Chapter 1 of Science Subject of Class 10 is “Chemical Reactions and Equations”. Practice Questions [ Extra Questions ] for Class 10 Science Chapter 1 are provided on this page.
Class 10 Science Chapter 1 : Chemical Reactions and Equations
Chemical Reaction and Equation is the first chapter of class 10 science ncert book. Apart from the ncert solutions of class 10 science chapter 1 , here we have provided the extra question for practice of chapter 1 Chemical Reaction and equation.
These questions covers the majority of topics of the class 10 science chapter 1 like – oxidation, reductions, types of chemical equations, balanced chemical equations, Types of Chemical Reactions , etc
Chapter 1 : Chemical Reactions and Equations ( Practice Questions )
|Chapter||Chapter 1 : Chemical Reactions and Equations|
|Study Material||Practice Questions ( Extra Question for Practice )|
|Total Questions||35 Questions|
|Text Book||NCERT Text Book|
Class 10 Science Chapter 1 : Chemical Reactions and Equations Practice Questions (Extra Question Answer )
Ques. 1 : What is Rancidity ?
Answer : Rancidity can be defined as a phenomenon due to which a substance changes the taste or flavour of food item because of oxidation.
Ques. 2 : What is the cause of Rancidity ?
Answer : Rancidity is caused because of oxidation of oil and fats
Ques. 3 : How can we prevent Rancidity ?
Answer : We can prevent rancidity by following ways –
- By oxidising anti-oxidants.
- BY keeping a food item in an inert atmosphere.
Ques. 4 : What are anti-oxidants ?
Answer : Anti – oxidants are the chemicals used to prevent oxidation.
Ques. 5 : What is corrosion ?
Answer : Corrosion is a process in which the surface of metals gets eaten up by some gases present in the atmosphere when metals reacts with these gases.
OR When a metals is attacked by substance around it such as moisture , acids, etc. it is said to corrode and this process is known as Corrosion.
Ques. 6 : What is Galvanisation ?
Answer : Galvanisation is defined as a process of coating of Zinc metal over the Fe+2 article.
Ques. 7 : What is the water of crystallisation ?
Answer : The water molecule which form apart of the structure of a crystal are called water of crystallisation.
Ques. 8 : Give some example of chemical having water of crystallisation
Answer : Example 1 : FeSO4.7H2O [ Iron Sulphate Heptohydrate ]
Example 2 : CuSO4. 5H2O [ Copper Sulphate Pentahydrate ]
Example 3 : CaSO4. 2H2O [ Calcium Sulphate dihydrate ]
Ques. 9 : What is Oxidation ?
Answer : Those reaction in which addition of oxygen to a substance or removal of hydrogen from a substance take place .
Example : 2Cu + O2 + Heat -> 2 CuO
Ques. 10 : What is Reduction ?
Answer : Those reaction in which addition of hydrogen to a substance and removal of oxygen takes place are called Reduction.
Example : CuO + H2 + Heat -> Cu + H2O
Ques. 11 : What is Oxidising Agent ?
Answer : Substance which gives oxygen for oxidation or removes hydrogen are known as oxidising agents.
Ques. 12 : What is Reducing Agents ?
Answer : Substance which provides hydrogen for reduction or removes oxygen are known as Reducing Agents.
Ques. 13 : What is Physical Change
Answer : It is a change in which no new substance is formed and can be reversed again. For example : Filling a balloon , etc.
Ques. 14 : What is Chemical Change ?
Answer : It is a change in which a new substance is formed and cannot be reversed again. For Example : Cooking of Food ,etc.
Ques. 15 : What are Reactants and Products ?
Answer : Reactant are the substance which reacts with each other to form a new substance.
Products are the substance which forms when reactants react with each other.
Cu + O2 -> CuO
CU and O2 are Reactants
CuO is a Product
Ques. 16 : What is a chemical Equation and Word Equation?
Answer : The symbolic representation of a true chemical change is called a chemical equation.
OR It is a method of representing a chemical reaction with the help of symbols and formulas of the substance involved in it whereas Word Equation contains names of products and reactants.
Ques. 17 : What are Chemical Reactions ?
Answer : These are the processes in which new substance with new properties are formed.
