BCHCT 135 key facts: June 2026
- Course code: BCHCT 135 (printed BCHCT-135)
- Course title: Solutions, Phase Equilibrium, Conductance, Electrochemistry and Functional Group Organic Chemistry-II
- Programme: B.Sc. (General) BSCG; the June 2026 paper is also printed for B.Sc. (Multidisciplinary) BSCM
- Credits: 4 (theory), taken with the 2-credit lab course BCHCL 136
- Blocks and units: 4 blocks, 16 units
- Maximum marks: 50
- Duration: 2 hours
- Questions in the paper: 14 (Q1 to Q7 in Part A, Q8 to Q14 in Part B; answer any 5 from each part)
- Answer sheets: Part A and Part B are written on separate sheets
- Paper language: printed in English and Hindi
- Samples shown on this page: 2 (Q1 and Q9); all 14 in the paid file
BCHCT 135 Solved Question Paper June 2026 answers every question of the official term-end paper for BCHCT 135, the 4-credit core chemistry course in IGNOU's B.Sc. (General) on solutions, phase equilibrium, conductance, electrochemistry and functional group organic chemistry.
1. What the June 2026 Solved Paper Covers
The June 2026 paper carries 50 marks for 2 hours. Part A (Q1 to Q7) is physical chemistry and Part B (Q8 to Q14) is organic chemistry. You attempt any five from each part in separate answer sheets, and every question is worth 5 marks.
This session leans hard on calculation. You meet the vapour pressures of pure A and B from two mixtures, the vapour pressure of liquid A in steam distillation at 363 K, and the Gibbs energy change of a hydrogen-copper cell when half a mole of copper is deposited.
Part B is just as specific: an acid chloride over Pd-BaSO4, aniline with nitrous acid and with chloroform, Sanger's end-group method, Ruff degradation of glucose and a cellulose versus starch comparison.
If you are collecting papers for the whole semester, our BSCG Question Paper page groups the other B.Sc. (General) course codes in one place.
2. Two Answers Solved in Full, Twelve Held Back
Two BCHCT 135 answers are open below in full, Q1 from Part A and Q9 from Part B, while the other 12 questions of the June 2026 paper are listed exactly as printed and answered only in the full file.
Molarity versus molality, and pure vapour pressures by Raoult's law
Question 1 (a): Which of the following concentration terms depends on temperature: (i) molarity or (ii) molality? Give reason in support of your choice. (2)
Question 1 (b): A binary liquid solution (ideal solution) was formed by mixing 1.0 mol of A and 2.0 mol of B at 298 K. The total vapour pressure of the solution was found to be 2.0 × 105 Pa. When 1.0 mol of B was further added to the above solution, the total vapour pressure rose to 2.1 × 105 Pa. Calculate the vapour pressure of components A and B in the pure state. (3)
(a) Molarity depends on temperature, molality does not
Molarity (M) = moles of solute ÷ volume of solution in litres. A liquid solution expands on heating and contracts on cooling, while the moles of solute stay fixed. So the same solution shows a lower molarity at a higher temperature.
Molality (m) = moles of solute ÷ mass of solvent in kilograms. Mass does not change with temperature, so molality stays constant. This is why molality, not molarity, is used for colligative properties such as elevation of boiling point and depression of freezing point, where temperature itself changes.
(b) Vapour pressures of pure A and pure B
Pure A has a vapour pressure of 1.2 × 105 Pa and pure B has 2.4 × 105 Pa.
For an ideal solution, Raoult's law gives the total vapour pressure as p = xAp°A + xBp°B, where x is the mole fraction of each component and p° is the vapour pressure of the pure liquid.
First solution: nA = 1.0 mol and nB = 2.0 mol, total 3.0 mol, so xA = 1/3 and xB = 2/3.
2.0 × 105 = (1/3)p°A + (2/3)p°B, which gives p°A + 2p°B = 6.0 × 105 Pa ...(i)
Second solution: after adding 1.0 mol of B, nB = 3.0 mol, total 4.0 mol, so xA = 1/4 and xB = 3/4.
2.1 × 105 = (1/4)p°A + (3/4)p°B, which gives p°A + 3p°B = 8.4 × 105 Pa ...(ii)
Subtracting (i) from (ii): p°B = 2.4 × 105 Pa. Putting this into (i): p°A = 6.0 × 105 − 4.8 × 105 = 1.2 × 105 Pa.
