Chapter 1 of Science Subject of Class 10 is “Chemical Reactions and Equations”. NCERT Solutions for Class 10 Science Chapter 1 are provided on this page.
Class 10 Science Chapter 1 : Chemical Reactions and Equations
Chapter 1 of Class 10 Science NCERT Text book is Chemical Reactions and Equations. The end exercise of this chapter consists of a total of 20 question. These end exercise questions are related to chemical reaction and balancing of equations. It also consist of the question related to concepts like types , examples of different chemical equations, Oxidation, Reduction , etc . You will find the NCERT solution of each question of Class 10 Science Chapter 1 on this post.
Chapter 1 : Chemical Reactions and Equations ( NCERT Solutions )
| Subject | Science |
| Class | 10 |
| Chapter | Chapter 1 : Chemical Reactions and Equations |
| Study Material | NCERT Solutions ( End Exercise and Intext Questions ) |
| Total Questions | 20 Questions |
| Text Book | NCERT Text Book ( Updated Syllabus) |
End Exercise Solutions
Class 10 Science Chapter 1 Question 1 :
Which of the statements about the reaction below are incorrect?
2PbO(s) + C(s) → 2Pb(s) + CO2(g)
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and (c)
(iv) all
Answer and Explanation : Option [i] “(a) and (b)” is correct answer.
Statement ‘a’ and ‘b’ are incorrect.
Carbon is getting oxidized
Lead oxide is getting reduced.
Class 10 Science Chapter 1 Question 2 :
Fe2O3 + 2Al → Al2O3 + 2Fe
The above reaction is an example of a
(a) combination reaction.
(b) double displacement reaction.
(c) decomposition reaction.
(d) displacement reaction.
Answer and Explanation : Option [d] “Displacement Reaction” is correct answer.
Class 10 Science Chapter 1 Question 3 :
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer
a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Answer and Explanation : Option [a] “Hydrogen gas and iron chloride are produced” is correct answer.
Class 10 Science Chapter 1 Question 4 :
What is a balanced chemical equation? Why should chemical equations be balanced?
Answer and Explanation :
Balanced Chemical Equation : These are those chemical equation that have equal masses or equal number of atoms on both sides of an equation.
The number of atoms of each element remains same before and after chemical reaction. Therefore, we need to balance a chemical equation so that it obey the law of conservation of mass.
Class 10 Science Chapter 1 Question 5 :
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
Answer and Explanation :
(a) 3H2 + N2 -> 2NH3
(b) 2H2S + 3O2 -> 2SO2 + 2H2O
(c) 3BaCl2 + Al2(SO4)3 -> 2 AlCl3 + 3BaSO4
(d) 2K + 2H2O -> 2KOH + H2 (g)
Class 10 Science Chapter 1 Question 6 :
Balance the following chemical equations.
(a) HNO3 +Ca(OH)2 → Ca(NO3 )2 + H2O
(b) NaOH + H2SO4 → Na2SO4 + H2O
(c) NaCl + AgNO3 → AgCl + NaNO3
(d) BaCl2 + H2SO4 → BaSO4 + HCl
Answer and Explanation :
(a) 2HNO3 +Ca(OH)2 → Ca(NO3 )2 + 2H2O
(b) 2NaOH + H2SO4 → Na2SO4 + 2H2O
(c) NaCl + AgNO3 → AgCl + NaNO3 ( It is already balanced chemical equation.)
(d) BaCl2 + H2SO4 → BaSO4 + 2HCl
Class 10 Science Chapter 1 Question 7 :
Write the balanced chemical equations for the following reactions.
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
Answer and Explanation :
(a) Ca(OH)2 + CO2 -> CaCO3 + H2O
(b) Zn + 2AgNO3 -> Zn(NO3 )2 + 2Ag
(c) 2Al3 + 3CuCl2 -> 2AlCl3 + 3Cu
(d) BaCl2 + K2SO4 -> BaSO4 + 2KCl
Class 10 Science Chapter 1 Question 8 :
Write the balanced chemical equation for the following and identify the type of reaction in each case.
