Chemical Reactions and Equations

NCERT Solutions for Class 10 Science Chapter 1

The Chemical Reactions and Equations chapter explores the fundamental concept of chemical reactions, the transformations of substances into new ones. 

Chemical Reactions:

• A process where one or more substances (reactants) undergo a rearrangement of atoms to form new substances with different properties (products).
• Observable signs of a chemical reaction include:
  • Gas formation (fizzling)
  • Color change
  • Precipitate formation (solid appearing in a liquid)
  • Temperature change (absorption or release of heat)

Types of Chemical Reactions:

• Combination Reaction:  A reaction in which multiple starting materials are used to produce one new product. (e.g., Hydrogen + Oxygen -> Water)
• Decomposition Reaction:A single substance decomposes to form two or more new substances. (e.g., Calcium Carbonate -> Calcium Oxide + Carbon Dioxide)
• Displacement Reaction: One element replaces another in a compound. (e.g., Iron + Copper Sulfate -> Iron Sulfate + Copper)
• Double Displacement Reaction: Two salts react by swapping their charged particles (ions) to create two new salts.. (e.g., Sodium Sulfate + Barium Chloride -> Barium Sulfate + Sodium Chloride)

Balancing Chemical Equations:

• Chemical equations use symbols and formulas to represent a chemical reaction.
• The number of atoms of each element must be equal on both the reactants and products side for a balanced equation.
• Balancing is achieved by adjusting coefficients (small numbers placed before formulas) to represent the relative quantities of reactants and products.

Importance of Chemical Equations:

• Provide a concise way to represent a chemical reaction.
• Help predict the products of a reaction.
• Allow for quantitative calculations involving reactants and products based on their balanced ratios.

Additional Concepts:

• Exothermic vs. Endothermic Reactions: Exothermic reactions release heat, while endothermic reactions absorb heat.
• States of Matter: Understanding the physical states (solid, liquid, gas) of reactants and products is crucial for interpreting equations.
• Law of Conservation of Mass: In a chemical reaction, the total mass of reactants remains equal to the total mass of products (mass is neither created nor destroyed).

Understanding chemical reactions and equations forms the foundation for further studies in chemistry. By mastering these concepts, you can interpret chemical changes, predict outcomes, and solve related problems.

NCERT Solutions for Class 10 Science Chapter 1 : Chemical Reactions and Equations

Questions (Page-6)

1. Why should a magnesium ribbon be cleaned before burning in air ?

Ans : Clean magnesium burns brighter! A dirty ribbon has a layer of magnesium oxide that acts like a fire blanket, slowing the reaction. Cleaning removes this layer for a hotter, brighter burn.

2. Write the balanced equation for the following chemical reactions.

(i) Hydrogen + Chlorine → Hydrogen chloride

(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride

(iii) Sodium + Water → Sodium hydroxide + Hydrogen

Ans : 

(i) Hydrogen + Chlorine → Hydrogen chloride

2H₂ (g) + Cl₂ (g) → 2HCl (g)

(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride

3BaCl₂ (aq) + Al₂(SO₄)₃ (aq) → 3BaSO₄ (s) + 2AlCl₃ (aq)

(iii) Sodium + Water → Sodium hydroxide + Hydrogen

2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g)

3. Write a balanced chemical equation with state symbols for the following reactions :

(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.

(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.

Ans : 

(i) Barium Chloride and Sodium Sulfate

BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)

• BaCl₂(aq): Barium chloride (aqueous solution)
• Na₂SO₄(aq): Sodium sulfate (aqueous solution)
• BaSO₄(s): Barium sulfate (solid – insoluble)
• NaCl(aq): Sodium chloride (aqueous solution)

(ii) Sodium Hydroxide and Hydrochloric Acid

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

• NaOH(aq): Sodium hydroxide (aqueous solution)
• HCl(aq): Hydrochloric acid (aqueous solution)
• NaCl(aq): Sodium chloride (aqueous solution)
• H₂O(l): Water (liquid)

NCERT Solutions for Class 10 Science Chapter 1 : Chemical Reactions and Equations

Questions (Page – 10)

1. A solution of a substance ‘X’ is used for white washing.

(i) Name the substance ‘X’ and write its formula.

