ICSE CHEMISTRY 2025 Last minute Suggestions

Stuck on periodic properties, chemical bonding, or the nuances of organic chemistry? Battling the daunting realm of electrolysis and metallurgy? Worry not, ICSE 2025 chemistry candidates! This in-depth guide is your go-to last-minute study aid, created to reinforce your knowledge and give you that confidence boost in the exam. We will tackle the fundamentals, from memorizing the first 20 elements and valence electrons to acing the Contact Process and Ostwald’s Process.

Get ready to master acid-base reactions, grasp pH, and read indicator colors such as litmus, methyl orange, and phenolphthalein. We will approach analytical chemistry with precipitates generated by NaOH and NH4OH, as well as delve into the amphoteric properties of significant metals. Grasp mole concept and stoichiometry, including Gay-Lussac’s Law and Avogadro’s number, and become skilled at computing empirical and molecular formulas.

Demystify electrolysis by learning cathode and anode reactions, electrolyte action, and the key factors influencing discharge of ions. We will learn electroplating with nickel and silver, and electrorefining copper. Discover the world of metallurgy, such as roasting, calcination, and extraction of iron, aluminum, and zinc from their ores. Learn key reducing agents and the complexities of Baeyer’s and Hall-Héroult processes.

Finally, lab preparation, physical properties, and chemical reactions of important inorganic compounds such as hydrogen chloride, ammonia, nitric acid, and sulfuric acid are explained. For organic chemistry, we’ll look into catenation, isomerism, homologous series, nomenclature, preparation, and reaction of methane, ethane, ethene, ethyne, and ethanol with the synthesis of glacial acetic acid. This is your one-stop manual for ICSE Chemistry 2025 success!

1. Encourage students to read all options carefully to eliminate incorrect ones while answering.
2. Instruct students to read questions carefully and pay attention to bold or italicized words.
3. Emphasize teaching through practical experiments to help students retain facts more easily.
4. Encourage experimental learning to help students recognize and recall lab observations.
5. Provide adequate revision of observation-based questions, especially those involving colors and precipitates.
6. Emphasize the identification of gases by smell and color and provide regular objective tests to avoid mistakes.
7. Discourage guesswork and encourage solving problems to arrive at the correct answer.
8. Ensure students learn correct definitions with key words.
9. Conduct periodic tests to assess student understanding of this concept.
10. Guide students to read questions properly and answer accordingly.
11. Train students to write chemical equations with necessary conditions.
12. Provide various metals for practice on equations and gas formation based on this concept.
13. Teach the gases formed from reactions, especially with ammonia and other acidic gases, and explain their nature, state, and properties using a table.
14. Provide practice of all processes involved according to the syllabus, creating a table to differentiate processes by name, reactants, products, catalyst, and special conditions.
15. Conduct constant drilling to prevent confusion.
16. Train students with correct definitions containing all keywords and encourage them to write complete sentences for each definition to convey a complete meaning.
17. Advise students to write clear chemical reactions, noting gases formed and necessary conditions.
18. Guide students to read questions carefully and analyze answers appropriately.
19. Discuss the impact of chemicals in daily life, explaining terms with relevant examples.
20. Provide frequent short tests and worksheets with equations to analyze student skills.
21. Provide ample practice for correct differentiation in assessments.
22. Explain the reaction with observations and equations to clarify the process.
23. Provide regular practice on questions related to these elements to reinforce learning.
24. Emphasize the importance of reading questions and instructions carefully and writing correct symbols.
25. Provide sequential practice questions with different criteria to reinforce understanding.
26. Provide more practice with different examples to help students understand and correctly answer these types of questions.
27. Insist on writing the given letter to answer the questions and identify the element.
28. Teach students to balance equations and provide simple tips for easy understanding and balancing.

