# Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry chapter 2 - Chemical Changes & Reactions [Latest edition]

## Chapter 2: Chemical Changes & Reactions

ExerciseAdditional QuestionsChemical Changes & ReactionsOthers
Exercise

### Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry Chapter 2 Chemical Changes & ReactionsExercise

Exercise | Q 1

Explain the Silver nitrate solution is kept in coloured reagent bottles in the laboratory.

Exercise | Q 1

Give an example of an endothermic reaction.

Exercise | Q 1

Give one reason why magnetizing a piece of steel is a physical change.

Exercise | Q 1.1

State the following reaction represent oxidation or reduction.

$\ce{Fe++->Fe+++}$

• oxidation

• reduction

Exercise | Q 1.1

The reaction can be classified as:

State which of the following type, take place in the reaction is given below.

$\ce{Cl2 + 2Kl->2KCl + l2}$

• Direct combination

• Decomposition reaction

• Simple displacement

• Double decomposition

• Redox reaction

Exercise | Q 1.2

State the following reaction represent oxidation or reduction.

$\ce{Cl- ->Cl}$

• oxidation

• reduction

Exercise | Q 1.2

The reaction can be classified as:

State which of the following type, take place in the reaction is given below.

$\ce{2Mg + O2->2MgO}$

• Direct combination

• Decomposition reaction

• Simple displacement

• Double decomposition

• Redox reaction

Exercise | Q 1.2

State whether the following reaction is oxidation or reduction.

$\ce{Na->Na+}$

• Oxidation

• Reduction

Exercise | Q 1.3

State the following reaction represent oxidation or reduction.

$\ce{Cu++->Cu}$

• oxidation

• reduction

Exercise | Q 1.3

The reaction can be classified as:

State which of the following type, take place in the reaction is given below.

$\ce{SO2 + 2H2O + Cl2->2HCl + H2SO4}$

• Direct combination

• Decomposition reaction

• Simple displacement

• Double decomposition

• Redox reaction

Exercise | Q 1.4

State the following reaction represent oxidation or reduction.

$\ce{Ag->Ag+}$

• oxidation

• reduction

Exercise | Q 1.4

The reaction can be classified as:

State which of the following type, take place in the reaction is given below.

$\ce{AgNO3 + HCl->AgCl + HNO3}$

• Direct combination

• Decomposition reaction

• Simple displacement

• Double decomposition

• Redox reaction

Exercise | Q 1.5

State the following reaction represent oxidation or reduction.

$\ce{H->H+}$

• oxidation

• reduction

Exercise | Q 1.5

The reaction can be classified as:

State which of the following type, take place in the reaction is given below.

$\ce{4HNO3->4NO2 + 2H2O + O2}$

• Direct combination

• Decomposition reaction

• Simple displacement

• Double decomposition

• Redox reaction

Exercise | Q 1.6

State the following reaction represent oxidation or reduction.

$\ce{Al->Al+++}$

• oxidation

• reduction

### Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry Chapter 2 Chemical Changes & ReactionsAdditional Questions

Additional Questions | Q 1

Explain the term chemical reaction with special reference to reactants and products.

Additional Questions | Q 2

Give a suitable example with an equation to show the representation of a chemical reaction.

Additional Questions | Q 3.1

A chemical reaction is often accompanied by external indications or characteristics.

Additional Questions | Q 3.2

Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.

Additional Questions | Q 4.1

Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.

Additional Questions | Q 4.2

Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.

Additional Questions | Q 5.1

Give a balanced equation for the conversion of an ammonium salt to a basic gas.

Additional Questions | Q 5.2

Give a balanced equation for the conversion of a soluble lead salt to an insoluble lead salt – formed as a white precipitate.

Additional Questions | Q 6.1

Chemical reactions may proceed with evolution of heat. Give an example.

Additional Questions | Q 6.2

Chemical reactions may proceed with absorption of heat. Give an example.

Additional Questions | Q 7.1

Define the following type of chemical change or reaction with a suitable example.

Direct combination reaction or synthesis

Additional Questions | Q 7.2

Define the following type of chemical change or reaction with a suitable example.

Decomposition reaction

Additional Questions | Q 7.3

Define the following type of chemical change or reaction with a suitable example.

Displacement reaction or substitution reaction

Additional Questions | Q 7.4

Define the following type of chemical change or reaction with a suitable example.

