.jpeg)
Guess Paper Chemistry Class 10th 2025- All Punjab Boards
This Chemistry guess paper 2025 Class 10th covers key topics from your syllabus, ensuring you focus on what matters the most. Let's dive into the questions and answers!
Important Short Questions of Chemistry Class 10th
1. What is pH, and how can it be measured?
pH is a measure of how acidic or basic a solution is. It can be measured using:
- pH paper
- Universal indicator
- pH meter
2. What is the greenhouse effect?
The greenhouse effect occurs when gases like CO₂, CH₄ (methane), and water vapor trap heat in the Earth’s atmosphere, leading to global warming.
3. What is acid rain? Write its effects.
Acid rain is formed when sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) react with water in the atmosphere. Effects:
- Damages buildings and monuments
- Harms plants and aquatic life
- Reduces soil fertility
4. What are the sources and uses of proteins?
Sources: Meat, eggs, fish, beans, nuts
Uses: Body growth, muscle repair, enzyme production
5. Differentiate between ethane, ethene, and ethyne.
There is single bond between two carbon atoms in ethane while ethene has two bonds and ethyne has triple bond between carbon atoms
6. How can we conserve water?
- Fix leaks and reduce wastage
- Use water-efficient appliances
- Harvest rainwater
7. What are oxidizing agents?
Substances that gain electrons and help in oxidation. Examples:
- Oxygen (O₂)
- Chlorine (Cl₂)
- Potassium permanganate (KMnO₄)
8. What is the fractional distillation of petroleum?
It is the process of separating crude oil into useful components based on their boiling points. Steps:
- Heating crude oil
- Vapors rise in the distillation column
- Separation into different fractions like petrol, diesel, and kerosene
9. What is the structural formula of isobutane?
Isobutane (C₄H₁₀) has a branched structure:
CH3
|
CH3—C—CH3
|
CH3
10. How can alkanes be prepared from alkenes?
By hydrogenation reaction, where hydrogen is added to an alkene in the presence of a catalyst like Pt, Pd, or Ni.
Example:
C₂H₄ + H₂ → C₂H₆
11. What is global warming, and what are its effects?
Global warming is the increase in Earth’s temperature due to excessive greenhouse gases.
Effects:
- Rising sea levels
- Extreme weather conditions
- Melting glaciers
12. What is the role of limestone in ore concentration?
Limestone removes impurities in the extraction of iron from its ore.
Reaction:
CaCO₃ → CaO + CO₂
13. How can alcohol be prepared?
- Fermentation – Sugar is converted into ethanol by yeast.
- Hydration of alkenes – Ethene reacts with water in the presence of a catalyst.
14. Define lipids and their building blocks.
Lipids are organic molecules that store energy. Their building blocks are fatty acids and glycerol.
15. What is the use of reducing agents in metallurgy?
Reducing agents remove oxygen from metal ores to extract pure metals.
Example: Carbon is used to extract iron from iron ore.
16. Define halon with an example.
Halon is a halogen-containing compound used in fire extinguishers.
Example: Ethene reacts with iodine to form ethyl iodide (C₂H₅I).
17. How does water affect soap’s cleansing action?
Hard water contains Ca²⁺ and Mg²⁺ ions, which form insoluble scum with soap, reducing its cleansing power.
18. What are vitamins, and how are they classified?
Vitamins are essential nutrients needed for body functions.
Types:
- Fat-soluble vitamins (A, D, E, K)
- Water-soluble vitamins (B-complex, C)
19. What is the Solvay process?
A method to prepare sodium carbonate (Na₂CO₃).
Reaction:
NaCl + NH₃ + CO₂ + H₂O → NaHCO₃ + NH₄Cl
20. What are waterborne diseases?
Diseases caused by contaminated water, such as:
- Cholera
- Typhoid
- Dysentery
This Class 10th Chemistry Guess Paper 2025 covers the most expected questions for your Punjab board exams like Faisalabad Board, Lahore Board, Rawalpindi Board, Sargodha Board etc., p. Focus on these concepts, practice regularly, and you’ll be well-prepared!
Do you have any questions or need further explanation? Let us know in the comments below!
📌 Bonus Tips for Chemistry Exam Success:
✅ Revise key formulas and reactions
✅ Practice numerical problems
✅ Solve past papers
✅ Stay consistent with your studies
Here are the remaining important questions with short and easy answers:
21. Explain the free radical halogenation of alkanes.
In this reaction, halogens (Cl₂ or Br₂) replace hydrogen in an alkane using free radicals. It occurs in three steps:
- Initiation – Halogen molecule breaks into free radicals.
- Propagation – Radicals react with alkanes to form new radicals.
- Termination – Radicals combine, stopping the reaction.