Periodic Properties & Variations of Properties

1. Memorize the first 20 elements in proper order , their positions in the periodic table, valence electrons, valency and metal & non-metallic nature.
2. Factors affecting, variation across the period and group of- atomic size, ionization potential, electron affinity, electronegativity, metallic nature, non-metallic nature.
3. From the concept of valence electrons- writing the formula and predicting the type of bonds.

1. Emphasize that ionization potential increases across a period due to greater nuclear charge, leading to stronger attraction for outer electrons.
2. Highlight that Neon, at the extreme end of the second period, exhibits the highest ionization potential.
3. Conduct regular practice tests covering all periodic trends, including exceptions, and explain these
   trends thoroughly, focusing on noble gases.
4. Explain the variations in properties across periods and groups with numerous examples, relating these changes to atomic structure and nuclear charge.
5. Stress the reasons behind maximum ionization potential in inert gases and teach students to connect periodic properties with atomic structure.
6. Provide students with in-depth information on periodic properties and their variations across periods and down the groups.
7. Use multiple examples and emphasize exceptional cases and clarify that inert gases have zero electron affinity and have no tendency to attract electrons.
8. Teach property trends with clear definitions and ensure a thorough understanding of the concepts.
9. Familiarize students with all properties, except exceptions and teach students the periodic table trends, focusing on periodic properties of elements across periods and down groups.
10. Encourage students to memorize elements up to atomic number 20 and provide ample practice with these elements, focusing on their properties and exceptions.
11. Facilitate group discussions and quizzes to reinforce learning of atomic numbers and valencies for identification and provide practice in writing correct answers with accurate symbols.
12. Emphasize the importance of understanding the electronic configuration of elements and their placement in the periodic table according to group and period based on atomic number.
13. Provide ample practice on trends across periods and down groups, focusing on properties such as exceptions, highest, and lowest elements.
14. Emphasize that metals typically have 1, 2, or 3 valence electrons, while non-metals have 4, 5, 6, or 7.
15. Emphasize that inert gases do not form ions or react due to their stable electronic configuration with 2/ 8 valence electrons.
16. Clearly explain the stability of noble gases compared to other elements based on their electronic configurations and chemical activity.
17. Emphasize the periodic trend of properties of elements as they move across a period from left to right, relating to their electronic configuration.
18. Instruct students not to identify the given elements until asked.
19. Facilitate practice of forming formulas using the given letters and conduct tests to familiarize them with these types of questions.
20. Emphasize writing formulas based on the provided information, especially electronic configuration or atomic number.

1. Factors affecting the formation of ionic and covalent bond.
2. Definition of ionic, covalent and coordinate bond, electrovalency , covalency.
3. Understanding the concept of oxidation and reduction from loss and gain of electrons point of view.
4. Electron dot structure for the formation of – NaCl, CaO, MgCl2, H2, Cl2, O2, N2, CH4, CCl4, H2O, NH3, HCl, H3O+, NH4+.

1. Clarify oxidation-reduction concepts and the roles of oxidizing and reducing agents using equations.
2. Explain that there is electron (loss/gain) in reactions and distinguish oxidation and reduction with examples.
3. Provide relevant examples and repetitive practice to differentiate between lone pairs and shared pairs of electrons.
4. Emphasize lone pairs and coordinate covalent bonds, using diagrams of hydronium and ammonium ions. Draw structures of compound to explain the types of electron pairs.
5. Provide ample practice of drawing electron-dot structures, bonding, and orbital diagrams to discern their differences effectively.
6. Emphasize drawing different elements with distinct notations as dots and crosses, ensuring bonds are not drawn between them.
7. Guide students to differentiate annotations on different elements and provide more practice in drawing these types of electron dot structures.
8. Stress that the bond between metal and non-metal is ionic/electrovalent, leading to electrolytic dissociation.
9. Clarify the distinction between electrolytic dissociation and ionization, focusing on the formation and separation of ions and the compounds involved in these reactions.
10. Explain that when two non-metals combine, they form molecular or covalent bonds, which ionize when put in solution.
11. Emphasize the differences between the properties of electrovalent and covalent compounds, along with the reasons associated with them.
12. Explain the concept and the meaning of electrostatic force and van der Waals forces with their nature and where they exist.
13. Emphasize that when a bond forms between dissimilar atoms with a small electronegativity difference, it results in non-polar covalent compounds.
14. Clearly differentiate between polar and nonpolar covalent compounds based on electron distribution and charge separation using various examples.