(ii) Write the reaction of the substance ‘X’ named in (i) above with water.

Ans : 

(i) The substance ‘X’ used for whitewashing is calcium oxide (CaO). It’s also commonly known as quicklime or burnt lime.

(ii) When calcium oxide reacts with water, it slakes to form calcium hydroxide (Ca(OH)2). The chemical equation is:

CaO(s) + H₂O(l) → Ca(OH)2(aq)

• CaO(s): Calcium oxide (solid)
• H₂O(l): Water (liquid)
• Ca(OH)2(aq): Calcium hydroxide (aqueous solution)

2. Why is the amount of gas collected in one of the test tubes in text book Activity 1.7 (i.e., electrolysis of water) double of the amount collected in the other? Name this gas.

Ans : During the electrolysis of water (Activity 1.7), the gas collected in one test tube will be double the amount collected in the other because of the following reasons:

1. Water Composition: Water (H₂O) is composed of two hydrogen atoms (H) and one oxygen atom (O).
2. Electrolysis Process: Electrolysis breaks down water molecules into their constituent elements – hydrogen and oxygen.
3. Stoichiometry of the Reaction: The balanced chemical equation for the electrolysis of water is:
   2H₂O (l) → 2H₂ (g) + O₂ (g)
   This equation tells us that for every two water molecules (2H₂O) broken down, we get two molecules of hydrogen gas (2H₂) and one molecule of oxygen gas (O₂).

NCERT Solutions for Class 10 Science Chapter 1 : Chemical Reactions and Equations

Questions (Page-13)

1. Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?

Ans : The color of copper sulphate solution changes when an iron nail is dipped in it because of a displacement reaction.

The iron metal from the nail displaces the copper metal from the copper sulphate solution. This means the iron reacts with the copper sulphate, replacing the copper in the compound.

2. Give an example of a double displacement reaction other than the one given in Activity 1.10 

Ans : 

Reaction between Barium Chloride (BaCl₂) and Sodium Sulfate (Na₂SO₄):

This reaction produces Barium Sulfate (BaSO₄) and Sodium Chloride (NaCl).

Balanced Chemical Equation:

BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)

3. Identify the substances that are oxidised and the substances which are reduced in the following reactions.

(i) 4Na(s) + O2(g) → 2Na2O(s)

(ii) CuO (s) + H2(g) → Cu (s) + H2O(l)

Ans : Based on the changes in oxidation states of the elements involved, here’s the breakdown of which substances are oxidized and reduced in the reactions:

(i) 4Na(s) + O2(g) → 2Na2O(s)

• Oxidized: O2(g) (Oxygen)
• Reduced: Na(s) (Sodium)

Explanation:

• Oxygen (O) goes from O² in O₂ to O⁻¹ in Na₂O. A decrease in oxidation state indicates reduction.
• Sodium (Na) goes from 0 in Na to +1 in Na₂O. An increase in oxidation state indicates oxidation.

(ii) CuO (s) + H2(g) → Cu (s) + H2O(l)

• Oxidized: H2(g) (Hydrogen)
• Reduced: CuO(s) (Copper oxide)

Explanation:

• Hydrogen (H) goes from 0 in H₂ to +1 in H₂O. An increase in oxidation state indicates oxidation.
• Copper (Cu) goes from +2 in CuO to 0 in Cu. A decrease in oxidation state indicates reduction.

NCERT Solutions for Class 10 Science Chapter 1 : Chemical Reactions and Equations

Exercises

1. Which of the statements about the reaction below are incorrect ?
2 PbO(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

Ans : (i) (a) and (b)

statement (b) – “Carbon dioxide is getting oxidized” – is incorrect. Carbon dioxide is already in its most oxidized state (+4), and it doesn’t change further in this reaction.

