Extra Question Answers Class 10th Ch-1 (Chemical Reaction and Equations).

Extra Question Answers Class 10th Ch-1 (Chemical Reaction and Equations).
Extra Question Answers Class 10th Ch-1 (Chemical Reaction and Equations).

Extra Question Answers Class 10th Ch-1: After Completing NCERT Question/Answers it is very Compulsory to learn the Extra Questions of that particular Chapter Especially in Science. Because you know NCERT is not very Sufficient to score higher marks in Exams, If you haven’t Completed any (i). Extra Book (ii). Any Extra sample paper or (iii). Past year Question paper.

So students let’s start with Very short Question Answers.

Very Short Extra Question Answers Class 10th Ch-1

Q1). What changes do you observe in Iron anils and colors of copper sulphate solution, If the iron nail is dipped in CuSO4 solution for 15 Minutes?

Ans:- When the Iron nail is dipped in the CuSO4(Copper sulphate) Solution for 15 minutes then, the blue color of the Copper Sulphate solution will change to Fade. Because Fe will replace Cu from CuSO4 (Because Fe is more reactive than the Cu.) to form FeSO4(Iron sulfate).

Q2). Identify the chemical Change: Melting of Ice or Conversion of Milk into Curd?

Ans:- Conversion of Milk into Curd is a Chemical change.

Q3). Why is respiration considered an Exothermic reaction?

Ans:- Respiration is considered as an Exothermic Reaction because heat is released in the form of Energy.

C6H12O6(aq) + 6O2(aq) → 6CO2(aq) + 6H2O(l) + energy.
The Glucose combines with oxygen in the cells of our body and gives us Energy. The Reaction is known as respiration.

Q4). Why do copper vessel loses shine when Exposed to air?

Ans:- Because when copper is exposed to air it gets reacts with the Oxygen present in the Atmosphere and forms a Layer of CuO(Copper oxide) on their Surface.

Q5). Potato chips manufacturers fill the packet of chips with nitrogen gas. Why?

Ans:- Because Potato chips Contain Oil and Fat, that’s why when we left potato chips in the air then it will react with oxygen and Become rancid. To save it from rancidity we fill the packet with the Nitrogen gas(Because nitrogen is very less reactive in nature.).

Q6). Why we store Silver Chloride in dark-colored Bottle?

Ans:- Because Silver chloride is a Photolyotic decomposing material that’s why we store Silver chloride in a dark-colored bottle.

Q7). Write the chemical Equation of Double Displacement Reaction?

Ans:- 1). AgNO3 + NaCl → AgCl + NaNO3 , 2). BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq)

Q8). N2 + 3H2—–> 2NH3. name the type of reaction?

Ans:- This is a type of combination reaction and also of Exothermic reaction because heat is also released during this reaction.

Q9). What happens when milk is left open at room temperature during Summer?

Ans:- When milk left at room temperature in summer, then the oxidation of Milk takes place and also Increases in the growth of Microorganisms that results in the Sour taste of Milk.

Q10). What happens when Quick lime is added to water?

Ans:- When Quick lime will be added to the water then Slaked lime will form and also the heat will Evolve.

Q11). Why the Combustion of LPG is a Chemical Reaction?

Ans:- Combustion of LPG is a Chemical Reaction because new substances are formed. CO2 and H2O produced when LPG gas burns.

Q12). What is meant by the skeletal Chemical equation?

Ans:- Unbalanced Chemical Reaction is also known as Skeletal Chemical Reaction.

Q13). What do you observe when Magnesium Ribbon is Burnt?

Ans:- When magnesium ribbon is Burn, you Observe that when Magnesium ribbon burns a white Dazzling flame and white color of MgO (magnesium oxide) will Produce.

Q14). Why photosynthesis is considered as an Endothermic reaction?

Ans:- Photosynthesis is Considers an Endothermic Reaction because heat is absorbed during Photosynthesis in the form of Sunlight.

Q15). Why is hydrogen peroxide kept in the colored bottle?

