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NCERT exemplar Class 10 Science solutions chapter 1 discusses the chemical reactions and equations. It describes the methods to write chemical changes in the form of chemical reactions. These NCERT exemplar Class 10 Science chapter 1 solutions are prepared by our handpicked subject matter experts and provide elaborate and concrete solutions to the students while exercising the NCERT Class 10 Science questions based on the latest syllabus provided by CBSE 2023. These NCERT exemplar Class 10 Science chapter 1 solutions develop a better understanding of chemical reactions and equations concepts as they are detailed and expressive.
Thus, to provide clear idea of topics and sub topics we provide solutions for NCERT exemplar Class 10 Science chapter wise aligned with the CBSE syllabus for Class 10. for ease students can download the Chemical Reactions and Equations PDF here. Also students can find NCERT Solutions for Class 10 here and practice them to get good hold on the concepts.
Question:1
Which of the following is not a physical change?
(a) Boiling of water to give water vapour
(b) Melting of ice to give water
(c) Dissolution of salt in water
(d) Combustion of Liquefied Petroleum Gas (LPG)
Answer: (d)
(a) Boiling of water to give water vapour – Change in state – Physical changeQuestion:2
The following reaction is an example of a:
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction
(a) (i) and (iv) (b) (ii) and (iii)
(c) (i) and (iii) (d) (iii) and (iv)
Answer: (c)
Question:3
Which of the following statements about the given reaction are correct?
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent
(a) (i), (ii) and (iii) (b) (iii) and (iv)
(c) (i), (ii) and (iv) (d) (ii) and (iv)
Answer: (c)
Question:4
Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
(a) (i) and (ii) (b) (ii) and (iii)
(c) (i) and (iv) (d) (iii) and (iv)
Answer: (a)
When water reacts with water and acid it releases enormous amount of heat. Similarly, when water reacts with quick lime it releases a lot of heat.Question:5
Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is(are) correct?
(i) In beakers A and B, exothermic process has occurred.
(ii) In beakers A and B, endothermic process has occurred.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occurred.
(a) (i) only (b) (ii) only
(c) (i) and (iv) (d) (ii) and (iii)
Answer: (c)
In beaker A:Question:6
A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?
(a) is an oxidising agent, it oxidises
(b) acts as an oxidising agent and oxidises
(c) The colour disappears due to dilution; no reaction is involved
(d) is an unstable compound and decomposes in presence of
to a colourless compound.
Answer: (a)
Question:7
Which among the following is(are) double displacement reaction(s)?
(i)
(ii)
(iii)
(iv)
(a) (i) and (iv) (b) (ii) only
(c) (i) and (ii) (d) (iii) and (iv)
Answer: (b)
Double displacement reactions are those in which ions of the reactants are exchanged to form new compounds as products.Question:8
Which among the following statement(s) is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to:
(i) the formation of silver by decomposition of silver chloride
(ii) sublimation of silver chloride
(iii) decomposition of chlorine gas from silver chloride
(iv) oxidation of silver chloride
(a) (i) only (b) (i) and (iii)
(c) (ii) and (iii) (d) (iv) only
Answer: (a)
Question:9
Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
(i) It is an endothermic reaction
(ii) It is an exothermic reaction
(iii) The pH of the resulting solution will be more than seven
(iv) The pH of the resulting solution will be less than seven
(a) (i) and (ii) (b) (ii) and (iii)
(c) (i) and (iv) (d) (iii) and (iv)
Answer:(b)
Question:10
Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction
(a) (i) only (b) (ii) only
(c) (iv) only (d) (ii) and (iv)
Answer: (d)
Question:11
Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
(a) 1:1
(b) 2:1
(c) 4:1
(d) 1:2
Answer:(b)
The reaction is shown as:Question:12
Which of the following is(are) an endothermic process(es)?
(i) Dilution of sulphuric acid
(ii) Sublimation of dry ice
(iii) Condensation of water vapours
(iv) Evaporation of water
(a) (i) and (iii) (b) (ii) only
(c) (iii) only (d) (ii) and (iv)
Answer: (d)
Dilution of sulphuric acid with water is a highly exothermic process as it occurs with the evolution of heat.Question:13
In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?
(a) Lead sulphate (insoluble)
(b) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
Answer: (b)
Question:14
Which of the following gases can be used for storage of fresh sample of an oil for a long time?
(a) Carbon dioxide or oxygen
(b) Nitrogen or oxygen
(c) Carbon dioxide or helium
(d) Helium or nitrogen
Answer: (d)
Helium can be used as it is an inert gas. Nitrogen is less reactive and it is cheaper than Helium.Question:15
The following reaction is used for the preparation of oxygen gas in the laboratory
Which of the following statement(s) is(are) correct about the reaction?