22. Show how iron and marble can be destroyed by acid rain.
Acid rain reacts with iron and marble, causing damage.
Iron:
Fe + H₂SO₄ → FeSO₄ + H₂
Marble (CaCO₃):
CaCO₃ + H₂SO₄ → CaSO₄ + CO₂ + H₂O
23. What are the macroscopic characteristics of a chemical reaction?
- Color change (e.g., rust formation)
- Gas production (e.g., bubbles in acid-base reactions)
- Temperature change (heat absorption or release)
- Precipitate formation (solid formation in liquid reaction)
24. What is the functional group, catenation, and isomerism?
- Functional group – A group of atoms that define the chemical properties of a compound (e.g., –OH in alcohols).
- Catenation – The ability of carbon to form long chains.
- Isomerism – Compounds with the same molecular formula but different structures.
25. How does NH₃ react with BF₃ to form a coordinate covalent bond?
Ammonia (NH₃) donates a lone pair to boron trifluoride (BF₃), forming a coordinate covalent bond.
Reaction:
NH₃ + BF₃ → NH₃→BF₃
26. What is meant by dynamic equilibrium in chemistry?
It occurs when the rate of the forward reaction equals the rate of the reverse reaction, and the concentrations of reactants and products remain constant.
27. Define acid rain and its effects.
Acid rain is rainwater with acidic pH due to pollutants like SO₂ and NOₓ.
Effects:
- Destroys crops and forests
- Corrodes buildings
- Harms aquatic life
28. What is the difference between n-propyl and isopropyl groups?
29. Define Kc and its units.
Kc (Equilibrium constant) represents the ratio of product concentrations to reactant concentrations at equilibrium.
Formula:
Kc = [Products] / [Reactants]
Units depend on the reaction type.
30. Explain oxidation of methane and acetylene.
Methane oxidation: CH₄ + 2O₂ → CO₂ + 2H₂O
Acetylene oxidation: 2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
31. What are lipids? Discuss fatty acids as their building blocks.
Lipids are fats and oils that store energy. They are made of fatty acids and glycerol.
32. Define and explain alloys.
An alloy is a mixture of metals or a metal and a non-metal to improve properties.
Examples:
- Brass (Cu + Zn)
- Steel (Fe + C)
33. Write two methods to prepare alcohols.
- Fermentation – Yeast converts sugar to alcohol.
- Hydration of alkenes – Alkene reacts with water to form alcohol.
34. How does the dehalogenation of tetrahalides occur?
In dehalogenation, a halogen atom is removed from tetrahalides using a reducing agent like Zn.
Example:
CBr₄ + Zn → C + 2ZnBr₂
35. What is the use of halon compounds?
Halon compounds are used in fire extinguishers because they interrupt combustion without harming electronic devices.
36. How do we enhance permanent hardness of water?
Permanent hardness is caused by Ca²⁺ and Mg²⁺ salts. It can be enhanced by adding more salts like calcium chloride (CaCl₂).
37. What are sources and deficiency symptoms of Vitamin A, C, and D?
38. What is meant by cleansing action of soap?
Soap removes dirt and grease using micelles. These trap oil in water, allowing it to be washed away.
39. How do alkanes differ from alkenes and alkynes?
40. Write methods of salt preparation and give an example.
- Neutralization – Acid + Base → Salt + Water
Example: HCl + NaOH → NaCl + H₂O - Reaction of metals with acids – Zn + H₂SO₄ → ZnSO₄ + H₂
- Precipitation method – Mixing solutions to form an insoluble salt.
41. What are the effects of carbon dioxide (CO₂) on human health?
- Causes breathing difficulties
- Leads to dizziness and headaches
- Contributes to global warming
42. What are two sources of organic compounds?
- Natural sources – Plants, animals
- Synthetic sources – Plastic, medicines
43. Write a general formula for aldehydes and ketones.
- Aldehyde: R–CHO
- Ketone: R–CO–R'
44. Define Brønsted, Arrhenius, and Lewis acids and bases.
- Brønsted Acid – Proton donor (HCl)
- Brønsted Base – Proton acceptor (NH₃)
- Arrhenius Acid – Produces H⁺ ions in water
- Arrhenius Base – Produces OH⁻ ions in water
- Lewis Acid – Electron pair acceptor (BF₃)
- Lewis Base – Electron pair donor (NH₃)
45. What is meant by equilibrium in a chemical reaction?
Equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction and concentrations remain constant.
Conclusion
These are the most important questions for Class 10th Chemistry Guess Paper 2025. Revising these will help you prepare effectively for your exams.
Bonus Tip: Try solving past papers of chemistry class 10 and practice numerical problems to strengthen your concepts.
Good luck with your Chemistry exam!
See Guess papers for Tarjuma Tul Quran Class 9th