Ans:- Because H2O2(Hydrogen peroxide) is a Photolyotic decomposing material and when it will come in the Direct cont with the Sunlight then it will decompose into H2O and O2.

Q16). Give one Example of Combustion Reaction which is also Exothermic Reaction?

Ans:- CaO(s) + H2O(l) → Ca(OH)2(aq) + heat

Q17). What type of reaction is Represented by the digestion of food in our Body?

Ans:- Decomposition Reaction.

Q18). What is Raincidity?

Ans:- The oxidation of oil and Fat containing food, which results in the bad taste and smell of the food is known as rancidity.

Q19). Name any two Anti-Oxidants?

Ans:- BHT(Butylated hydrox tonule) BHA(Butylated hydroxy Anisole).

Q20). Define corrosion?

Ans:- It is a natural process of degradation of the metals, OR Oxidation of metal is Known as Corrosion.

Short Questions/Answers (Ch-1) Chemical Reaction and Equations

Note: No any NCERT Exemplar Problem is there in this Extra Question answers there is a Separate category for ncert Exemplar.

If you want to download NCERT Exemplar Book or NCERT CH-1 then just hover and click on the given blue color of the link.

Q1). Define Combination Reaction. Give one example of a combination reaction that is Exothermic in nature?

Ans:- Combination Reaction is a type of reaction in which two or more elements or compounds react together to form one Compound.

Example:- CaO + H2O —-> Ca(OH)2 + heat

Q2). What is Decomposition Reaction? Explain with an example?

Ans:- This Reaction is fully opposite of Combination Reaction Because this is a type of reaction in which Single compound decomposes/breaks into two or more compounds.

Example:- 2 H2O2 → 2 H2O + O2 , NaCl —-> Na + Cl2

Q3). Name and state the law which is kept in mind when we balance a Chemical Equation?

Ans:- Law of conservation of Mass and Law of Constant proportion.

Law of Conservation of Mass:- This law was given by Antonie Lavosiver, This law states that mass can neither be created nor be destroyed in ant=y Chemical Reaction.

Law of Constant proportion:- This law was given by Joseph Louis Proust, This law states that the proportion of atoms/molecules of elements will always be fixed of any Compound. Example:- Take water from anywhere the atoms of the elements will be same (H2O)

Q4). Give one example of each:

  1. Chemical reaction Showing Evolution of gas.
  2. Change in substance’s color during chemical Reaction.

Ans:- (1). Zn + H2SO4 —> ZnSO4 + H2 (This is also an Example of Displacement Reaction and Exothermic Reaction.)

(2). Fe + CuSO4(Blue) —-> FeSO4(green) + Cu, This can also be an Example of Displacement Reaction.

Q5). What is rancidity? Write two ways by which it can be prevented.

Ans:- The Oxidation of fat and Oil containing food, which causes the bad smell and taste is known as Raincidity.

Rancidity can be prevented by the following ways:-

  1. Refrigerator
  2. Using Antioxidants (BHT, BHA)
  3. By Nitrogen packaging.
  4. By Aluminum Packing.

Q6). What are the two conditions which promote Corrosion?

Ans:- Rainy Season, Humidity in the Environment, Presence of Carbon dioxide and other pollutants like Sulfur, Chlorides cause Corrosion.

Q7). A small amount of ferrous Sulphate is heated in a hard glass tube.

  1. Write the chemical Equation.
  2. what types of reactions taking place.

Ans:- (1). 2FeSO4(s) ⎯-→ Fe2O3(s) + SO2(g) + SO3(g) , Iron sulphate will Break down into Iron Oxide, Sulphur dioxide and Sulphur trioxide. (2). This is a type of thermal decomposition Reaction.

Q8). What happened when the Zn strip is dipped in CuSO4 Solution?

Ans:- Because Zn is more Reactive than the Copper that’s why Zn will replace Cu from CuSO4 and forms ZnSO4.