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

Ans : (d) displacement reaction

In this reaction:

• Aluminum (Al) is more reactive than iron (Fe).
• Aluminum displaces iron from ferric oxide (Fe2O3), forming aluminum oxide (Al2O3) and elemental iron (Fe).

3. What happens when dilute hydrochloric acid is added to iron filings ? 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.

Ans : (a) Hydrogen gas and iron chloride are produced.

Here’s why:

• Dilute hydrochloric acid (HCl) is a strong acid, and iron filings (Fe) are a reactive metal.
• When these two react, a single displacement reaction occurs. Iron displaces hydrogen from the hydrochloric acid.
• The products of this reaction are hydrogen gas (H₂) and iron chloride (FeCl₂).

4. What is a balanced chemical equation ? Why should chemical equations be balanced ?

Ans : A balanced chemical equation is a symbolic representation of a chemical reaction that follows the Law of Conservation of Mass.

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.

Ans : 

a) Balanced equation:  N₂ (g) + 3H₂ (g) → 2NH₃ (g)

• Nitrogen (N₂) reacts with hydrogen (H₂) to produce ammonia (NH₃).

(b)Balanced equation:  2H₂S (g) + 3O₂ (g) → 2H₂O (l) + 2SO₂ (g)

• Hydrogen sulfide (H₂S) reacts with oxygen (O₂) to produce water (H₂O) and sulfur dioxide (SO₂).

(c)Balanced equation:  3BaCl₂ (aq) + Al₂(SO₄)₃ (aq) → 2AlCl₃ (aq) + 3BaSO₄ (s)

• Barium chloride (BaCl₂) reacts with aluminum sulfate (Al₂(SO₄)₃) to produce aluminum chloride (AlCl₃) and barium sulfate (BaSO₄) as a precipitate (solid).

(d) Balanced equation:  2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g)

• Potassium (K) reacts with water (H₂O) to produce potassium hydroxide (KOH) and hydrogen gas (H₂).

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

Ans : 

(a) HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + H₂O  (Already Balanced)

This equation is already balanced. There are one N atom, three H atoms, one Ca atom, and three O atoms on both sides of the reaction.

(b) NaOH + H₂SO₄ → Na₂SO₄ + H₂O

Balanced equation: 2NaOH (aq) + H₂SO₄ (aq) → Na₂SO₄ (aq) + 2H₂O (l)

We need a coefficient of 2 in front of NaOH to balance both Na and H atoms.

(c) NaCl + AgNO₃ → AgCl + NaNO₃

Balanced equation: NaCl (aq) + AgNO₃ (aq) → AgCl (s) + NaNO₃ (aq)

This equation is already balanced. There is one Na atom, one Cl atom, one Ag atom, and three O atoms on both sides of the reaction.

(d) BaCl₂ + H₂SO₄ → BaSO₄ + HCl

Balanced equation: BaCl₂ (aq) + H₂SO₄ (aq) → BaSO₄ (s) + 2HCl (aq)

We need a coefficient of 2 in front of HCl to balance both Cl atoms.

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

Ans : 

(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water

Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l)

(b) Zinc + Silver nitrate → Zinc nitrate + Silver

Zn(s) + 2AgNO₃(aq) → Zn(NO₃)₂(aq) + 2Ag(s)

(c) Aluminium + Copper chloride → Aluminium chloride + Copper

2Al(s) + 3CuCl₂(aq) → 2AlCl₃(aq) + 3Cu(s)

(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride

BaCl₂(aq) + K₂SO₄(aq) → BaSO₄(s) + 2KCl(aq)

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

(b) Zinc carbonate(s) → Zinc oxide (s) + Carbon dioxide (g) bromide(s)

(c) Hydrogen (g) + Chloride (g) → Hydrogen chloride (g)

(d) Magnesium (s) + Hydrochloric acid (aq) → Magnesium chloride (aq) + Hydrogen       (g)

Ans : 

