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![Selina solutions for Concise Chemistry [English] Class 9 ICSE chapter 2 - Chemical Changes and Reactions - Shaalaa.com](/images/concise-chemistry-english-class-9-icse_6:3baa192b34e3498fa97ae56602d705f0.jpg "Selina solutions for Concise Chemistry [English] Class 9 ICSE chapter 2 - Chemical Changes and Reactions")
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Solutions for Chapter 2: Chemical Changes and Reactions
Below listed, you can find solutions for Chapter 2 of CISCE Selina for Concise Chemistry [English] Class 9 ICSE.
Selina solutions for Concise Chemistry [English] Class 9 ICSE 2 Chemical Changes and Reactions Exercise 2 (A) [Pages 23 - 24]
What is a chemical reaction?
State the conditions necessary for a chemical change or reaction.
Define the following term:
Chemical change
Define the following terms
Chemical bond
Define the following terms:
Effervescence
Define the following terms
Precipitate
Give an example of a reaction where the following are involved
Heat
Give an example of a reaction where the following are involved
Light
Give an example of a reaction where the following are involved
Electricity
Give an example of a reaction where the following are involved:
Close contact
Give an example of a reaction where the following are involved:
Solution
Give an example of a reaction where the following are involved
Pressure
Give an example of a reaction where the following are involved
Catalyst
Define Photochemical reaction
Give an example
Define Electrochemical reaction
Give an example
Give an example of the following chemical changes.
A photochemical reaction involving silver salt.
Give an example of the following chemical changes.
A photochemical reaction involving water.
Give an example of the following chemical changes.
A reaction involving blue solution.
Give an example of the following chemical changes.
A reaction involving formation of dirty green precipitate.
Give an example of the following chemical change.
Two gases combine to form white solid
Give an example of the following chemical change.
Two solids combine to form a liquid
Give an example of the following chemical change.
A reaction where colour change is noticed
Write the chemical reaction where the following changes are observed.
Gas is evolved
Write the chemical reaction where the following changes are observed.
Colour change is noticed
Write the chemical reaction where the following changes are observed.
Precipitate is formed
Write the chemical reaction where the following changes are observed.
Physical state is changed
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
Give reason for the following:
Molybdenum is used in the manufacture of ammonia.
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Selina solutions for Concise Chemistry [English] Class 9 ICSE 2 Chemical Changes and Reactions Exercise 2 (B) [Page 29]
Complete the following statement.
The chemical change involving iron and hydrochloric acid illustrates a _________________ reaction.
Complete the following statement.
In the type of reaction called_______________, two compounds exchange their positive and negative radicals.
Complete the following statement.
A catalyst either ______ or _____________ the rate of a chemical change but itself remains ______________ at the end of the reaction.
Complete the following statement.
On heating, hydrated copper sulphate changes its colour from ________ to __________.
When hydrogen burns in oxygen, water is formed; when electricity is passed through water, hydrogen and oxygen are given out. Name the type of chemical change involved in the two cases.
Explain, giving one example of the following chemical changes:
Double decomposition
Explain, giving one example of the following chemical change:
Thermal dissociation
Explain,giving one example of the following chemical changes:
Reversible reaction
Explain, giving one example for each of the following chemical changes:
Displacement
(a) What is synthesis?
(b) What kind of chemical reaction is synthesis? Support your answer by an example.
Decomposition brought about by heat is known as thermal decomposition. What is the difference between thermal dissociation and thermal decomposition?
(a) Define the neutralization reaction with an example.
(b) Give a balanced equation for this reaction.
(c) Give three applications of neutralization reactions.
What do you understand by precipitation reaction? Explain with examples.
What is a double displacement reaction?
Give an example of double displacement reaction, where a gas is evolved.
What is a decomposition reaction?
Decomposition reactions can occur by heat.
Give two balanced reactions for each.
Decomposition reactions can occur by electricity
Give balanced reactions.
Decomposition reactions can occur by sunlight.
Give two balanced reactions.
State the type of reactions for the following represent and balance the ones that are not balanced.
Cl2 + 2KBr → 2KCl + Br2
State the type of reactions for the following represent and balance the ones that are not balanced.
NaOH + HCl → NaCl + H2O
State the type of reactions for the following represent and balance the ones that are not balanced.
2HgO → 2Hg + O2
State the type of reactions for the following represent and balance the ones that are not balanced.
Fe + CuSO4→ FeSO4 + Cu
State the type of reactions for the following represent and balance the ones that are not balanced.
PbO2 + SO2→ PbSO4
State the type of reactions for the following represent and balance the ones that are not balanced.
2KClO3→ 2KCl + 3O2
State the type of reactions for the following represent and balance the ones that are not balanced.
2H2O2→ 2H2O + O2
State the type of reactions for the following represent and balance the ones that are not balanced.