(a) It is a decomposition reaction and endothermic in nature
(b) It is a combination reaction
(c) It is a decomposition reaction and accompanied by release of heat
(d) It is a photochemical decomposition reaction and exothermic in nature
Answer: (a)
Potassium chlorate decomposes to give potassium chloride and oxygen. This is a decomposition reactionQuestion:16
Which one of the following processes involve chemical reactions?
(a) Storing of oxygen gas under pressure in a gas cylinder
(b) Liquefaction of air
(c) Keeping petrol in a china dish in the open
(d) Heating copper wire in presence of air at high temperature
Answer: (d)
Storing of oxygen gas under pressure in a gas cylinder – does not involve chemical reactionsQuestion:17
Answer: (c)
At room temperature hydrogen and oxygen are gases while water is liquid in nature hence option (c) represents correct states of reactants and products.Question:18
Which of the following are combination reactions?
(i)
(ii)
(iii)
(iv)
(a) (i) and (iii) (b) (iii) and (iv)
(c) (ii) and (iv) (d) (ii) and (iii)
Answer:
Ans. (d)Question:19
Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
(a) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773K to form ammonia gas.
(b) Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.
(c) Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated
(d) Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.
Answer:
Chemical Reactions and EquationsQuestion:20
Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
(a) Thermit reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide.
(b) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.
(c) Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.
(d) Ethanol is burnt in air to form carbon dioxide, water and releases heat.
Answer:
(a) Thermit reaction, iron (III) oxide reacts with aluminum and gives molten iron and aluminum oxide.Question:21
Complete the missing components/variables given as x and y in the following reactions
(a)
(b)
(c)
(d)
Answer:
a) x (s), y (aq)Question:22
Which among the following changes are exothermic or endothermic in nature?
(a) Decomposition of ferrous sulphate
(b) Dilution of sulphuric acid
(c) Dissolution of sodium hydroxide in water
(d) Dissolution of ammonium chloride in water
Answer:
(a) Decomposition of ferrous sulphateQuestion:23
Identify the reducing agent in the following reactions
(a)
(b)
(c)
(d)
Answer:
Reducing agent is the one which reduces other substance (by removal of oxygen or addition of hydrogen) and itself gets oxidised.Question:24
Identify the oxidising agent (oxidant) in the following reactions
(a)
(b)
(c)
(d)
(e)
(f)
Answer:
An oxidizing agent is a reactant that removes electrons from other reactants during a redox reaction. The oxidizing agent typically takes these electrons for itself, thus gaining electrons and being reduced.Question:25
Write the balanced chemical equations for the following reactions
(a) Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.
(b) Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.
(c) Copper sulphate on treatment with potassium iodide precipitates cuprous iodide , liberates iodine gas and also forms potassium sulphate.
Answer:
(a)Question:26
Answer:
Question:27
Answer:
Question:28
Why do fire flies glow at night?
Answer:
Fire flies produces an enzyme called as luciferase which carries oxidation of Magnesium Because of oxidation of Magnesium in presence of atmospheric oxygen fire flies’ glows in the night. This phenomenon of glowing by living organisms is called bioluminescence.Question:29
Answer:
Grapes on the plant do not ferment because of defense mechanism of plants. When grapes are plucked from plant, grapes reacts with yeast to carry out fermentation. Here sugar changes to alcohol and it is a chemical change.Question:30
Which among the following are physical or chemical changes?
(a) Evaporation of petrol
(b) Burning of Liquefied Petroleum Gas (LPG)
(c) Heating of an iron rod to red hot.
(d) Curdling of milk
(e) Sublimation of solid ammonium chloride
Answer:
Physical changes only change the appearance of a substance, not its chemical composition.Question:31
During the reaction of some metals with dilute hydrochloric acid, following observations were made.
(a) Silver metal does not show any change
(b) The temperature of the reaction mixture rises when aluminium(Al) is added.
(c) The reaction of sodium metal is found to be highly explosive
(d) Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain these observations giving suitable reasons.
Answer:
a) There will not be any reaction between silver and dilute HCl as silver lies in low reactive series of metals.Question:32
Answer:
Compound X is Calcium oxide.Question:33
Write a balanced chemical equation for each of the following reactions and also classify them.
(a) Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution.
(b) A piece of sodium metal is added to absolute ethanol to form sodium ethoxide and hydrogen gas.
(c) Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.
(d) Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.
Answer:
(a)Question:34
Why do we store silver chloride in dark coloured bottles?
Answer:
Silver chloride decomposes into silver and chlorine gas when exposed to sunlight.Question:35
Balance the following chemical equations and identify the type of chemical reaction.
(a)
(b)
(c)
(d)
(e)
(f)
Answer:
(a)Question:36
A magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y.
(a) Write the chemical formulae of X and Y.