1. Concept of acid and base as a producer of H3O+ and OH- ions
2. Concept of pH
3. Colour of litmus, methyl orange, phenolphthalein, and universal indicators in different medium- acidic, alkaline and neutral.
4. Definition with example of – Salt, normal, acid and basic salts
5. Method of preparation and balanced chemical reaction of the formation of the following salts- FeCl3, FeSO4, PbCl2, CaCO3, CuSO4, Na2SO4, PbSO4

1. Explain the concepts of acidic, basic, amphoteric, and neutral oxides with equations, and highlight the differences between amphoteric and other metallic oxides/hydroxides.
2. Teach the basic concept of covalent and ionic compounds and explain water as covalent and calcium oxide as ionic.
3. Explain halogens and alkali metals with their names and symbols and give examples of ionic and covalent compounds along with examples of weak and strong acids.
4. Ensure enough practice with the six methods of salt preparation, including examples and correct equations, and emphasize identifying different salts.
5. Acquaint students with pH scale that represents the concentration of (H3O+) ion in solution.
6. Explain about the particles present in the compounds as whether it is molecules/ions or both molecules and ions with respect to their bondings.
7. Guide students by demonstrating in practical classes to prepare normal salt through complete replacement of the hydronium ion by a metal ion or a base.
8. Acquaint students to the various properties of salts using relevant examples.
9. Ensure students understand amphoteric oxides and their properties.
10. Emphasize the fact that salts of active metals can be prepared by displacement reactions, where dilute acids react with active metals to form salts.
11. Demonstrate these reactions to help students retain the facts and explain the preparation of salts.
12. Familiarize students with the general solubility of salts and emphasize, titration is a common method used to conduct neutralization reactions with suitable bases.
13. Provide extensive practice in writing equations for the preparation of salts through various methods. Illustrate preparing insoluble salts through precipitation methods, emphasizing the solubility of salts and reasons for each method.
14. Teach students to prepare calcium carbonate and other compounds through precipitation reactions, with relevant observations and practice exercises.
15. Focus on the basicity of an acid, specifically the number of hydronium ions produced by one molecule in aqueous solution.
16. Teach students to identify monobasic, dibasic, and tribasic acids based on the number of replaceable hydrogen atoms.
17. Illustrate the concept with examples and explain how to arrange acids in increasing or decreasing order based on their basicity.

1. Colour of the ppt formed, solubility when excess is added , balanced chemical reaction when NaOH and NH4OH are added to – Ca2+, Pb2+, Zn2+, Fe2+, Fe3+, Cu2+ ions
2. Amphoteric nature of Al, Zn, Pb

1. Emphasize the formation of insoluble reddish-brown precipitate, specific to ferric ions, when treated with sodium hydroxide or ammonium hydroxide, whether added in small amounts or in excess.
2. Familiarize students with practical demonstrations to illustrate the formation of this precipitate when alkali is added to ferric salts.
3. Encourage hands-on laboratory experience to enhance observation skills.

1. Numerical related to Gay Lussac’a Law of gaseous volume and Avogadro’s number.
2. Numerical related to empirical and molecular formula.