Double decomposition reaction

Additional Questions | Q 8.1

Give a balanced equation for a direct combination reaction involving:

Two elements – one of which is a neutral gas and the other a yellow non-metal

Additional Questions | Q 8.2

Give a balanced equation for a direct combination reaction involving:

Two elements – one of which is a neutral gas and the other a monovalent metal

Additional Questions | Q 8.3

Give a balanced equation for a direct combination reaction involving:

Two compounds – resulting in the formation of a weak acid

Additional Questions | Q 9.1

Give a balanced equation for the following reaction of synthesis involving the formation of:

An acid – from sulphur dioxide gas

Additional Questions | Q 9.2

Give a balanced equation for the following reaction of synthesis involving the formation of:

An alkali – from a basic oxide – sodium oxide

Additional Questions | Q 9.3

Give a balanced equation for the following reaction of synthesis involving the formation of:

A salt – from a trivalent metal and a coloured gas.

Additional Questions | Q 10.1

Convert nitrogen to ammonia by a direct combination reaction.

Additional Questions | Q 10.2

Convert hydrogen to hydrogen chloride by a direct combination reaction.

Additional Questions | Q 11.1

Give a balanced equation for thermal decomposition of lead carbonate

Additional Questions | Q 11.2

Give a balanced equation for thermal decomposition of lead nitrate

Additional Questions | Q 11.3

Give a balanced equation for thermal decomposition of ammonium dichromate

Additional Questions | Q 11.4

Give a balanced equation for thermal decomposition of mercury [II] oxide

Additional Questions | Q 11.5

Give a balanced equation for thermal decomposition of calcium hydroxide

Additional Questions | Q 12.1

Define a thermal dissociation reaction with a suitable example.

Additional Questions | Q 12.2

Give an example of a photochemical decomposition reaction.

Additional Questions | Q 12.3

Name a metallic oxide which on thermal decomposition is reduced to metal.

Additional Questions | Q 13.1

Define a displacement reaction with a suitable example.

Additional Questions | Q 13.2

State how displacement reaction represented.

Additional Questions | Q 13.3

Give a reason why zinc displaces hydrogen from dilute sulphuric acid but copper does not.

Additional Questions | Q 14.1

Explain the term double decomposition precipitation reaction.

Additional Questions | Q 14.2

Give a balanced equation for the preparation of two different insoluble lead salts from their salt solutions by double decomposition precipitation.

Additional Questions | Q 15

Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].

Additional Questions | Q 16.1

Define the term – double decomposition – neutralization reaction.

Additional Questions | Q 16.1

State the double decomposition – neutralization reaction with a suitable representation.

Additional Questions | Q 16.2

Convert an insoluble base

Additional Questions | Q 16.2

Convert a soluble base to their respective soluble salts by neutralization reaction.

Additional Questions | Q 17.1

Explain the term energy changes in a chemical change or reaction.

Additional Questions | Q 17.2

Give an example with a balanced equation, of the following reaction:

exothermic reaction

Additional Questions | Q 17.2

Give an example with a balanced equation, of the following reaction:

endothermic reaction

Additional Questions | Q 17.2

Give an example with a balanced equation, of the following reaction:

photochemical reaction

Additional Questions | Q 17.2

Give an example with a balanced equation, of the following reaction:

electrochemical reaction

Additional Questions | Q 18

Supply of energy may be required to initiate a reaction. State the different forms with a suitable example of reactions initiated by the supply of energy.

Chemical Changes & Reactions

### Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry Chapter 2 Chemical Changes & ReactionsChemical Changes & Reactions

Chemical Changes & Reactions | Q 1.1

Complete the statement by filling in the blank with the correct word:

Direct combination reaction of sulphur dioxide with water gives ________.

• $\ce{H2SO4}$

• $\ce{H2SO3}$

• $\ce{H2S2O7}$

Chemical Changes & Reactions | Q 1.2

Complete the statement by filling in the blank with the correct word:

Formation of hydrogen chloride from hydrogen and chlorine is an example of __________.

• photochemical reaction

• electrochemical reaction

Chemical Changes & Reactions | Q 1.3

Complete the statement by filling in the blank with the correct word:

The reaction of hydrogen burning in oxygen to give a neutral liquid is an example of ________ reaction.

• exothermic

• endothermic

Chemical Changes & Reactions | Q 1.4

Complete the statement by filling in the blank with the correct word:

The neutral gas evolved when lead nitrate undergoes thermal decomposition is _________.

• nitrogen dioxide

• oxygen

• nitrogen

Chemical Changes & Reactions | Q 1.5

Complete the statement by filling in the blank with the correct word:

The reddish-brown precipitate obtained during a double decomposition precipitation reaction between an iron salt and alkali is __________.