(a) Potassium bromide(aq) + Barium iodide(aq) → Potassium iodide(aq) + Barium bromide(s)
(b) Zinc carbonate(s) → Zinc oxide(s) + Carbon dioxide(g)
(c) Hydrogen(g) + Chlorine(g) → Hydrogen chloride(g)
(d) Magnesium(s) + Hydrochloric acid(aq) → Magnesium chloride(aq) + Hydrogen(g)
Answer and Explanation :
(a) 2KBr + BaI2 -> 2KI + BaBr2
(b) ZnCO3 -> ZnO + CO2
(c) H2 + Cl -> 2HCl
(d) Mg2 +2HCl -> MgCl2 + H2
Class 10 Science Chapter 1 Question 9 :
What does one mean by exothermic and endothermic reactions? Give examples.
Answer and Explanation :
Exothermic Reaction :- Those reaction in which heat is evolved are known as Exothermic Reaction. For example : C+ O2 -> CO2 + Heat
Class 10 Science Chapter 1 Question 10 :
Why is respiration considered an exothermic reaction? Explain.
Answer and Explanation :
Respiration is considered as an exothermic reaction. The carbohydrates are broken down into glucose to give us energy . This whole process evolves heat during digestion.
Class 10 Science Chapter 1 Question 11 :
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions
Answer and Explanation :
This is because in decomposition reaction, a single compound splits up into two or more simpler substances whereas combination reactions are those reactions in which two or more substances combine to forma a single substance. For Example :-
Decomposition Reaction : CaCO3 -> CaO + CO2
Combination Reaction : CaO + H2O -> Ca(OH)2
Class 10 Science Chapter 1 Question 12 :
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity
Answer and Explanation :
CaCo3 + Heat -> CaO + CO2
2H2O + (Electrolysis) -> 2H2 + O2
6CO2 + 12H2O + Sunlight -> C6 H12 O6 + 6H2O + 6O2
Class 10 Science Chapter 1 Question 13 :
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Answer and Explanation :
Displacement Reaction : These are those reaction in which a more reactive metal displaces a less reactive metal. For Example :
CuSO4 + Zn -> ZnSO4 +Cu
Double Displacement Reaction : These are those reaction in which two compounds react by exchange of ions to form two new compounds. For Example :
AgNO3 + NaCl -> AgCl + NaNO3
Class 10 Science Chapter 1 Question 14 :
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved
Answer and Explanation :
2AgNO3 + Cu -> Cu(NO3)2 + 2Ag
Class 10 Science Chapter 1 Question 15 :
What do you mean by a precipitation reaction? Explain by giving examples
Answer and Explanation :
Precipitate Reaction : Any reaction that produces a precipitate is called a Precipitate Reaction. For Example :
Na2SO4 + BaCl2 -> BaSO4 (precipitate) + 2NaCl
Class 10 Science Chapter 1 Question 16 :
Explain the following in terms of gain or loss of oxygen with two examples each.
(a) Oxidation
(b) Reduction
Answer and Explanation :
(a) Oxidation : Addition of O2 (oxygen) to a substance is known as Oxidation. For Example :
CuO + H2 -> Cu +H2O ( Hydrogen is getting oxygen)
(b) Reduction : Reduction of Oxygen from a substance is called Reduction. For Example :
CuO + H2 -> Cu + H2O ( Oxygen is removed from CuO)
Class 10 Science Chapter 1 Question 17 :
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed
Answer and Explanation :
The element is copper and compound is Copper Oxide.
Class 10 Science Chapter 1 Question 18 :
Why do we apply paint on iron articles?
Answer and Explanation :
We apply paint or iron articles to prevent them from rusting.
Class 10 Science Chapter 1 Question 19 :
Oil and fat containing food items are flushed with nitrogen. Why
Answer and Explanation :
Oil and Fat containing food items are flushed with nitrogen because it prevents them from getting oxidised.
Class 10 Science Chapter 1 Question 20 :
Explain the following terms with one example each.
(a) Corrosion
(b) Rancidity
Answer and Explanation :
(a) Corrosion : When a metal is attacked by substances around it such as moisture , acids, etc, it is said to corrode and this process is called Corrosion .
(b) Rancidity : It is a phenomena due to which a substance/food item’s flavour or taste changes because of oxidation.