CBSE Class 12 · Chemistry 043
CBSE Class 12 Chemistry, subject code 043, runs through ten units of physical, inorganic and organic chemistry and ends in a three-hour, 70-mark board paper plus a 30-mark practical. Edunest matches a student in Qatar with one chemistry tutor for live online lessons that start from the student's own lost marks in numericals, reasoning and mechanisms.
Class 12 chemistry marks tend to slip in three places: logarithms without a calculator, multi-step organic conversions, and the short 'give reasons' answers of inorganic chemistry. Lessons target all three.
What we cover
The board lists ten units, each with a mark value. Tutors follow that list and the two NCERT textbooks, giving time where the marks sit and where a student keeps slipping.
Concentration terms, Raoult's law, ideal and non-ideal solutions, and colligative properties for finding molar mass. Students mix up molarity with molality, or forget the van 't Hoff factor when a solute dissociates.
Raoult's law · Colligative properties · Abnormal molar mass
Galvanic and electrolytic cells, the Nernst equation, conductance, electrolysis, batteries, fuel cells and corrosion. The heaviest unit; errors come from cell notation, the sign of the cell potential and hand-worked logarithms.
Nernst equation · Molar conductivity · Electrolysis
Rate laws, integrated rate equations, half-life, the effect of temperature on rate, and collision theory. Learners confuse the order of a reaction with its molecularity and misread concentration-time graphs.
Integrated rate equations · Half-life · Temperature dependence
Electronic configurations, oxidation states, colour, magnetism and catalytic activity of transition metals, their key compounds, and the lanthanoids and actinoids. Marks go on the exceptions and on explaining a trend in one clear sentence.
Lanthanoid contraction · Variable oxidation states · Dichromate and permanganate
Werner's theory, IUPAC names, isomerism, bonding in complexes and metal carbonyls. The usual slips are ligands named in the wrong order and a geometry guessed without first counting the d-electrons.
IUPAC naming · Geometrical and optical isomers · Crystal field splitting
Preparation and reactions of halogen and oxygen compounds, SN1 and SN2 substitution, and why phenol is more acidic than an alcohol. Students must predict products from the mechanism and defend an order of reactivity.
SN1 and SN2 · Acidity of phenols · Williamson synthesis
Nucleophilic addition to the carbonyl group, named reactions such as aldol condensation and the Cannizzaro reaction, tests that tell aldehydes from ketones, and carboxylic acid strength. Multi-step conversions are where marks disappear.
Nucleophilic addition · Aldol and Cannizzaro · Tollens' and Fehling's tests
Classification, preparation and basic strength of amines, the Hinsberg test, and diazonium salts as a route to aromatic compounds. Ranking amines by basic strength in water trips many students.
Basic strength · Hinsberg test · Diazonium coupling
Carbohydrates, proteins, enzymes, vitamins, nucleic acids and hormones. The facts are learnable; harder questions ask students to reason from laboratory evidence, such as a Benedict's test on an unknown sugar.
Glucose and its structure · Levels of protein structure · DNA and RNA
Surface chemistry, isolation of elements, polymers and chemistry in everyday life remain in the syllabus and are assessed at school only, outside the board paper.
How lessons run
Every lesson runs live on a shared whiteboard inside a video call, timed on Doha's clock (UTC+3 year-round) to fit after-school hours from Sunday through Thursday.
The first lesson goes through a recent school test or pre-board paper. The tutor sorts each lost mark into physical numericals, inorganic reasoning or organic mechanisms, and shows the student the pattern.
Ten units compete for limited weeks. The plan gives heavy units such as Electrochemistry and carbonyl chemistry more time, follows the school's test dates, and books lessons on weekday evenings or at the Friday-Saturday weekend.
On the whiteboard the tutor draws each mechanism arrow by arrow and works every numerical without a calculator, which the board paper bans. The student then repeats the step alone while the tutor watches.
Titrations and salt analysis take place at school, in the laboratory. In online lessons the tutor drills molarity calculations, the sequence of anion and cation tests, likely viva questions and the investigatory project write-up.
Each week closes with questions in the board's format, from one-mark MCQs to case-based and five-mark answers. The family gets a short progress note, and a parent can watch lessons live whenever they wish.
In the holy month, the chemistry timetable moves to match the official Ramadan hours announced that year.
The exam
Out of 100 marks for chemistry, CBSE sets 70 in its theory paper and the school examines 30 in the practical. Figures below come from the board's 2026-27 syllabus and sample paper.