Zn + CuSO4 —> ZnSO4 + Cu

Q9). Which among the following are physical or Chemical change?

  1. Evaporation of petrol.
  2. Burning of LPG.
  3. Heating of an Iron rod.
  4. Curding of Milk.
  5. Sublimation of solid Ammonium Chloride.

Ans:- 1. Evaporation of Petrol is a Physical Change.

2. Burning of LPG is a Chemical Change.

3. Heating of Iron Rod is a Physical Change.

4. Curding of Milk is a Chemical Change.

5. Sublimation of Ammonium Chloride is a Physical Change.

Q10). How do we come to know that chemical Reaction has taken place?

Ans:- These are some following factors that decide either the chemical reaction has taken place or not.

  1. Change in State.
  2. Change in color.
  3. change in gas.
  4. Formation Of precipitate.
  5. Evolution of gas.
  6. Any change in temperature.

Q11). What is an Oxidation reaction? Give an Example of the Oxidation reaction. Is Oxidation an Exothermic or an Endothermic reaction?

Ans:- Oxidation Reaction is a Type of Reaction in which any Element combines with Oxigen to make it’s most Stable compound that is its Oxide. Example:- Magnesium Combines with the oxygen to form MgO, Similarly, Fe Combines with oxygen to form fe2O3 or Fe3O4.

Q12). What is the role of a catalyst in a Chemical reaction?

Ans:- Catalyst is any Element or Compound that Increases or decreases the rate of any chemical Reaction. Example:-

Short (type-II) Extra Question Answers Class 10th Ch-1 [3 Marks]

Q1). What is Redox Reaction? Write down the Chemical reaction representing it.

Ans:- Redox Reaction is a type of reaction in which the oxidation reaction and the reduction reaction takes place Simontiniously. Example:- MnO2 + 4hCl —> MnCl2 + 2H2O + Cl2

Q2). In Electrolysis of water :

  1. Name the gas collected at cathode and anode.
  2. Why is the volume of one gas collected at the one Electrode is double of Another?
  3. Why are the few drops of Dilute H2SO4 added to water?

Ans:- 1). At the cathode the hydrogen gas will be Collected, whereas On Anode Electrode the Oxygen gas will be Collected.

2). The gas collected at the one End of the electrode is double Because you know, H2O (Water) contains two atoms of hydrogen in one molecule of water that’s why the gas collected at the one Electrode is double than the Another.

3). To make the Solution Acidic so that the Electricity can pass easily through the Reaction.

Q3). In the Reaction:

CuO(s) + H2(g) ———> Cu(s) + H20 (g)

  1. Name the Oxidized Substance.
  2. Name the reduced Substance.
  3. Name the Oxidizing Agent.

Ans:- 1). Hydrogen is oxidizing to form H2O (water).

2). CuO (Copper Oxide) reduced to Cu(Copper).

3). CuO (Copper oxide) is an Oxidising Agent because it reduces itself to oxidize others.

Q4). Give Reasons:

  1. White Silver chloride turns grey in sunlight.
  2. Brown Coloured copper powder on heating in the air turns into black colored Substance.

Ans:- White Silver Chloride turns grey in Sunlight, Because Silver Chloride is a Photolyptic Decomposing Material and when we kept AgCl in the Sunlight then it Decomposes to form Silver, That’s why the color of Agcl converted to the grey.

2). When the brown color of Copper powered on Heated in Air turns into Black color because On heating in the presence of air Cu reacts with the Oxygen present in the air. Cu + O2 —-> CuO (Copper Oxide).

Q5). Compound ‘X’ decomposes to form compound ‘Y’ and CO2 gas. Compound Y is used in the manufacturing of Element.

  1. Name the Compounds ‘X’ & ‘Y’ .
  2. Write the Chemical equation for this Reaction.

Ans:- 1). Compound ‘X’ is CaCO3 (Calcium carbonate) and compound ‘Y’ is CaO(Calcium oxide) which is used as a manufacturing Element in Cement.