(b) Write a balanced chemical equation, when X is dissolved in water.
Answer:
(a)Question:37
Answer:
Zinc is more reactive than copper as Zinc is placed above Hydrogen and Copper is placed below hydrogen in the activity series of metals. Because of this Zinc reacts with HCl whereas Copper will not react.Question:38
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
(a) Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
(b) Name the black substance formed and give its chemical formula.
Answer:
a) Silver reacts withQuestion:39
On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed
(a) Write a balanced chemical equation of the reaction.
(b) Identity the brown gas X evolved.
(c) Identity the type of reaction.
(d) What could be the pH range of aqueous solution of the gas X?
Answer:
Blue coloured powder of copper (II) nitrate =Question:40
Give the characteristic tests for the following gases
(a)
(b)
(c)
(d)
Answer:
(a) PassQuestion:41
What happens when a piece of
(a) zinc metal is added to copper sulphate solution?
(b) aluminium metal is added to dilute hydrochloric acid?
(c) silver metal is added to copper sulphate solution?
Also, write the balanced chemical equation if the reaction occurs
Answer:
(a) When Zinc is added to copper sulphate solution Zinc displaces copper to form Zinc sulphate.Question:43
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained.
(a) Write a balanced chemical equation of the reaction involved
(b) What other name can be given to this precipitation reaction?
(c) On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
Answer:
(a) On adding a drop of Barium Chloride solution to an aqueous solution of sodium sulphite, barium sulphite is obtained which is white color precipitate.Question:44
Answer:
Dilute HClThese Class 10 Science NCERT exemplar chapter 1 solutions provide a basic understanding of chemical reactions and equations. This chapter’s learning is essential for all the students who will pursue science in higher classes. Balancing chemical equations is also asked in higher examinations like JEE Advanced and NEET. Students of Class 10 can use these solutions as reference material to better study Chemical Equations and Reactions based practice problems. The solutions available in Class 10 Science NCERT exemplar solutions chapter 1 Chemical Equations and Reactions will prepare the student to easily venture books such as NCERT Class 10 Science, S.Chand by Lakhmir Singh and Manjit Kaur, Chemistry question bank, et cetera.
In order to study this chapter in an offline mode, students can avail the feature of NCERT exemplar Class 10 Science solutions chapter 1 pdf download which will be available soon to solve any queries faced while attempting NCERT exemplar Class 10 Science chapter 1.
Check NCERT Solutions for questions given in the book
Chapter No. | Chapter Name |
Chapter 1 | Chemical Reactions and Equations |
Chapter 2 | Acids, Bases, and Salts |
Chapter 3 | Metals and Non-metals |
Chapter 4 | Carbon and its Compounds |
Chapter 5 | Periodic Classification of Elements |
Chapter 6 | Life Processes |
Chapter 7 | Control and Coordination |
Chapter 8 | How do Organisms Reproduce? |
Chapter 9 | Heredity and Evolution |
Chapter 10 | Light Reflection and Refraction |
Chapter 11 | The Human Eye and The Colorful World |
Chapter 12 | Electricity |
Chapter 13 | Magnetic Effects of Electric Current |
Chapter 14 | Sources of Energy |
Chapter 15 | Our Environment |
Chapter 16 | Sustainable Management of Natural Resources |
Must check NCERT Solution Subject Wise
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The term "rancidity," as covered in Chapter 1 of NCERT Exemplar Solutions for Class 10 Science, refers to a state in which food becomes unappetizing and unpleasant to consume. Typically, rancidity is used to describe the level of oxygen in oils and the resulting damage to food caused by oxygen. When oxygen molecules interact with oil and food, the natural structure of the food is disturbed, resulting in a change in taste and odor. This makes the food unsuitable for consumption. These concepts are concisely explained in the NCERT Solutions for Class 10 Science Chapter 1, which are developed by subject matter experts at Careers360. The solutions are presented in simple language to aid students during revision.
There are a total of 44 questions in NCERT Solutions for Class 10 Science Chapter 1, which include multiple-choice questions, short-answer questions, and long-answer questions. These solutions are designed to improve the students' intelligence levels.
The faculty at Careers360 has designed the NCERT Exemplar Solutions for Class 10 Science Chapter 1 to assist students in confidently acing their board exams. The solutions meticulously cover all fundamental concepts and provide a systematic explanation to enhance students' confidence levels. Additionally, every minute detail is included in the solutions to aid students in their board exam preparation. The solutions are available both online and offline, catering to the individual requirements of students.
In any process, a change in energy is liberated from the system the process is called exothermic.
If energy is required to make any process then the process is known as the endothermic process
students can find these concepts in detail above in this article.
It is also known as a replacement reaction. In this type of reaction, one substance of a compound is replaced or displaced by another substance with similar behavior
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