1. Insist on learning the definitions and familiarize students with all terms in the syllabus, especially RMM, RAM, mole, Avogadro’s law, Gay-Lussac’s law, gram atom, vapor density, etc.
2. Emphasize the concept that the simplest ratio of atoms in a compound is its empirical formula.
3. Guide students to do step-by-step numerical problem-solving and provide ample practice.
4. Explain the equivalence between moles, molar mass, and molar volume.
5. Encourage thorough solutions with correct units and provide additional examples for practice on equation-based problems for calculating relative molecular mass.
6. Guide students on balancing equations and selecting the correct components to calculate mole numbers in compound-based questions.
7. Explain how to use the standard volume of 22.4 liters (or 22,400 cc) in calculations based on the given questions.
8. Emphasize that the molar volume of a gas is the volume occupied by one gram molecular mass or one mole of gas at S.T.P.
9. Stress that molar volume applies only to gases to avoid confusion with substances or compounds.
10. Train students with correct definitions, particularly in mole concept and stoichiometry, to ensure a clear understanding of each concept.
11. Acquaint students with the empirical formula which is the simplest formula that shows the simplest whole number ratio of atoms of different elements in a compound and emphasise on the same.
12. Ensure adequate practice of various numericals and regular stepwise working must be insisted upon.
13. Provide ample practice on the mole concept and stoichiometry, using diverse data, and teach students to complete problems correctly as given in the question paper.
14. Emphasize that Guy Lussac’s Law applies only to gases, not liquids or solids.

Electrolysis

1. Definition of cathode, anode, electrolyte, strong electrolyte, weak electrolyte, non-electrolyte
2. Factors affecting discharge of ions
3. Electrodes taken, electrolyte taken, cathode and anode reaction and observations for-
   a) Electrolysis of acidified water
   b) Molten lead bromide
   c) Copper sulphate with Pt electrodes
   d) Copper sulphate with Cu electrodes
4. Conditions for electroplating
5. Electroplating by Ag and Ni
6. Electro refining of Cu

1. Explain the concept of electroplating clearly, detailing where the article to be plated should be placed and how ions are deposited.
2. Elucidate the roles of the anode and cathode with equations, illustrating the movement of ions and teach the concepts of reducing and oxidizing electrodes clearly.
3. Clearly explain the element valencies and ions present in electrolytes and emphasize the concept of ion migration to specific electrodes.
4. Lay emphasis on the use of DC for smooth and uniform electroplating and the use of low current for a long period.
5. Explain all conditions necessary for a smooth and firm metal deposit during electroplating, including the consequences of using low and high current and ensure students use the correct key words in their explanations.
6. Discuss the differences between simple electrolysis, electroplating, and electrorefining, and provide practice in writing the reactions at the cathode and anode for clarity also emphasize the products formed at each electrode, ensuring students understand that these are neutral atoms or ions.
7. Explain the products and changes at the anode and cathode, detailing observations with both inert and active electrodes.
8. Conduct quizzes and provide practice on processes like roasting, calcination in metallurgy, and using different electrodes in electrolysis.
9. Emphasize observations at each electrode and clarify oxidizing and reducing agents.
10. Ensure students understand the terms involved in electrolysis and stress on their functions.
11. Clarify when and where electrolytic dissociation and ionization occur, particularly in solution or molten states, and explain the associated equations.
12. Provide ample examples and ensure practice of reactions at the cathode and anode under different conditions.

1. Definition of ore, minerals, roasting, calcination
2. Name and formula of the ores of Fe, Al and Zn
3. Name the metals which are concentrated by different methods
4. Reducing agents- C, CO and H2
5. Each and every equations of Baeyer’s and Hall Heroult’s process with temperature. Electrolyte taken, electrolytic reactions, cathode and anode reactions.
6. Alloy- stainless steel, duralumin, magnalium, brass, bronze, fuse metal