(a) Potassium bromide (aq) + Barium iodide (aq) → Potassium iodide (aq) + Barium bromide (s)

• Balanced Equation: 2KBr(aq) + BaI₂(aq) → 2KI(aq) + BaBr₂(s)
• Type of Reaction: Double Displacement Reaction

In this reaction, the cations (positive ions) of the ionic compounds swap places. Potassium (K⁺) from KBr replaces Barium (Ba²⁺) in BaI₂, and Barium (Ba²⁺) takes the place of Potassium (K⁺) in KBr. This results in the formation of two new ionic compounds, potassium iodide (KI) and barium bromide (BaBr₂).

(b) Zinc carbonate(s) → Zinc oxide (s) + Carbon dioxide (g)

• Balanced Equation: ZnCO₃(s) → ZnO(s) + CO₂(g)
• Type of Reaction: Decomposition Reaction

Here, a single compound (zinc carbonate, ZnCO₃) breaks down into two simpler substances: zinc oxide (ZnO) and carbon dioxide (CO₂).

(c) Hydrogen (g) + Chlorine (g) → Hydrogen chloride (g)

• Balanced Equation: H₂(g) + Cl₂(g) → 2HCl(g)
• Type of Reaction: Combination Reaction

Two elements (hydrogen, H, and chlorine, Cl) combine to form a single product, hydrogen chloride (HCl).

(d) Magnesium (s) + Hydrochloric acid (aq) → Magnesium chloride (aq) + Hydrogen (g)

• Balanced Equation: Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
• Type of Reaction: Single Displacement Reaction (Also called Replacement Reaction)

9. What does one mean by exothermic and endothermic reactions ? Give examples.

Ans : 

Exothermic Reaction:

• Meaning: In an exothermic reaction, energy is released from the system (reactants and products) to the surroundings. This means the reaction releases heat, making the surrounding environment warmer.
• Example:
  • Burning of wood: When wood burns (cellulose reacts with oxygen), a large amount of heat and light energy is released. This is why burning wood can be used as a heat source
  • C (s) + O2 (g) → CO2 (g) + Heat

Endothermic Reaction:

• Meaning: In an endothermic reaction, energy is absorbed from the surroundings by the system. This means the reaction absorbs heat, making the surrounding environment cooler.
• Example:
  • Dissolving ammonium nitrate in water: When ammonium nitrate (NH₄NO₃) dissolves in water, it absorbs heat from the surrounding solution, causing the temperature to drop. This is why ammonium nitrate is sometimes used in cold packs.
  • C (s) + 2S (s) → CS2 (l) – Heat

10. Why is respiration considered an exothermic reaction ? Explain.

Ans : Respiration burns glucose for energy (ATP) like burning a candle.  This releases heat, making it an exothermic reaction and warming your body. Not all the energy goes towards heat, but some does, keeping you warm.

The simplified equation for cellular respiration is:

C₆H₁₂O₆ (g) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (l) + energy (ATP)

11. Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.

Ans : Decomposition reactions are called the opposite of combination reactions because they involve the breakdown of a single, more complex compound into two or more simpler substances. In contrast, combination reactions involve the joining of two or more elements or compounds to form a single product.

Here’s why they’re opposites:

• Decomposition: Breaks down one compound (AB) into simpler products (A and B).
• Combination: Combines two or more elements/compounds (A and B) into a single product (AB).

Examples:

• Decomposition:
  • Calcium carbonate (CaCO₃) decomposes with heat to form calcium oxide (CaO) and carbon dioxide (CO₂).
• Equation: CaCO₃(s) → CaO(s) + CO₂(g)
• Combination:
  • Hydrogen gas (H₂) and oxygen gas (O₂) combine to form water (H₂O).
• Equation: 2H₂(g) + O₂(g) → 2H₂O(l)

12. Write one equation each for the decomposition reactions where energy is supplied in the form of heat, light or electricity.