Check. (1/3)(1.2 × 105) + (2/3)(2.4 × 105) = 2.0 × 105 Pa, and (1/4)(1.2 × 105) + (3/4)(2.4 × 105) = 2.1 × 105 Pa. Both totals match the question.
The result also makes physical sense. B is the more volatile liquid, with the higher pure vapour pressure, so adding more B raises the total vapour pressure of the solution, exactly as the question reports.
Mechanism of Fischer esterification
Question 9: Discuss the mechanism of Fischer esterification. Give the reactions involved. (5)
Fischer esterification is the acid-catalysed, reversible reaction of a carboxylic acid with an alcohol to give an ester and water, and it proceeds by nucleophilic acyl substitution through a tetrahedral intermediate.
General reaction: RCOOH + R′OH ⇌ RCOOR′ + H2O (catalyst: concentrated H2SO4 or dry HCl, heat)
Example: CH3COOH + C2H5OH ⇌ CH3COOC2H5 + H2O (ethanoic acid + ethanol gives ethyl ethanoate)
Why the acid is needed. The carboxyl carbon is only weakly electrophilic and an alcohol is a weak nucleophile. Protonating the carbonyl oxygen makes that carbon far more positive, so the alcohol can attack it.
Mechanism, using ethanoic acid and ethanol
- Protonation of the carbonyl oxygen. CH3-C(=O)-OH + H+ ⇌ CH3-C+(OH)2. The positive charge is shared by resonance between carbon and both oxygens.
- Nucleophilic attack by the alcohol. CH3-C+(OH)2 + C2H5OH ⇌ CH3-C(OH)2-O+H-C2H5. A lone pair on the alcohol oxygen bonds to carbon, forming the tetrahedral intermediate.
- Proton transfer. CH3-C(OH)2-O+H-C2H5 ⇌ CH3-C(OH)(OC2H5)-O+H2. The proton moves to one OH group, turning it into a good leaving group.
- Loss of water. CH3-C(OH)(OC2H5)-O+H2 ⇌ CH3-C(=O+H)-OC2H5 + H2O. The carbonyl double bond reforms as water leaves.
- Deprotonation. CH3-C(=O+H)-OC2H5 ⇌ CH3COOC2H5 + H+. The ester forms and H+ is regenerated, which is why only a catalytic amount of acid is needed.
Isotope evidence. When the alcohol is labelled with oxygen-18, the label ends up in the ester and none appears in the water:
CH3CO-OH + H-18O-C2H5 ⇌ CH3CO-18O-C2H5 + H2O
This shows that the acyl-oxygen bond of the acid breaks, not the alkyl-oxygen bond of the alcohol, which is exactly what the mechanism above predicts.
Shifting the equilibrium. Every step is reversible, and for ethanoic acid with ethanol the equilibrium constant is close to 4, so equimolar amounts give only about two-thirds ester. Yield improves if the alcohol is used in excess or water is removed as it forms (concentrated H2SO4 also acts as a dehydrating agent).
Limits. Tertiary alcohols tend to dehydrate to alkenes under these acidic conditions, and bulky acids or alcohols react slowly because the crowded tetrahedral intermediate is harder to form. The reverse process, acid-catalysed hydrolysis of an ester, follows the same steps in the opposite order.
3. Questions Answered Only in the Full File
Structures drawn in the printed paper are written as formulas below; the wording, numbering and marks are unchanged.
