Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions Ch-6 Unit-1

Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions Ch-6(Chemical Reactions) Unit-1(Chemical Reactions). We Provide Step by Step Answers of Objectives, True and False, Incorrect and Correct , Definitions , Match the followings and Short/Long Question Type answers of Ch-6(Chemical Reactions) Unit-1(Chemical Reactions). Visit official Website  CISCE  for detail information about ICSE Board Class-8

Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions Ch-6 Unit-1

Board ICSE
Class 8th
Subject Chemistry
Book Name Goyal Brothers
Chapter-6 Chemical Reactions
Unit-1

Chemical Reactions

Topic Solution of exercise questions
Session 2023-24

OBJECTIVE TYPE QUESTIONS

Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions ch-6 unit-1

Que: A. Fill in the blank spaces by choosing the correct words from the list given below :

List : decomposition, neutralisation, combination, precipitation, displacement

1. The reaction between the hydrogen gas and chlorine gas is a chemical combination reaction.

2. The decomposition of mercuric chloride on heating is a chemical decomposition reaction.

3. The reaction between iron and copper sulphate solution is a chemical displacement reaction.

4. The reaction between an acid and a base is called neutralisation reaction.

5. The reaction between sodium carbonate solution and copper sulphate solution is a precipitation reaction.

Que: B. Statements given below are incorrect. Write the correct statements :

Question: 1. Charcoal burns in air with producing a pop sound along with sparkles.

Answer: Charcoal burns in air with producing a crackling sound along with sparkles.

Question: 2. Red lead oxide on heating strongly forms lead dioxide and oxygen.

Answer: Red lead oxide on heating strongly forms lead dioxide and oxygen.

Question: 3. The reaction between magnesium and oxygen is an endothermic reaction.

Answer: The reaction between magnesium and oxygen is an exothermic reaction.

Question: 4. The decomposition of sodium bicarbonate is an example of exothermic reaction.

Answer: The decomposition of sodium bicarbonate is an example of endothermic reaction.

Question: 5. The reaction between an acid and a base is called precipitation reaction.

Answer: The reaction between an acid and a base is called neutralisation reaction.

Que: C. Match the statements in Column A, with those in Column B :

Column A Column B
1. An oxide exhibits acidic as well as basic also. (a) Precipitation reaction
2. Decomposition of copper carbonate on heating to form copper oxide and carbon dioxide. (b) Displacement reaction
3. The chemical reaction between silver nitrate solution and sodium chloride solution. (c) Endothermic reaction
4. A reaction in which zinc metal dissolves in dilute sulphuric acid. (d) Amphoteric
5. A chemical reaction proceeds with the absorption of heat energy. (e) Decomposition reaction

Answer: 

Column A Column B
1. An oxide exhibits acidic as well as basic also. (a) Amphoteric
2. Decomposition of copper carbonate on heating to form copper oxide and carbon dioxide. (b) Decomposition reaction
3. The chemical reaction between silver nitrate solution and sodium chloride solution. (c) Precipitation reaction
4. A reaction in which zinc metal dissolves in dilute sulphuric acid. (d) Displacement reaction
5. A chemical reaction proceeds with the absorption of heat energy. (e) Endothermic reaction

Que: D. Write ‘True’ or ‘False’ for the following statements :

Statements True/False
1. When two elements combine to form a single compound, the reaction is said to be chemical combination. T
2. The reaction between quick lime and water is an endothermic reaction. F
3. Reaction between magnesium and iron sulphate solution is a chemical. F
4. All non-metallic oxides are known as acidic oxides. T
5. Some of the metallic oxides are known as basic oxides. T

Que: E. Tick (√) the most appropriate answer :

1. Which reaction represents chemical combination ?

(a) 2NaHCO3 → Na2CO3 + H2O + CO2

(b) CaO + H2O → Ca(OH)2

(c) CuSO4 + Fe → FeSO4 + Cu

(d) AgNO3 + NaCl → AgCl + NaNO3

Answer: option (b) CaO + H2O → Ca(OH)2 is correct.

