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Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 2 - Physical and Chemical Changes [Latest edition]

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Class 7 New Simplified Middle School Chemistry - Shaalaa.com

Chapter 2: Physical and Chemical Changes

ExerciseObjective Type Questions
Exercise

Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry Chapter 2 Physical and Chemical Changes Exercise

Exercise | Q 1.1

Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.

Desirable and undesirable change.

Exercise | Q 1.2

Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.

Periodic and non-periodic change

Exercise | Q 1.3

Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.

Slow and fast change.

Exercise | Q 1.4

Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.

Natural and man-made change.

Exercise | Q 1.5

What are reversible and irreversible changes ? Give one example for each.

Exercise | Q 2.1

Differentiate between a physical change and a chemical change with reference to – Nature of change is temporary and reversible or permanent and irreversible.

Exercise | Q 2.2

Differentiate between a physical change and a chemical change with reference to – Formation of products.

Exercise | Q 2.3

Differentiate between a physical change and a chemical change with reference to – Energy change taking place during the respective change.

Exercise | Q 3

Give three reasons why melting of wax, is considered a physical change while burning of a candle, a chemical change.

Exercise | Q 4

State the observations seen, when milk in a dish is kept aside for a few hours or more. Is the change which occurs – a physical change or a chemical change. Give reasons.

Exercise | Q 5

State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.

Exercise | Q 6

Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification is freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.

Exercise | Q 7

Explain the term – ‘sublimation’. Is sublimation of naphthalene – a physical or a chemical change. Give reasons.

Exercise | Q 8

Ammonium chloride is also a sublimable solid. Give a reason why the sublimation of ammonium chloride involves a physical and a chemical change.

Exercise | Q 9

State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.

Exercise | Q 10.1

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.

Are any new products formed during the above process.

Exercise | Q 10.2

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.

Can the change be reversed or is it irreversible?

Exercise | Q 10.3

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.

State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.

Exercise | Q 11

Give reasons why – separation of mixtures e.g. iron from a mixture of iron and sulphur is a physical change, but heating a mixture of iron and sulphur is considered a chemical change.

Exercise | Q 12

Explain in brief the involvement of energy in physical and chemical changes.

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Objective Type Questions

Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry Chapter 2 Physical and Chemical Changes Objective Type Questions

Objective Type Questions | Q 1.1

Fill in the blank with the appropriate word of the statement given below:

Germination of seeds is considered a __________ change.

Objective Type Questions | Q 1.2

Fill in the blank with the appropriate word of the statement  given below:

If a change is permanent and irreversible it is considered a _________ change.

Objective Type Questions | Q 1.3

Fill in the blanks with the appropriate words of the statement  given below:

Heating a piece of iron is considered a __________ change while heating a piece of coal [carbon] is considered a ___________ change.

Objective Type Questions | Q 1.4

Fill in the blanks with the appropriate words of the statement  given below:

Chemical changes may involve exchange of energy in the form of __________ and _________.

Objective Type Questions | Q 1.5

Fill in the blank with the appropriate word of the statement given below:

Change of milk of curd is a _______ change.

Objective Type Questions | Q 2.1

State whether the following statement is true or false. If false write the correct statement.

Desirable changes are meaningful, while undesirable changes are unfavourable.

  • True

  • False

Objective Type Questions | Q 2.2

State whether the following statement is true or false. If false write the correct statement.

During physical changes, the composition of the original substance is not altered, but the properties of the original substance are altered.

  • True

  • False

Objective Type Questions | Q 2.3

State whether the following statement is true or false. If false write the correct statement.

During a chemical change the composition of the original substance is not altered and the change is irreversible.

  • True

  • False

Objective Type Questions | Q 2.4

State whether the following statement is true or false. If false write the correct statement.

Melting of butter and wax are examples of chemical changes.

  • True

  • False

Objective Type Questions | Q 2.5

State whether the following statement is true or false. If false write the correct statement.

Melting of ice is an exothermic, irreversible chemical change.

  • True

  • False

Objective Type Questions | Q 3

Match the examples of changes in List I with the correct.

List I List II
1. Expansion of a steel rod on heating A: Physical change
2. Rotting of eggs B: Chemical change
3. Milk turning sour  
4. Tarnishing of copper  
5. Separation of naphthalene from a mixture of naphthalene and sodium chloride.  
Objective Type Questions | Q 4.1

Fill in the blank with the correct word of the statement given below:

Sublimation is _______ a change of state of matter.

Objective Type Questions | Q 4.2

Fill in the blank with the correct word of the statement given below:

Sublimation involves a __________ change.

Objective Type Questions | Q 4.3

Fill in the blanks with the correct words of the statement given below:

During sublimation, a solid on heating turns directly into _________ and on cooling back to __________.

Objective Type Questions | Q 4.4

Fill in the blank with the correct word of the statement given below:

Ammonium chloride, a sublimable solid undergoes _________ on heating.

Objective Type Questions | Q 4.5

Fill in the blank with the correct word of the statement given below:

Sublimation of iodine is an example of _________ change.

Objective Type Questions | Q 5.1

Name the following:

The products obtained during ‘photosynthesis’ – which is a chemical change.

Objective Type Questions | Q 5.2

Name the following:

The term involved in the change of state from – ‘water to ice’ – which is a physical change.

Objective Type Questions | Q 5.3

Name the following:

The final product of the physical change involved during the ‘melting of a piece of wax’.

Objective Type Questions | Q 5.4

Name the following:

The type of change physical or chemical involved – ‘during respiration in human beings’.

Objective Type Questions | Q 5.5

Name the following:

The type of change physical or chemical involved – ‘when a substance undergoes a change in state, colour or size’.

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Chapter 2: Physical and Chemical Changes

ExerciseObjective Type Questions
Class 7 New Simplified Middle School Chemistry - Shaalaa.com

Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 2 - Physical and Chemical Changes

Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 2 (Physical and Chemical Changes) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CISCE Class 7 New Simplified Middle School Chemistry solutions in a manner that help students grasp basic concepts better and faster.

Further, we at Shaalaa.com provide such solutions so that students can prepare for written exams. Viraf J. Dalal textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.

Concepts covered in Class 7 New Simplified Middle School Chemistry chapter 2 Physical and Chemical Changes are Types of Change Involved When There is a Change of Energy., Classification of Change: Physical Changes, Classification of Change: Physical Changes, Classification of Change: Physical Changes, Classification of Change: Chemical Changes, Change of State of Matter.

Using Viraf J. Dalal Class 7 solutions Physical and Chemical Changes exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in Viraf J. Dalal Solutions are important questions that can be asked in the final exam. Maximum students of CISCE Class 7 prefer Viraf J. Dalal Textbook Solutions to score more in exam.

Get the free view of chapter 2 Physical and Chemical Changes Class 7 extra questions for Class 7 New Simplified Middle School Chemistry and can use Shaalaa.com to keep it handy for your exam preparation

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