Ques. 18 : “Skeletal Chemical Equation” Define it ?
Answer : Those chemical equation having different masses on both side of equation are called skeletal chemical equation
Ques. 19 : What is a balanced Equation ?
Answer : Those chemical equation which have equal masses or equal number of atoms on both sides of equation are known as Balanced Chemical Equation.
Ques. 20 : To which side the arrow points in a chemical equation ?
Answer : The arrow head points towards the products, and shows the direction of the reaction.
Ques. 21 : Why do we need to balance the chemical equation ?
Answer : The number of atoms of each element remains same before and after chemical reaction. Therefor we need to balance a chemical equation so that it obeys the law of conservation by mass.
Ques. 22 : What are the methods to balance a chemical equation ?
Answer : There are two methods to balance a chemical equations –
- Hit and Trial Method
- Partial Equation Method
Ques. 23 : What are the limitations of a balanced chemical equation ?
Answer : The limitations of Balanced Chemical Equation are –
- It does not represent the Physical state of Reactants and Products.
- It does not represent the speed of the reactions.
- It does not represent whether the reaction is reversible or irreversible.
- It does not tell about the extent of reactions.
- It does not tell about the medium in which reaction takes place.
Ques. 24 : How can we make a chemical equation more informative ?
Answer : We can make a chemical equation more informative by following ways –
- We can represent the Physical state of reactants and Products.
- We can use symbols (up arrow and down arrow) to show whether the element is gas or a precipitate.
- We cab write the reaction conditions above the arrow.
- We can write the medium in which reaction takes place.
Ques. 25 : What are Exothermic Reactions ?
Answer : Those reactions in which heat is along with the formation of products .
Example of Exothermic Reactions : Burning of Natural Gas .
CH4 + 2O2 ->CO2 + 2H2O
Another Example of Exothermic Reactions : During Digestion , food is broken down into simpler substance . As rice , potatoes , Banana and other such food items get converted into carbohydrates. These carbohydrates are broken down to form glucose. The glucose combines with O2 in cells of our body and provides energy . During this whole process heat is evolved during respiration.
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy
Another Example of Exothermic Reactions : The decomposition of vegetable matter into compost.
Ques. 26 : What are endothermic Reactions ?
Answer : Those reactions which proceeds with the absorption of Heat along with formation of products.
Ques. 27 : Define Precipitation Reaction
Answer : Any reaction that produces a precipitate ( insoluble substance) are known as Precipitation Reaction.
Example : Na2SO4 + BaCl2 -> BaSO4 +2NaCl
Ques. 28 : Write the Types of Chemical Reactions.
Answer : Types of Chemical Reactions –
- Combination Reaction
- Decomposition Reaction
- Displacement Reaction
- Double Displacement Reaction
- Oxidation and Reduction
Ques. 29 : What are Combination Reactions ?
Answer : Those reactions in which two roe more substances combine to form a single substance are known as combination Reactions .
Example : CaO + H2O -> Ca(OH)2
Ques. 30 : What are Decomposition Reactions ?
Answer : These are those reactions in which a compound splits up into two or more simpler substances.
Example : 2FeSO4 -> Fe2SO3 + SO2 + SO3
Ques. 31 : What are Displacement Reactions ?
Answer : Those reactions in which one element takes the place of another element in a compound are known as Displacement Reactions.
Example : Fe + CuSO4 -> FeSO4 + Cu
Ques. 32 : What are Double Displacement Reactions ?
Answer : Those reactions in which two compounds react by exchange of ions to form two new compounds are known as Double Displacement Reactions .
Ques. 33 : What are Thermal Decomposition Reactions ?
Answer : Those reactions in which decompositions is brought about by heat are known as Thermal Decomposition Reactions.
Ques. 34 : What is Photo Decomposition Reaction ?
Answer : Those reactions in which Decomposition is carried out by the light are known as Photo Decomposition Reaction.
Example : 2AgBr + Sunlight -> 2Ag + Br
Ques. 35 : What is Electric Decomposition Reactions ?
Answer : Those reaction in which decomposition is brought up by electricity are known as Electric Decomposition Reactions .
Examples : Electrolysis of Water .
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