Part A: Physical Chemistry
Question 2 (a): What is the critical solution temperature (CST) of a partially miscible liquid system? Draw a CST curve for the phenol-water system. What is the effect of adding NaCl as an impurity on the CST? (3)
Question 2 (b): A mixture of water and an organic liquid A (immiscible in water) distils at 363 K at an external pressure of 1.00 × 105 Pa. Calculate the vapour pressure of organic liquid A at 363 K, if the vapour pressure of water at 363 K is 8.35 × 104 Pa. (2)
Question 3 (a): Derive the Clapeyron equation. (3)
Question 3 (b): A system contains ice, ethyl alcohol and water. Using the phase rule, calculate the degrees of freedom for it. (2)
Question 4 (a): Draw the phase diagram for a two-component system from the following data. (4)
(i) m.p. A = 600 °C (ii) m.p. B = 400 °C (iii) m.p. AB2 = 700 °C (iv) eutectic: 25 mol % B at 450 °C (v) eutectic: 84 mol % B at 320 °CQuestion 4 (b): What is the unit of the cell constant of a conductivity cell? (1)
Question 5 (a): What are transference numbers? How are these related to ionic mobilities? (3)
Question 5 (b): What is the ionic product of water? What is its value at 25 °C and 1 atm pressure? (2)
Question 6 (a): What is the relationship between the standard emf of a cell and the standard Gibbs energy change of the reaction? (1)
Question 6 (b): Calculate the Gibbs energy change of the reaction occurring in the cell Pt, H2(g) | H+(aq), C = 1 || Cu2+(aq), C = 1 | Cu(s). Given: (i) E° for Cu2+|Cu = 0.34 V (ii) E° for Pt|H2|H+ = 0.00 V (iii) ½ mole of Cu(s) gets deposited on the copper electrode. (4)
Question 7 (a): Write the redox reaction occurring at the quinhydrone electrode. Write the expression for its electrode potential in the form of the Nernst equation. (2)
Question 7 (b): Draw a potentiometric titration curve for the titration of a strong acid against a strong base. Mark the equivalence point and explain how it is determined. (3)
Part B: Organic Chemistry
Question 8: Complete the following reactions. (5)
(i) CH3-CO-Cl → [H2/Pd-BaSO4, quinoline]
(ii) C6H5NH2 → [NaNO2, HCl, 0 °C]
(iii) C6H5NH2 + CHCl3 + 3NaOH →
(iv) C6H5OH + C6H5COCl → [NaOH, pyridine]
(v) CHO-(CHOH)4-CH2OH → [Br2/H2O]Question 10 (i): Arrange the following carboxylic acid derivatives in decreasing order of their reactivity towards nucleophilic acyl substitution, giving reasons: CH3-CO-O-CO-CH3, CH3CONH2, CH3-CO-Cl, CH3-CO-OCH3 (1 + 2)
Question 10 (ii): Which is more basic, methylamine or aniline? Give reasons. (2)
Question 11 (i): The Hofmann elimination of an amine yielded ethene and propene. What could be its possible structure? (2)
Question 11 (ii): Write the products of nitrosation of the following compounds. (3)
(a) C6H5NH2 (b) C6H5N(CH3)3 (c) C6H5CH2-NH-CH3Question 12 (i): How will you identify the N-terminus of a peptide chain using Sanger's method? Give the reactions involved. (3)
Question 12 (ii): Which type of structure is formed by the overall three-dimensional folding of two or more polypeptide chains? Give an example. (2)
Question 13 (i): Explain why sucrose is a non-reducing sugar. (2)
Question 13 (ii): Give the reactions involved in the conversion of glucose to arabinose using Ruff degradation. (3)
Question 14 (i): Give three differences between cellulose and starch. (3)
Question 14 (ii): What is a peptide bond? How is it formed? (1 + 1)
4. Block and Unit Syllabus with June 2026 Question Links
BCHCT 135 is organised into 4 blocks and 16 units: two physical chemistry blocks (solutions and phase equilibrium; conductance and electrochemistry) and two organic blocks (acids, derivatives and amines; peptides, proteins and carbohydrates).
The block titles and unit list below follow the course page on eGyanKosh, IGNOU's official repository. The last column shows which June 2026 questions draw on each unit, so you can see where the marks really sit.