Ans : 

Heat:

• Calcium carbonate decomposes with heat to form calcium oxide and carbon dioxide:
  CaCO₃(s) + heat → CaO(s) + CO₂(g)

Light:

• Silver chloride decomposes with light to form silver metal and chlorine gas:
  2AgCl(s) + light → 2Ag(s) + Cl₂(g)

Electricity:

• Water decomposes with electricity (electrolysis) to form hydrogen gas and oxygen gas:
  2H₂O(l) + electricity → 2H₂(g) + O₂(g)

13. What is the difference between displacement and double displacement reactions? Write equations for these reactions.

Ans : Both displacement and double displacement reactions involve replacing one element or ion with another, but they differ in the number of replacements that occur.

Displacement Reaction (Single Replacement):

• A more reactive element displaces a less reactive element from its compound.
• Only one element or ion is replaced.

Example:

Iron (Fe) displaces copper (Cu) from copper sulfate (CuSO₄) to form iron sulfate (FeSO₄) and copper metal (Cu).

Equation: Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s)

Double Displacement Reaction:

• Ions from two different ionic compounds exchange places to form two new ionic compounds.
• Two replacements occur (one cation and one anion).

Example:

Sodium chloride (NaCl) reacts with silver nitrate (AgNO₃) to form sodium nitrate (NaNO₃) and silver chloride (AgCl).

Equation: NaCl(aq) + AgNO₃(aq) → NaNO₃(aq) + AgCl(s)

14. In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.

Ans : The reaction involved in the refining of silver using copper metal displacement is:

2AgNO₃(aq) + Cu(s) → 2Ag(s) + Cu(NO₃)₂(aq)

Here’s a breakdown of the reaction:

• Reactants:
  • Silver nitrate (AgNO₃) – dissolved in water (aq)
  • Copper metal (Cu) – solid (s)
• Products:
  • Silver metal (Ag) – precipitates as a solid (s)
  • Copper nitrate (Cu(NO₃)₂) – remains dissolved in the solution (aq)

15. What do you mean by a precipitation reaction ? Explain by giving examples.

Ans : A precipitation reaction is a chemical reaction occurring in an aqueous solution (a solution where water is the solvent) that forms an insoluble solid product called a precipitate. These reactions typically involve the exchange of ions between two dissolved ionic compounds.

Examples of Precipitation Reactions:

1. Silver Nitrate (AgNO₃) and Sodium Chloride (NaCl):

• Equation: NaCl(aq) + AgNO₃(aq) → NaNO₃(aq) + AgCl(s)

2. Barium Chloride (BaCl₂) and Potassium Sulfate (K₂SO₄):

• Equation: BaCl₂(aq) + K₂SO₄(aq) → BaSO₄(s) + 2KCl(aq)

16. Explain the following in terms of gain or loss of oxygen with two examples each:

(a) Oxidation and

(b) Reduction.

Ans : 

(a) Oxidation:

• Definition: Involves a loss of electrons or an increase in oxidation number. However, a more general definition used to understand the concept is loss of oxygen.

Examples (considering loss of oxygen):

1. Burning of Magnesium:
   • Reaction: 2Mg(s) + O₂(g) → 2MgO(s)
   • Explanation: Magnesium metal (Mg) loses oxygen to form magnesium oxide (MgO).

(b) Reduction:

• Definition: Involves a gain of electrons or a decrease in oxidation number. Here, we’ll focus on the general definition of gain of oxygen.

Examples (considering gain of oxygen):

1. Heating Copper Oxide with Hydrogen:
   • Reaction: CuO(s) + H₂(g) → Cu(s) + H₂O(l)
   • Explanation: Copper oxide (CuO) gains oxygen from hydrogen (H₂) to form copper metal (Cu). While hydrogen technically loses electrons, here we’re focusing on the concept of gaining oxygen.

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.

Ans : 

The element ‘X’ is most likely copper (Cu).

Here’s why:

• Shiny brown color: Copper is well-known for its characteristic shiny brown appearance.
• Blackens on heating: When copper metal (Cu) is heated in air (which contains oxygen, O₂), it reacts with the oxygen to form a black-colored compound called copper oxide (CuO).