KNO3 + H2SO4 → HNO3 + KHSO4
State the type of reactions for the following represent and balance the ones that are not balanced.
CuO+H2→ Cu+ H2O
State the type of reactions for the following represent and balance the ones that are not balanced.
CaCO3→ CaO+ CO2
State the type of reactions for the following represent and balance the ones that are not balanced.
NH4Cl → NH3 + HCl
State the type of reactions for the following represent and balance the ones that are not balanced.
PbO + 2HNO3→ Pb(NO3) + 2H2O
State the type of reactions for the following represent and balance the ones that are not balanced.
AgNO3 + NaCl → AgCl + NaNO3
Match the following:
|
a. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) |
i. Photochemical decomposition |
|
b. \[\ce{2AgCI(s) ->[Sunlight] 2Ag(s) + CI2(g)}\] |
ii. Thermal decomposition |
|
c. \[\ce{2KCI ->[Electricity] 2K + CI2}\] |
iii. Displacement reaction |
|
d. \[\ce{2HgO(s) ->[\Delta] 2Hg(s) + O(g)}\] |
iv. Electrolytic decomposition |
Multiple choice:
Which of the following is not a characteristic of a chemical change?
It is irreversible.
No net energy change is involved.
New substance is formed.
Involves absorption or liberation of energy.
Multiple choice:
A reaction of a type: AB + CD → AD + CD, involves
No chemical change
Decomposition of AB and CD
Exchange of ions of AB and CD
Combination of AB and CD
Multiple choice:
The reaction BaCl2(aq) + H2SO4(aq) → BaSO4(s) + 2HCl(aq) is
Displacement reaction
Neutralisation reaction
Decomposition reaction
Double displacement reaction
Multiple choice:
Thermal decomposition of sodium carbonate will produce
Carbon dioxide
Oxygen
Sodium hydroxide
No other product
Selina solutions for Concise Chemistry [English] Class 9 ICSE 2 Chemical Changes and Reactions Exercise 2 (C) [Page 32]
What is a chemical change? Give two examples of chemical change?
Why energy is involved in a chemical change?
What do you understand by 'chemical reaction'?
Give an example of a reaction where the following is involved .
Evolution of heat
Give an example of a reaction where the following is involved .
Absorption of heat
Give an example of a reaction where the following is involved .
High pressure is required
State the main characteristics of chemical reactions. Give at least one example in each case.
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Give an example of the following chemical changes.
An exothermic and an endothermic reaction involving carbon as one of the reactants.
Give an example of the following chemical changes.
A reaction where colour change is noticed.
Define exothermic and endothermic changes. Give two example in each case.
State the effects of endothermic and exothermic reactions on the surroundings.
Define:
Photochemical reaction
Give one example
Define:
Electrochemical reaction
Give one example
Complete and balance the following reaction:
NaCl(aq) + AgNO3(aq) →
Complete and balance the following reaction:
Pb(NO3)2 + KI →
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
Complete and balance the following reaction:
\[\ce{Pb(NO3)2 ->[\Delta]}\]
Complete and balance the following reaction:
\[\ce{NH3 + O2 ->[\Delta]}\]
What do you observe? When
Lead nitrate is heated.
What do you observe? When
Silver chloride is exposed to sunlight.
What do you observe? When Hydrogen peroxide is exposed to sunlight.
What do you observe? When H2S gas is passed through copper sulphate solution.
What do you observe? When
Barium chloride is added to sodium sulphate solution
What do you observe? When
Water is added to the quick lime.
What do you observe? When
Sodium chloride solution is added to silver nitrate solution.
Name a carbonate which do not decompose on heating.
Name a nitrate which produces oxygen as the only gas.
Name a compound which produces carbon dioxide on heating.
Name a nitrate which produces brown gas on heating.
Solutions for 2: Chemical Changes and Reactions
Selina solutions for Concise Chemistry [English] Class 9 ICSE chapter 2 - Chemical Changes and Reactions
Shaalaa.com has the CISCE Mathematics Concise Chemistry [English] Class 9 ICSE CISCE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. Selina solutions for Mathematics Concise Chemistry [English] Class 9 ICSE CISCE 2 (Chemical Changes and Reactions) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.
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Concepts covered in Concise Chemistry [English] Class 9 ICSE chapter 2 Chemical Changes and Reactions are Chemical Reaction, Conditions Necessary for Chemical Reactions, Types of Chemical Change or Chemical Reaction, Direct Combination (or Synthesis) Reaction, Decomposition Reactions, Single Displacement Reactions, Double Displacement Reaction, Energy Change in Chemical Reactions, Chemical Reaction.
Using Selina Concise Chemistry [English] Class 9 ICSE solutions Chemical Changes and Reactions exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in Selina Solutions are essential questions that can be asked in the final exam. Maximum CISCE Concise Chemistry [English] Class 9 ICSE students prefer Selina Textbook Solutions to score more in exams.
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