2. Which reaction does not take place?

(a) FeSO4 + Cu → CuSO4 + Fe

(b) Zn + 2HCl → ZnCl2 + H2

(c) Pb(NO3)2 + Mg → Mg(NO3)2 + Pb

(d) ZnSO4 + Mg → MgSO4 + Zn

Answer: option (a) FeSO4 + Cu → CuSO4 + Fe is correct.

3. The chemical reaction which proceeds with release of heat energy is known as

(a) endothermic

(b) exothermic

(c) either (a) or (b)

(d) none of these

Answer: option (b) exothermic is correct.

4. Which one is not a amphoteric oxide?

(a) Al2O3

(b) ZnO

(c) PbO

(d) Na2O

Answer: option (a) Al2O3 is correct.

5. Which one is not a chemical decomposition reaction ?

(a) 2NaHCO3 → Na2CO3 + H2O + CO2

(b) Zn + 2HCl → ZnCl2 + H2

(c) 2Pb3 O4 → 6PbO + O2

(d) CuCO3 → CuO + CO2

Answer: option (b) Zn + 2HCl → ZnCl2 + H2 is correct.

STUDY QUESTIONS

Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions ch-6 unit-1

Question:1.Define the term chemical combination reaction. Support your answer by two examples and write fully balanced chemical equations.

Answer: Reactions in which two or more reactants combine to form one product are called Combination reactions. Examples:

1. Mg+O22MgO

2. C+O2CO2

Question: 2. Define the term chemical decomposition reaction. Support your answer by two examples and write fully balanced chemical equations.

Answer: The reaction in which a single compound breaks down into two or more than two elements or new compounds is called decomposition reaction. Examples:

1. 
2. 

Question: 3. Define the term chemical displacement reaction. Support your answer by two examples and write fully balanced chemical equations.

Answer: A displacement reaction is a type of chemical reaction in which a more reactive metal displaces a less reactive metal from its salt solution. Examples:

1. Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)

2. Cu  +  2AgNO3  ⟶  Cu(NO3)2  +  2Ag

Question: 4. Define the term chemical double displacement reaction. Support your answer by giving one example of neutralisation reaction and one example of precipitation reaction.

Answer: A double displacement reaction is a type of chemical reaction in which positive and negative radicals of two reactants are exchanged which will lead to the formation of the product.

The neutralization reaction is also a kind of double displacement reaction in which an acid reacts with a base to form salt and water. The product salt contains anion from acid and cation from the base.

Example: Solution of Sodium hydroxide(NaOH) reacts with dilute Hydrochloric acid(HCl) to form the salt Sodium chloride(NaCl)and water.

NaOH(aq) + HCl(aq) → NaCl(aq)  +  H2O(l)

Question: 5. (a) Define exothermic reaction with example.

Answer: The chemical reaction in which the heat is released is known as an Exothermic reaction. Examples are the burning of a candle and the reaction of a strong acid with water.

(b) Define endothermic reaction with example.

Answer: The chemical reaction in which the heat is absorbed is known as an Endothermic reaction. Examples are melting ice cubes and melting solid salts.

Question: 6. (a) By giving examples explain acidic oxide.

Answer: An acidic oxide reacts with water and produces an acid. Usually, it is the oxide of non-metals. Examples include SO2, CO2, SO3, Cl2O7, P2O5, and N2O5.

(b) By giving examples explain basic oxide.

Answer: An oxide that exhibits the property of a base is called a basic oxide. Since they are basic, they react with an acid to form a salt. These oxides are formed by the reaction of Oxygen with metals like Magnesium(Mg), Sodium (Na), etc. Basic oxide reacts with water to form a base as shown in the reaction below. Example of basic oxide: Magnesium oxide (MgO), CaO, K2O, Na2O.

Question: 7. By giving examples explain the terms

(a) Amphoteric oxide

Answer: The oxides which behave as both acidic and basic oxides are called amphoteric oxides. Examples- aluminum oxide (Al2O3), zinc oxide (ZnO).

(b) Neutral oxide

Answer: Neutral oxides shows neither acidic nor basic properties. They do not form salt, when reacted with acid or base. Example, Nitric acid(NO), Carbon monoxide

— : end of Chemical Reactions Class-8th Goyal Brothers ICSE Chemistry Solutions ch-6 unit-1:–

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