2). CaCO3(Calcium carbonate) ----> CaO(Calcium Oxide) + CO2

Extra Question Answers Class 10th Ch-1 Q6.

Ans:- 1). Metal M is Ag(Silver), Whereas gas X2 is Chlorine gas.

2). The metal Salt MX is AgCl (Silver Chloride).

3). 2AgCl(s) ⎯→ 2Ag(s) + Cl2(g)

Extra Question Answers Class 10th Ch-1 Q7.

Ans:- 1). Metal ‘X’ is Zinc and Metal ‘Y’ is Copper.

2). YSO4–> CuSO4 (Blue in color)

3). The above example is an example of a Single Displacement reaction. Ex:- Zn + CuSO4(Blue color) —–> ZnSO4 + Cu

Extra Question Answers Class 10th Ch-1 Q8.

Ans:- 1). Pb(NO3)2 + H2SO4 —–> PbSO4(PPt.) + 2HNO3

2). 3Mg(s) + N2(g) —–> Mg3N2(s)

3). 2Al(s) + 6HCl (aq) —–> 2AlCl3(aq) + 3H2(g)

Q9). Name the type of chemical Reactions Represented by the following Equation.

  1. CaO + H2O —–> Ca(OH)2
  2. 3BaCl2 + Al2(SO4)3 ——-> AlCl3 + 3BaSO4
  3. 2FeSO4 ——–> Fe203 SO2+ SO3

Ans:- 1). This is a type of Combination Reaction.

2). This is a type of Double Displacement Reaction.

3). This is a type of Thermal Decomposition Reaction.

Extra Question Answers Class 10th Ch-1 Q10.

Q10). Translate the following statements into chemical equations and then balance the Equations:

  1. Phosphorus burns in oxygen to give phosphorus Pentaoxide.
  2. Aluminum metal replaces iron from ferric Oxide, Fe2O3, giving Aliminium oxide and Iron.
  3. Carbon disulfide burns in air to give carbon dioxide and sulfur dioxide.
  4. Barium chloride reacts with zinc sulfate to give zinc chloride and barium sulfate.

Ans:- 1). P4 + 5O2 —–> 2P2O5

2). 2Al + Fe2O3 ——> Al2O3 + Fe

3). CS2 + 3O2 —-> CO2 + 2SO2

4). BaCl2 + ZnSO4 —–> ZnCl2 + BaSO4

Q11). Solid calcium oxide was taken in a container and water was added slowly to it.

  1. State the two observations made in the Experiment.
  2. Write the name and chemical formulas of the product formed.

Ans:- 1). Here is the following Observation:

a). Calcium oxide(CaO) will reacts vigorously with the water to form Ca(OH)2 (Slaked Lime)

b). The heat will release during this reaction Because this is a type of Exothermic Reaction.

(2). When Quick Lime/Calcium oxide(CaO) will React with the water then Slakes lime will form. Cao + H2O —> Ca(OH)2 + Heat.

Q12). Identify the type of reaction in the following Examples:

  1. Na2SO4 + BaCl2 —–> BaSO4 + NaCl
  2. Fe + CuSO4 —-> FeSO4 + Cu
  3. 2H2 + O2 —–> 2H2O

Ans: 1). This is a type of Double displacement and Precipitation Reaction.

2). This is a type of Single Displacement Reaction.

3). This is a type of Combination Reaction.

Q13). What is Balanced Chemical Equation? Why chemical Equation Should Balanced?

Ans:- Any type of reaction in which the no. of atoms present at the Reactant side is equal to the no. of Atoms present at the Product side.

The Chemical Reaction should be balanced, To satisfy the law of Conservation of mass and Law of Constant Proportion.

Q14). Write 3 equations for decomposition Reaction where Energy is supplied in the form of Heat, Light, and Electricity?