Reaction:

2Cu(s) + O₂(g) → 2CuO(s)

Therefore, element ‘X’ is copper (Cu), and the black colored compound formed is copper oxide (CuO).

18. Why do we apply paint on iron articles ?

Ans : We paint iron to prevent rust. Paint acts as a barrier, stopping oxygen and moisture in the air from reaching the iron and causing it to rust. This keeps your iron articles strong and shiny!

19. Oil and fat containing food items are flushed with nitrogen. Why ?

Ans : Foods with oil and fat get nitrogen gas flushed in them to prevent spoilage. Nitrogen pushes out oxygen, which can make the fats and oils go bad (rancid) faster. Basically, nitrogen acts like a shield to keep the food fresh for longer.

20. Explain the following terms with one example each (a) Corrosion, (b) Rancidity.

Ans : 

(a) Corrosion: The deterioration of metals due to their reaction with air, moisture, or other substances.

• Example: Iron rusting. When exposed to air and moisture, iron reacts to form a reddish-brown flaky substance called rust (iron oxide), weakening the metal.

(b) Rancidity: The process where fats and oils in food spoil, developing an unpleasant odor and taste.

• Example: Spoiled nuts or potato chips. Over time, the fats and oils in these foods can react with oxygen in the air, leading to rancidity and an off flavor.

NCERT Solutions for Class 10 Science Chapter 1 : Chemical Reactions and Equations

FAQs

What is the main focus of NCERT Solutions for Class 10 Science Chapter 1?

The main focus of NCERT Solutions for Class 10 Science Chapter 1 is to explain the fundamentals of chemical reactions and equations, including how to write and balance them.

How are chemical reactions defined in Class 10 Science Chapter 1?

In Class 10 Science Chapter 1, chemical reactions are defined as processes in which one or more substances, called reactants, are transformed into new substances, known as products, with different properties.

What are the different types of chemical reactions discussed in NCERT Solutions for Class 10 Science Chapter 1?

NCERT Solutions for Class 10 Science Chapter 1 discuss different types of chemical reactions, including combination reactions, decomposition reactions, displacement reactions, double displacement reactions, and redox reactions.

How can you identify a chemical reaction according to Class 10 Science Chapter 1?

According to Class 10 Science Chapter 1, a chemical reaction can be identified by changes such as the formation of a precipitate, change in color, evolution of gas, and change in temperature or energy.

What is a balanced chemical equation as explained in NCERT Solutions for Class 10 Science Chapter 1?

A balanced chemical equation, as explained in NCERT Solutions for Class 10 Science Chapter 1, has an equal number of atoms of each element on both sides of the equation, ensuring the law of conservation of mass is satisfied.

Why is it important to balance chemical equations in Class 10 Science Chapter 1?

Balancing chemical equations in Class 10 Science Chapter 1 is crucial to accurately represent the quantities of reactants and products involved in a chemical reaction, adhering to the law of conservation of mass.

What is a combination reaction according to NCERT Solutions for Class 10 Science Chapter 1?

According to NCERT Solutions for Class 10 Science Chapter 1, a combination reaction is a type of chemical reaction where two or more substances combine to form a single product.

What are displacement reactions as discussed in Class 10 Science Chapter 1?

Displacement reactions, as discussed in Class 10 Science Chapter 1, are chemical reactions in which an element displaces another element from its compound, typically involving metals and their compounds.

How are decomposition reactions defined in NCERT Solutions for Class 10 Science Chapter 1?

Decomposition reactions, as defined in NCERT Solutions for Class 10 Science Chapter 1, involve the breaking down of a single compound into two or more simpler substances, often requiring heat, light, or electricity.

What is the significance of redox reactions in Class 10 Science Chapter 1?

The significance of redox reactions in Class 10 Science Chapter 1 lies in their involvement in the transfer of electrons between substances, encompassing both oxidation and reduction processes, which are fundamental to many chemical reactions.