Key takeaways
- Seven units: water, water treatment, fuels, corrosion, electrochemistry, polymers and practice questions.
- Solved examples on hardness, calorific value and cell EMF.
- Tables on softening methods, boiler troubles, batteries and important polymers.
- Ten practice questions at the end, mixing theory and numericals.
- Original Uncodemy revision notes; check your own university syllabus.
About these handwritten notes
These are original Uncodemy revision notes for Engineering Chemistry, written in a clean handwritten style so they feel like a topper's notebook rather than a textbook. They are short on purpose: each unit gives the key definitions, formulas, a solved example or two and the points that are easy to forget.
The notes follow the common syllabus that most Indian B.Tech universities use for this subject, including universities that follow the AICTE model curriculum. They are not official notes from any university. Unit names, order and depth differ from one university to another, so check your own university syllabus and mark any topic that is missing before you rely on the notes for an exam. Chemistry papers reward neat reactions, labelled diagrams and step-by-step numericals, so the notes give all three for each unit.
What's inside the engineering chemistry notes
The notes have seven units. One line on each:
Unit 1: Water and hardness
Hard and soft water, temporary and permanent hardness, units of hardness, CaCO₃ equivalents with a solved example, and the EDTA method.
Unit 2: Water treatment
Lime-soda, zeolite and ion exchange softening, boiler troubles (scale and sludge, priming and foaming, caustic embrittlement, boiler corrosion) and the steps of drinking water treatment, including break-point chlorination and desalination.
Unit 3: Fuels
Calorific value, HCV and LCV, Dulong's formula with a solved example, proximate and ultimate analysis of coal, refining and cracking of petroleum, knocking, octane and cetane numbers, and gaseous fuels.
Unit 4: Corrosion
Dry and wet corrosion, galvanic and differential aeration corrosion, the reactions for rusting of iron, the Pilling-Bedworth rule and prevention by cathodic protection and coatings.
Unit 5: Electrochemistry
Electrochemical cells, the standard hydrogen electrode, cell EMF, the Nernst equation with a solved example, common batteries and fuel cells, and conductometric and potentiometric titrations.
Unit 6: Polymers
Monomers and degree of polymerisation, addition and condensation polymerisation, thermoplastics vs thermosetting plastics, important polymers, vulcanisation, and conducting and biodegradable polymers.
Unit 7: Most asked questions (practice)
Ten practice questions across the six units.
How to revise engineering chemistry with these notes
- Practise the two standard numericals first. The notes say almost every paper has a hardness numerical and a calorific value numerical. Do several of each until the steps are automatic.
- Learn the conversion factors. In hardness problems, convert each salt to its CaCO₃ equivalent. In lime-soda problems, use 74/100 for lime and 106/100 for soda, then multiply by the volume.
- Write reactions in full. EDTA, zeolite, corrosion of iron and cell reactions carry marks only when written correctly with charges and states.
- Use tables for comparison questions. Softening methods, boiler troubles, batteries and thermoplastics vs thermosetting plastics are easiest to learn as tables, and examiners like a table answer too.
- Do cell EMF step by step. Write the half-reactions, find E°cell = E°cathode - E°anode, then apply the Nernst equation.
- Learn three polymers fully. PVC, nylon 6,6 and Bakelite: monomers, preparation and uses. They are the most commonly asked.
Exam focus: high-weightage topics
The tip at the end of the notes says every paper usually has a hardness numerical and a calorific value numerical, and advises learning corrosion reactions and cell EMF calculation step by step.
Topics worth extra time:
- Hardness: calculate temporary, permanent and total hardness from a salt table.
- EDTA method: principle, reactions and the calculation.
- Softening: zeolite and ion exchange processes, and lime-soda requirement numericals.
- Boiler troubles: especially caustic embrittlement and its prevention.
- Fuels: HCV and LCV by Dulong's formula; knocking with octane and cetane numbers.
- Corrosion: electrochemical theory of corrosion and methods of prevention.
- Electrochemistry: derive the Nernst equation and find the EMF of a cell.
- Polymers: thermoplastics vs thermosetting, and the preparation and uses of PVC, nylon 6,6 and Bakelite.
Typical questions
These topics match the ten practice questions in the PDF. They are practice questions and not a prediction of your exam.
Who these notes are for
- First-year B.Tech students of all branches taking Engineering Chemistry in semester 1 or 2.
- Civil, mechanical and chemical engineering students, who meet water treatment, fuels and corrosion again in later core subjects.
- Students making a quick formula and reaction sheet before the chemistry exam.
For unit-wise practice questions with answer outlines, pair these notes with the Engineering Chemistry important questions PDF.
Common mistakes to avoid
- Forgetting the CaCO₃ equivalent. Hardness is always expressed in terms of CaCO₃. Multiply each salt by 100 divided by its molar mass (or equivalent mass, as your syllabus uses).
- Counting salts that do not cause hardness. Sodium and potassium salts do not add to hardness.
- Mixing up HCV and LCV. LCV = HCV minus the latent heat of the steam formed from hydrogen in the fuel.
- Swapping anode and cathode. Oxidation happens at the anode and reduction at the cathode, in corrosion and in cells.
- Using the wrong sign in the Nernst equation. Write the equation for the full cell reaction before putting in the numbers.
Key reactions and formulas to know by heart
Before the exam, check that you can write these from memory:
- CaCO₃ equivalent = (mass of salt x 100) / molar mass of the salt, for salts with a 2+ ion.
- The lime and soda requirement formulas with the factors 74/100 and 106/100.
- The zeolite exchange reaction and how the zeolite is regenerated with brine.
- Dulong's formula for HCV, and the relation between HCV and LCV.
- The anode and cathode reactions for rusting of iron in neutral, moist conditions.
- E°cell = E°cathode - E°anode and the Nernst equation at 25 °C.
- The monomers of polythene, PVC, Teflon, nylon 6,6 and Bakelite.
If you can write each of these without looking, most of the numericals and short questions in the practice set become straightforward.
A simple 4-day revision plan
- Day 1: Units 1 and 2. Hardness, EDTA, softening and boiler troubles, with two hardness numericals.
- Day 2: Unit 3. Fuels, Dulong's formula and coal analysis, with two calorific value numericals.
- Day 3: Units 4 to 6. Corrosion, electrochemistry and polymers.
- Day 4: Solve the ten practice questions with a timer and revise all reactions once more.
Download Engineering Chemistry Handwritten Notes PDF
Engineering Chemistry Handwritten Notes PDF
The PDF carries the same content as this page in a clean, print-ready layout, so you can read it offline and keep it for revision.
6 pages · 226 KB · PDF · Updated 5 Nov 2026