1. Clearly explain the differences in alloy compositions and their uses, emphasizing the primary metal in a particular alloy.
2. Provide revision of the compositions of alloys and their primary metals.
3. Emphasize the steps involved in metal extraction from ores.
4. Explain the extraction of aluminium in detail to ensure students can answer correctly.
5. Provide practice of writing the formula and components of the electrolytic mixture used in aluminium extraction, including their ratios and purposes.
6. Emphasize learning the names of important ores and clarify terms related to metallurgy and ensure students understand the processes.
7. Conduct quizzes and provide practice on processes like roasting, calcination in metallurgy, and using different electrodes in electrolysis.
8. Conduct regular quizzes and objective tests to reinforce memory of alloy components and properties.
9. Teach alloys and their components, ensuring students understand the composition and main metal involved in each alloy.
10. Clearly explain metals and other components used in stainless steel, emphasizing that carbon is the only nonmetal used.
11. Emphasize learning the names of ores used in extracting important metals.
12. Teach the concept on the ores used in metal extraction, including their formulas, common names, and chemical names.

Hydrogen Chloride

1. Lab preparation- equation, conditions, drying, collection
2. Fountain experiment
3. Funnel arrangements
4. Reaction of HCl with- ammonia, Sulphide, sulphite, carbonate, MnO2, AgNO3, Pb(NO3)2

1. Create a comparative chart of HCl and NH3 to clarify their collection methods and properties and provide more revision on these topics.
2. Explain when to use upward or downward displacement of air or water during gas collection along with reasoning by using ample examples.
3. Emphasize that silver nitrate is used to detect chloride ions by forming a white precipitate of silver chloride.
4. Emphasize on the products formed with different temperature conditions for above and below 200°C.
5. Emphasize to students that ‘HCl’ gas is denser than air, causing it to displace air upward during collection and explain the process of gas collection and the reason for it to ensure understanding.

1. Lab preparation- equation, conditions, drying, collection
2. Fountain experiment
3. Funnel arrangements
4. Preparation of ammonia from Mg3N2 and AlN
5. Haber’s process
6. Reaction of ammonia with- oxygen, chlorine, HCl, CuO, PbO

1. Clearly explain the fundamental differences between the basic nature and reducing property of ammonia.
2. Demonstrate the laboratory preparation of ammonia to help students understand that it is lighter than air and collected by downward displacement of air.
3. Create a comparative chart of HCl and NH3 to clarify their collection methods and properties and provide more revision on these topics.
4. Explain when to use upward or downward displacement of air or water during gas collection along with reasoning by using ample examples.
5. Teach reactions with clear conditions and observations, emphasizing the words ‘excess with ammonia’ and ‘chlorine’ as separate reactions with equations and products formed.
6. Teach the preparation of ammonia with metal nitrides. making it an alternative method of laboratory preparation.

1. Lab preparation- equation, conditions, drying, collection
2. Why nitric acid produced in lab is yellow- how to make it colourless
3. Ostwald’s process
4. Reaction of nitric acid with- C, S, Cu

1. Demonstrate the brown ring test using freshly prepared ferrous sulphate solution to detect the presence of nitrate or nitric acid.
2. Demonstrate how concentrated Nitric acid oxidizes nascent oxygen to water, releasing Nitrogen dioxide and forming Copper Nitrate.
3. Explain the differences between dilute and concentrated reactions of copper with nitric acid, including products and observations.
4. Emphasize on the products formed with different temperature conditions for above and below 200°C.

1. Contact Process
2. Reaction of sulphuric acid with- C, S, NaCl, NaNO3, Glucose, sucrose, blue vitriol, BaCl2

1. Provide practice of identifying the properties of concentrated sulphuric acid as oxidizing agents with equations.
2. Teach all properties of sulphuric acid with examples and discuss by initiating group discussions in class.
3. Emphasize every step of the industrial process (Contact Process) for preparing sulphuric acid in detail.
4. Demonstrate the ‘BaCl2’ test in the lab for sulphate ions, resulting in the formation of white precipitate (BaSO4).
5. Clarify distinctions between acids, emphasizing dilution and concentration differences along with equations and observations.
6. Familiarize students with various properties of Sulphuric acid and focus on five different properties of sulphuric acid, each with an equation to illustrate the concept.

