Test: Physical And Chemical Changes - 3


20 Questions MCQ Test General Science for UPSC (Civil Services) Prelims | Test: Physical And Chemical Changes - 3


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This mock test of Test: Physical And Chemical Changes - 3 for Class 7 helps you for every Class 7 entrance exam. This contains 20 Multiple Choice Questions for Class 7 Test: Physical And Chemical Changes - 3 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Physical And Chemical Changes - 3 quiz give you a good mix of easy questions and tough questions. Class 7 students definitely take this Test: Physical And Chemical Changes - 3 exercise for a better result in the exam. You can find other Test: Physical And Chemical Changes - 3 extra questions, long questions & short questions for Class 7 on EduRev as well by searching above.
QUESTION: 1

The reason for a physical change to be named as such is that the:

Solution:

change occurs only in physical properties

QUESTION: 2

When ice is heated, it changes to water and water on further heating gets converted to steam. What happens when steam is condensed?

Solution:

The process of change from gaseous to liquid phase is called condensation. Steam (water in gaseous state) after condensation yields water (liquid state).

QUESTION: 3

A change is a chemical change when it is accompanied by:

Solution:

Chemical changes occur when a substance combines with another to form a new substance. These processes are called chemical reactions and, in general, are not reversible.

QUESTION: 4

Which of the following will be observed if an apple slice is left exposed to air?

Solution:

Apples turn brown when exposed to air because of the oxidation process that goes on when the inside of the apple gets exposed to the ambient air which contains oxygen and water molecules. 

QUESTION: 5

The shipping industry has to bear huge financial loss because of rusting of ships. The rusting of ships occur because:

Solution:

Rusting is a phenomena of formation of oxide layer on metal surface in presence of air and moisture.

QUESTION: 6

Which is the best method to prevent rusting?

Solution:

Galvanizing is an ideal method to prevent rusting.    

QUESTION: 7

A change in which the original substance can be obtained back by change of conditions is called:

Solution:

Reversible changes are changes that can be undone or reversed.Physical changes like Melting, freezing, boiling, evaporating, condensing, dissolving and also, changing the shape of a substance are examples of reversible changes.

QUESTION: 8

When magnesium is burnt, heat and light are produced. The burning of magnesium is a:

Solution:

A change accompanied by evolution of heat is an exothermic change.

QUESTION: 9

Change of milk to curd is a:

Solution:

It is a chemical change. Properties of curd are different from those of milk.

QUESTION: 10

Expansion on heating and contraction on cooling of metals is a:

Solution:
QUESTION: 11

Which of the following changes is accompanied by sound?

Solution:

When you shoot certain types of fireworks, such as rockets, you'll hear the whistling sound as the firework goes up and then a bang as it explodes. Just like firework manufacturers did with the colours, they found out that different chemicals create different sounds.

QUESTION: 12

Hydrochloric acid is added to a beaker containing a piece of zinc. Zinc chloride is formed and hydrogen gas is released. This is an example of:

Solution:

A chemical reaction happens when one or more chemicals are changed into one or more other chemicals.

QUESTION: 13

Which of the following statements is correct?

Solution:

Digestion of food is a chemical change

QUESTION: 14

Which of the following statements is correct?

Solution:

For formation of rust both water vapour and oxygen are essential.

QUESTION: 15

Which of the following statements is correct?

Solution:

Iron pipes coated with zinc do not rust easily.

QUESTION: 16

Which of the following statements is correct?

Solution:

Properties of rust is different from iron.

QUESTION: 17

The process used to prevent rusting of iron, in which a thin coat of zinc is provided over iron surface. This process is:

Solution:

The process is galvanizing.

QUESTION: 18

Chemical change that is accompanied by evolution of heat energy is:

Solution:

An exothermic reaction is a chemical reaction that releases energy through light or heat. It is the opposite of an endothermic reaction.

QUESTION: 19

Characteristic of matter exhibited without a change in its identity is:

Solution:

Thermal properties are those properties of a material which is related to its conductivity of heat.Therefore it doesn't cause any change in its identity.

QUESTION: 20

In which one of the following situations chemical reaction does not occur?

Solution:

Air and salt are not miscible and will not mix. Therefore no chemical reaction takes place.