without the intermediate formation of a liquid.Usually, the gas returns to the solid state on cooling.Here, solid iodine converts to violet vapours of iodine.
:
C
Sublimation refers to a change of state from solid to gas without the intermediate formation of a liquid.Usually, the gas returns to the solid state on cooling.Here, solid iodine converts to violet vapours of iodine.
Answer: Option A. -> True
:
A
Burning of wood is a chemical change in which a new substance along with heat isproduced whereas cutting of wood into small pieces is a physical change as it does not result in the formation of a new substance with different chemical properties. Hence, the given statement is correct.
:
A
Burning of wood is a chemical change in which a new substance along with heat isproduced whereas cutting of wood into small pieces is a physical change as it does not result in the formation of a new substance with different chemical properties. Hence, the given statement is correct.
Answer: Option B. -> False
:
B
This statement is false as global warming is caused by increasing amount of carbon dioxide gas.
:
B
This statement is false as global warming is caused by increasing amount of carbon dioxide gas.
Answer: Option B. -> milky
:
B
When carbon dioxide is passed through lime water, it turns lime water milky due to formation of calcium carbonate.
:
B
When carbon dioxide is passed through lime water, it turns lime water milky due to formation of calcium carbonate.
Answer: Option A. -> physical
:
A
The change in which chemical properties of the original substance remains unchanged and no new substance is formed is called physical change.
Dissolution of sugar in wateris a physical change because it does not result in the formation of a new substance. It is a reversible change as sugar and water can be extracted back from the solution.
:
A
The change in which chemical properties of the original substance remains unchanged and no new substance is formed is called physical change.
Dissolution of sugar in wateris a physical change because it does not result in the formation of a new substance. It is a reversible change as sugar and water can be extracted back from the solution.
Answer: Option A. -> True
:
A
The statue is made of the same stone and changes made during the making of statue changes the physical properties of a substance. Hence, this kind of change is known as a physical change. It is not a chemical change because no new substance is formed as only the shape (physical property) of the stone is changed.
:
A
The statue is made of the same stone and changes made during the making of statue changes the physical properties of a substance. Hence, this kind of change is known as a physical change. It is not a chemical change because no new substance is formed as only the shape (physical property) of the stone is changed.
:
The process of coating a layer of zinc over iron articles is known as galvanization.In this process, a layer of metal such as chromium, or zinc is deposited on iron which helps to prevent the iron objects from rusting. The iron pipes we use in our homes to carry water are galvanised to prevent rusting.
Answer: Option B. -> Crystallisation
:
B
Crystals of copper sulphate are prepared by the method of crystallisation.
The process is as follows:
A cup full of water is taken in a beaker. The water is then heated and when it starts boiling, copper sulphate powder is addedwith stirring. Copper sulphate powder should be added till no more powder can be dissolved. It is then filtered into a china dish and allowed to cool. The solution should be kept undisturbed. After some time, you will see the crystals of copper sulphate.
:
B
Crystals of copper sulphate are prepared by the method of crystallisation.
The process is as follows:
A cup full of water is taken in a beaker. The water is then heated and when it starts boiling, copper sulphate powder is addedwith stirring. Copper sulphate powder should be added till no more powder can be dissolved. It is then filtered into a china dish and allowed to cool. The solution should be kept undisturbed. After some time, you will see the crystals of copper sulphate.
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