| Block | Unit | Key topics | June 2026 questions |
|---|---|---|---|
| Block 1: Solutions and Phase Equilibrium | Unit 1: Solutions-I | Molarity, molality and mole fraction; Raoult's law for ideal solutions; vapour pressure-composition curves | Q1 (Sample 1) |
| Block 1: Solutions and Phase Equilibrium | Unit 2: Solutions-II | Partially miscible liquids and CST; immiscible liquids and steam distillation; Nernst distribution law | Q2 |
| Block 1: Solutions and Phase Equilibrium | Unit 3: Phase Equilibrium-I | Phase, component and degrees of freedom; phase rule for one-component systems; Clapeyron equation | Q3 |
| Block 1: Solutions and Phase Equilibrium | Unit 4: Phase Equilibrium-II | Two-component solid-liquid systems; simple eutectics; compounds with congruent melting points | Q4(a) |
| Block 2: Conductance and Electrochemistry | Unit 5: Conductance-I | Conductivity and molar conductivity; cell constant; variation with dilution | Q4(b) |
| Block 2: Conductance and Electrochemistry | Unit 6: Conductance-II | Transference numbers and ionic mobility; moving boundary method; ionic product of water | Q5 |
| Block 2: Conductance and Electrochemistry | Unit 7: Electrochemistry-I | Galvanic cell notation; standard electrode potentials; emf and Gibbs energy change | Q6 |
| Block 2: Conductance and Electrochemistry | Unit 8: Electrochemistry-II | Hydrogen and quinhydrone electrodes for pH; Nernst equation for electrodes; potentiometric titrations | Q7 |
| Block 3: Carboxylic Acids, Their Derivatives and Amino Compounds | Unit 9: Carboxylic Acids | Acidity of carboxylic acids; esterification with alcohols; reactions at the carboxyl group | Q9 (Sample 2) |
| Block 3: Carboxylic Acids, Their Derivatives and Amino Compounds | Unit 10: Carboxylic Acid Derivatives | Acid chlorides, anhydrides, esters and amides; nucleophilic acyl substitution; reactivity order | Q8(i), Q8(iv), Q10(i) |
| Block 3: Carboxylic Acids, Their Derivatives and Amino Compounds | Unit 11: Amines | Basicity of aliphatic and aromatic amines; Hofmann elimination; reactions with nitrous acid and chloroform | Q8(iii), Q10(ii), Q11 |
| Block 3: Carboxylic Acids, Their Derivatives and Amino Compounds | Unit 12: Diazonium Salts | Diazotisation of aromatic amines; stability of diazonium salts at 0 to 5 °C; replacement reactions | Q8(ii) |
| Block 4: Peptides, Proteins and Carbohydrates | Unit 13: Amino Acids and Peptides | Peptide bond formation; N-terminal analysis with Sanger's reagent; zwitterions and isoelectric point | Q12(i), Q14(ii) |
| Block 4: Peptides, Proteins and Carbohydrates | Unit 14: Structure of Peptides and Proteins | Primary and secondary structure; tertiary folding; quaternary structure of multi-chain proteins | Q12(ii) |
| Block 4: Peptides, Proteins and Carbohydrates | Unit 15: Carbohydrates-I: Monosaccharides | Open-chain and ring forms of glucose; oxidation with bromine water; Ruff and Kiliani-Fischer methods | Q8(v), Q13(ii) |
| Block 4: Peptides, Proteins and Carbohydrates | Unit 16: Carbohydrates-II: Disaccharides and Polysaccharides | Sucrose and its glycosidic link; starch (amylose, amylopectin); cellulose | Q13(i), Q14(i) |
Block 1 alone supplies Q1, Q2, Q3 and Q4(a), which is 19 of the 35 marks printed in Part A. If your own notes are thin on phase diagrams or partially miscible liquids, work through our BCHCT 135 Study Material before you open the solved file.
5. Paper Pattern: Part A, Part B and Marks
The paper has 14 questions of 5 marks each, split 7 and 7 between Part A and Part B, and you answer 10 of them for a total of 50 marks in 2 hours.
| Part | Questions | Branch | You answer | Marks | Internal split in June 2026 |
|---|---|---|---|---|---|
| Part A | Q1 to Q7 | Physical chemistry (Blocks 1 and 2) | Any 5 of 7 | 25 | Q1 2+3, Q2 3+2, Q3 3+2, Q4 4+1, Q5 3+2, Q6 1+4, Q7 2+3 |
| Part B | Q8 to Q14 | Organic chemistry (Blocks 3 and 4) | Any 5 of 7 | 25 | Q8 five 1-mark reactions, Q9 single 5-mark answer, Q10 1+2+2, Q11 2+3, Q12 3+2, Q13 2+3, Q14 3+1+1 |
| Total | 14 questions | Separate answer sheets for each part | 10 of 14 | 50 | 2 hours, about 12 minutes per answer |
Because the choice sits inside each part, you cannot skip organic chemistry and make up the marks in physical chemistry. Plan for five full answers from each side before exam day.
The paper has kept this 7 plus 7 layout in every sitting we checked. You can compare older sheets in our IGNOU Previous Year Question Paper collection, organised by course code and session.
Numericals such as Q1(b), Q2(b) and Q6(b) reward a clear formula line and correct units more than long prose, so keep theory answers tight and leave time to draw the three diagrams the paper asks for.
6. Topics Repeated in Official Papers, 2023 to 2026
Across the four official BCHCT 135 papers we could check (December 2023, June 2024, December 2024 and June 2026), six topic groups appeared in all four sittings.