• iron [II] hydroxide

• iron [III] hydroxide

Chemical Changes & Reactions | Q 2.1

Select the correct answer from the options given below:

State the gaseous product formed, when

An active metal reacts with dilute sulphuric acid.

• Ammonia

• Hydrogen chloride

• Hydrogen

• Nitrogen dioxide

• Nitric oxide

Chemical Changes & Reactions | Q 2.2

Select the correct answer from the options given below:

State the gaseous product formed, when

A metallic nitrate undergoes thermal decomposition giving a coloured gas.

• Ammonia

• Hydrogen chloride

• Hydrogen

• Nitrogen dioxide

• Nitric oxide

Chemical Changes & Reactions | Q 2.3

Select the correct answer from the options given below:

State the gaseous product formed, when

Two gases one of them neutral combines by absorption of light energy.

• Ammonia

• Hydrogen chloride

• Hydrogen

• Nitrogen dioxide

• Nitric oxide

Chemical Changes & Reactions | Q 2.4

Select the correct answer from the options given below:

State the gaseous product formed, when

An ammonium salt reacts with an alkali.

• Ammonia

• Hydrogen chloride

• Hydrogen

• Nitrogen dioxide

• Nitric oxide

Chemical Changes & Reactions | Q 2.5

Select the correct answer from the options given below:

State the gaseous product formed, when

An exothermic reaction takes place between ammonia and neutral gas.

• Ammonia

• Hydrogen chloride

• Hydrogen

• Nitrogen dioxide

• Nitric oxide

Chemical Changes & Reactions | Q 3.1

Give a balanced equation for the following type of reaction:

A direct combination reaction between phosphorus and neutral gas.

Chemical Changes & Reactions | Q 3.2

Give a balanced equation for the following type of reaction:

A soluble salt of lead formed from an insoluble base by double decomposition – neutralization.

Chemical Changes & Reactions | Q 3.3

Give a balanced equation for the following type of reaction:

A thermal decomposition reaction of a salt – which results in the formation of nitrogen gas.

Chemical Changes & Reactions | Q 3.4

Give a balanced equation for the following type of reaction:

A synthesis reaction between a metal and a non-metal resulting in the formation of an insoluble salt of iron.

Chemical Changes & Reactions | Q 3.5

Give a balanced equation for the following type of reaction:

A decomposition reaction of a salt which leaves behind a silvery metal.

Chemical Changes & Reactions | Q 4.1

Differentiate between the following:

Synthesis reaction and a substitution reaction.

Chemical Changes & Reactions | Q 4.2

Differentiate between the following:

Electrolytic decomposition and photochemical decomposition.

Chemical Changes & Reactions | Q 4.3

Differentiate between the following:

Thermal decomposition & thermal dissociation.

Q 4.4

Differentiate between the following:

Decomposition reaction and a double decomposition reaction.

Q 4.5

Differentiate between the following:

Neutralization reaction and a precipitation reaction.

Q 5

Match the chemical reactions in List I with the appropriate answer in List II.

 List I List II 1. $\ce{AB⇌[heat]A + B}$ A: Double decomposition 2. $\ce{AB->A + B}$ B: Thermal dissociation 3. $\ce{X+Y- + AB+B- ->X+B- + A+Y-}$ C: Endothermic reaction 4. $\ce{X + YZ->XZ + Y}$ D: Displacement reaction 5. $\ce{X + Y->[heat]XY - \Delta}$ E: Decomposition reaction
Q 6.1

Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Copper nitrate.

Q 6.2

Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Ammonium dichromate.

Q 6.3

Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Zinc carbonate.

Q 6.4

Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Q 6.5

Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Calcium hydroxide.

## Chapter 2: Chemical Changes & Reactions

ExerciseAdditional QuestionsChemical Changes & ReactionsOthers

## Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry chapter 2 - Chemical Changes & Reactions

Viraf J. Dalal solutions for Class 9 Simplified ICSE Chemistry chapter 2 (Chemical Changes & Reactions) 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 9 Simplified ICSE Chemistry solutions in a manner that help students grasp basic concepts better and faster.

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Concepts covered in Class 9 Simplified ICSE Chemistry chapter 2 Chemical Changes & Reactions are Classification of Change: Chemical Changes, Condition for a Chemical change, Energy Changes in a Chemical Change, Burning - Definition and Conditions of Burning, Comparison of Respiration and Burning, Burning of Magnesium Or Candle to Show that Substances Gain Weight on Burning, Types of Chemical Change or Chemical Reaction, Classification of Change: Chemical Changes.

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