Exam board
Central Board of Secondary Education (CBSE) · 043
Sets the syllabus, the theory paper and the practical scheme, with one annual Class 12 examination and a supplementary sitting in July.
| Paper | Duration | Marks | Weighting | Calculator |
|---|---|---|---|---|
| Theory paper | 3 hours | 70 | 70% of the subject | Not allowed; no log tables |
Sections A to E, 33 questions: 1-mark MCQs (16), then 2-mark (5), 3-mark (7), case-based 4-mark (2) and 5-mark (3) answers. How a tutor helps The tutor trains timing per section, logarithms by hand and the 'give reasons' style, using the board's sample paper and marking scheme to show where step marks are earned. | ||||
| Practical examination | 30 | 30% of the subject | ||
Volumetric analysis 8, salt analysis 8, content-based experiment 6, project 4, class record and viva 4. How a tutor helps Lessons rehearse permanganate titration calculations against oxalic acid and Mohr's salt, the logic of salt analysis, viva answers and a clear project report, so the student reaches the bench prepared. | ||||
Sections A to E, 33 questions: 1-mark MCQs (16), then 2-mark (5), 3-mark (7), case-based 4-mark (2) and 5-mark (3) answers.
How a tutor helps
The tutor trains timing per section, logarithms by hand and the 'give reasons' style, using the board's sample paper and marking scheme to show where step marks are earned.
Volumetric analysis 8, salt analysis 8, content-based experiment 6, project 4, class record and viva 4.
How a tutor helps
Lessons rehearse permanganate titration calculations against oxalic acid and Mohr's salt, the logic of salt analysis, viva answers and a clear project report, so the student reaches the bench prepared.
Class 12 practicals come first, at school, in front of an external examiner appointed by the board and an internal examiner. The theory paper follows in the board season, with a supplementary sitting in July.
Each subject appears on the certificate with its own score; the board adds no overall percentage. Grades are positional: the top eighth of those who pass receive A1, the next eighth A2, and so on to D2, while E marks an essential repeat.
What we look for in a tutor
Every chemistry tutor we put forward is held to all six.
Degree-level command of physical, inorganic and organic chemistry, so one lesson can move from the Nernst equation to an aldol mechanism.
Works from the current CBSE syllabus and both NCERT Class 12 chemistry textbooks, and knows which topics are assessed only at school.
Has taught students through CBSE-style papers and marking schemes, including case-based questions, internal choices and the step marks inside long answers.
Draws structures, curly arrows and cell diagrams on the shared whiteboard, then asks the student to explain them back before moving on.
Keeps to safeguarding rules for anyone under 18: professional conduct, lessons kept to the family's chosen video platform, and parents free to observe any lesson.
Writes brief progress notes that name the units covered, the errors still recurring and the focus for the coming week.
Common difficulties
Six of them, phrased the way students usually describe them.
Why it happens
The board paper allows no calculators or log tables, and Nernst and kinetics questions both need logarithms.
How a tutor helps
The tutor teaches a small set of log values and approximation habits, then sets hand-worked problems each week until the arithmetic stops costing marks.
Why it happens
Named reactions and reagents pile up across four organic units, and learning them one by one hides the logic linking them.
How a tutor helps
Lessons build one reaction map per functional group, explain each step through its mechanism, and finish with two-step and three-step conversion drills.
Why it happens
IUPAC rules for ligands, oxidation state and charge are strict, and a single slip loses the whole mark.
How a tutor helps
Short naming and isomer-counting rounds open each lesson, with the tutor correcting one rule at a time until the student names unfamiliar complexes unaided.
Why it happens
These questions ask why a trend happens, such as lanthanoid contraction or variable oxidation states, in one tight explanation.
How a tutor helps
The student practises two-line reasons against marking-scheme wording, and the tutor trims vague answers into the cause-and-effect form that earns the mark.
Why it happens
The practical is worth 30 marks, and the order of tests and the chemistry behind each observation must be clear.
How a tutor helps
Lessons walk through anion and cation flow charts, confirmatory tests and common viva questions, so the student can explain every step at the bench.
Why it happens
Section D gives a passage, table or graph, then tests reasoning from that data.
How a tutor helps
The tutor practises reading the data first, marking what each part asks, and answering in the order that saves the most minutes.
Questions learners and parents ask
Share the school, the units that worry your child most and the evenings that suit; someone at Edunest reads it and replies personally.