Ans:- The 3 Equations for the Decomposition Reaction in which th e Energy is supplied in 3 Different forms are:-

1). Thermal Decomposition Reaction:

2FeSO4(s) ⎯ → ⎯⎯⎯ Heat Fe2O3(s) + SO2(g) + SO3(g)

2). Electrolyte Decomposition reaction:-

H2O(l) —–> H2(g) + O2(g)

3). Photolytic Decomposition Reaction:-

2AgCl(s) —-> 2Ag(s) + Cl2(g)

Q15). What are Neutralisation Reactions? Why are they named so? Give one example?

Ans:- This is a type of reaction in which the Acid and Bases react with each other to form Salt and Water. Eg:- HCl + NaOH —-> NaCl + H2O

Q16). Define Rusting? Why do you apply paint to an iron Article?

Ans:- The Oxidation of Iron is called Rusting. We apply the paint on the iron article to Cut down the Presence of air/Oxygen from the Atmosphere so that we can save this from Rusting.

Long Extra Question Answers Class 10th Ch-1 [5-Marks]

Q1). What types of reaction are represented by following:

  1. CaCO3 —> CaO + CO2
  2. 2Ca + O2 —-> 2CaO
  3. Pb + CuCl2 —-> PbCl2 + Cu
  4. 2FeSO4 —-> Fe2O3 + SO2 + SO3
  5. Na2SO4 + BaCl2 —> BaCl2 + 2NaCl

Ans:- 1. Thermal decomposition Reaction.

  1. Thermal Decomposition Reaction.
  2. Combination Reaction.
  3. Single Displacement Reaction.
  4. Decomposition Reaction.
  5. Double Displacement reaction

Q3). Balance the following Equations:

  1. H2 + O2 —> H2O
  2. MnO2 + HCl —> MnCl2 + H2O + Cl2
  3. Pb(NO3)2 —–> PbO + NO2 + O2
  4. AgNO3 + NaCl —> AgCl + NaNO3
  5. Ca(OH)2 + HNO3 —> Ca(NO3)2 + H2O

Ans:- 2H2 + O2 —-> 2H2O

  1. 2H2 + O2 —-> 2H2O
  2. MnO2 + 4HCl —> MnCl2 + 2H2O + Cl2
  3. 2Pb(NO3)2 —–> 2PbO + 4NO2 + O2
  4. AgNO3 + NaCl —> AgCl + NaNO3 (already balanced)
  5. Ca(OH)2 + 2HNO3 —> Ca(NO3)2 + 2H2O
Extra Question Answers Class 10th Ch-1 Q4.


  1. 2AgCl —–> 2Ag + Cl2
  2. Cao + H20 —–> Ca(OH)2 + Heat
  3. NaOH + HCl —-> NaCl + H2O (Already Balanced)
  4. HCl + CuO —> CuCl2 + H2O
  5. BaCl2 + Na2SO4 —-> BaSO4 + NaCl

HOTS Question/Answer:-

Extra Question Answers Class 10th Ch-1 Q1.

Ans:- In this Reaction, the blackness of the compound (Ag2S) Silver Sulphide is because when silver was exposed to the Air then it Reacts with the Sulphur gas present in the Atmosphere to form a thin layer of Silver Sulphide on its surface.

Again, when we put the Silver coin with the aluminum in the presence of hot water. then a new reaction takes place and Alimunium replaces the Ag (Silver) from Ag2S to form Al2S3(Aluminium Sulphide). 3AgS + 2Al —> 6Ag + Al2S3.

That’s why the silver coin starts shining again.

Q2. During the Electrolysis of water, a few drops of H2SO4 are added into water. Why?

Ans:- To make the water a good Conductor of electricity we add a little amount of Sulphuric acid (H2SO4) so that the electricity can pass through the Solution.

Extra Question Answers Class 10th Ch-1 Q4.

Ans:- CaO + H2O —> Ca(OH)2 + Heat.

Compound ‘A’ is CaO (Calcium oxide), Whereas, Compound ‘B’ is Ca(OH)2.

Ca(OH)2(aq) + CO2(g) ——> CaCO3(s) + H2O(l),

‘C’ is CaCO3.

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