1. Catenation, Isomerism, Chain isomerism, position isomerism, Homologous series
2. Nomenclature
3. Preparation of methane from sodium acetate and methyl iodide
4. Preparation of ethane from sodium propanoate and bromoethane
5. Reaction of methane with chlorine and oxygen
6. Preparation of ethene from ethanol and ethyl chloride
7. Reaction of ethene with hydrogen, chlorine, bromine and oxygen
8. Preparation of ethyne from calcium carbide, 1,2-dibromoethane
9. Reaction of ethyne with hydrogen, chlorine, bromine and oxygen
10. Preparation of ethanol from ethyl chloride
11. Reaction of ethanol with acetic acid
12. Glacial acetic acid

1. Teach the difference between unsaturated and saturated hydrocarbons and highlight their reactivity and types of reactions they undergo.
2. Facilitate revision and practice of these reactions using structural diagrams.
3. Explain organic compound reactions and their conditions, ensuring adequate revision of each method and practice of writing the equations with examples.
4. Stress the difference between dehydrohalogenation (removal of halogen and water) and dehydration (removal of only water).
5. Familiarize students with terms and their derivatives, such as alkyl, alkane, alkene, and alkyne and clearly explain these concepts with various examples and discuss the bonding of hydrogen with carbon.
6. Acquaint students with naming compounds according to the IUPAC system.
7. Stress the importance of IUPAC nomenclature and structural formulas of organic compounds.
8. Familiarize students with the basic rules, such as selecting the longest chain and numbering carbons, and teach concepts like ‘di’ and ‘tri’ before respective structures.
9. Emphasize regular practice in drawing structures with various compounds.
10. Demonstrate carbon as tetravalent and oxygen as bivalent and emphasize on the functional groups and their proper positioning according to IUPAC nomenclature.
11. Stress the correct placement of functional groups and provide students with numerous structural examples.
12. Emphasize the importance of counting carbon bonds and ensuring the correct number of hydrogens for each carbon to satisfy tetravalency is essential.
13. Provide ample practice for completing and balancing equations of alkanes, alkenes, and alkynes with an emphasis on balancing chemical equations with necessary conditions, especially in organic chemistry.
14. Stress the difference between products formed with aqueous KOH (substitution reaction) and alcoholic KOH (elimination reaction).
15. Explain organic compound preparation with balanced equations and conditions and provide more practice and tests for better understanding.
16. Clarify various functional groups using relevant examples and emphasize terms in organic chemistry.
17. Ensure students learn to write balanced equations and grasp the properties of all organic compounds.
18. Familiarize students with organic compound properties to match descriptions with correct options.
19. Explain properties of key organic compounds like ethanoic acid, also known as glacial acetic acid upon cooling, and discuss its uses.
20. Provide ample practice through short quizzes, board work, and classroom activities to master drawing electron structures, including single, double, and triple bonds.
21. Stress on the products formed on complete combustion of organic compounds as carbon dioxide and water.
22. Ensure correctly placing functional groups and provide students with ample structural examples for better conceptual clarity.
23. Train students to draw structural formulas, ensuring all carbon atoms satisfy their valencies and avoid condensed formulas.
24. Ensure adequate practice through quizzes and structure-writing exercises.
25. Elucidate the diverse uses of organic compounds to get a clear understanding.
26. Familiarize students with the common names and functional groups of organic compounds, with emphasis on writing correct formulas for saturated and unsaturated hydrocarbons and understanding functional groups and IUPAC nomenclature.
27. Emphasize the general formula for alkane, alkene, and alkyne.
28. Clearly explain the differences between saturated and unsaturated hydrocarbons through structures.
29. Ensure students grasp the distinctions between saturated and unsaturated organic compounds by emphasizing bond types and electron availability.
30. Explain catenation and the elements that perform it, including reasons.