Each cell shows the question number in that paper, so you can open the originals and compare the wording. The June 2025 and December 2025 papers are listed on ignou.ac.in, but we could not retrieve those PDFs, so they are not counted here.
| Topic | Unit | Dec 2023 | Jun 2024 | Dec 2024 | Jun 2026 | Sittings (of 4) |
|---|---|---|---|---|---|---|
| Transference numbers and moving boundary method | Unit 6 | Q4 | Q5(a) | Q5(b) | Q5(a) | 4 |
| pH with hydrogen or quinhydrone electrode, emf methods | Unit 8 | Q3(b) | Q7(a) | Q7(a) | Q7(a) | 4 |
| Cell notation, standard emf and Gibbs energy or spontaneity | Unit 7 | Q3(a) | Q6(b) | Q6 | Q6 | 4 |
| Telling primary, secondary and tertiary amines apart | Unit 11 | Q10 | Q10(a) | Q10(a) | Q11(ii) | 4 |
| Sugar chain shortening or lengthening (Ruff, Kiliani-Fischer) | Unit 15 | Q14(a) | Q12(b) | Q14(a) | Q13(ii) | 4 |
| Complete-the-reactions set | Blocks 3 and 4 | Q9 | Q8 | Q8 | Q8 | 4 |
| Critical solution temperature and partially miscible liquids | Unit 2 | — | Q2(b) | Q2(a) | Q2(a) | 3 |
| Phase rule counts (phases, components, degrees of freedom) | Unit 3 | — | Q4(a) | Q4(a) | Q3(b) | 3 |
| Two-component diagrams with a compound | Unit 4 | Q6(a) | — | Q3 | Q4(a) | 3 |
| Conductometric or potentiometric titration curves | Units 6 and 8 | — | Q4(b) | Q4(b) | Q7(b) | 3 |
| Glucose with bromine water | Unit 15 | Q9(vi) | Q8(iv) | — | Q8(v) | 3 |
| Aniline with nitrous acid (diazotisation route) | Unit 12 | Q11(a) | Q8(ii) | — | Q8(ii) | 3 |
| Fischer esterification | Unit 9 | Q9(i) | — | Q13(b) | Q9 (Sample 2) | 3 |
| Reactivity order of acid derivatives | Unit 10 | — | Q11(a) | Q10(b) | Q10(i) | 3 |
| Basicity of amines | Unit 11 | — | Q10(b) | Q11(a) | Q10(ii) | 3 |
| Levels of protein structure | Unit 14 | — | Q14(a) | Q12 | Q12(ii) | 3 |
| Cellulose (units, linkage, comparison with starch) | Unit 16 | Q13(b) | Q12(c) | — | Q14(i) | 3 |
| Raoult's law vapour pressure numerical | Unit 1 | — | — | Q1(b) | Q1(b) (Sample 1) | 2 |
| Steam distillation numerical | Unit 2 | — | Q2(a) | — | Q2(b) | 2 |
| Sanger's N-terminal analysis | Unit 13 | Q13(a) | — | — | Q12(i) | 2 |
| Sucrose as a non-reducing sugar | Unit 16 | Q12(c) | — | — | Q13(i) | 2 |
Treat the count as a guide, not a forecast. Our wider list of IGNOU Solved Guess Paper topics ranks repeats across many codes, but for this course the six four-sitting topics above are the safest first revision targets.
7. How Our Answers Are Written and Checked
Every BCHCT 135 answer in the file follows the same exam logic: state the principle, write the equation, substitute the values with units, then check the result against the data in the question.
In Q1(b) above, both pure vapour pressures are put back into the two mixtures to confirm 2.0 × 105 Pa and 2.1 × 105 Pa. The same closing check runs through the steam distillation and cell Gibbs energy problems in the file.
Questions that ask you to draw, such as the phenol-water CST curve, the A-B phase diagram with AB2 and the potentiometric titration curve, get labelled sketches with axes, regions and the key point marked.
Organic answers write the reagent over each arrow and name every product, because examiners mark the product and the condition separately.
8. Practical File Index with BCHCL 136
BCHCT 135 is studied together with the 2-credit lab course BCHCL 136, and several of its experiments sit directly behind questions in the June 2026 paper.
| Experiment | BCHCL 136 work | BCHCT 135 unit | June 2026 link |
|---|---|---|---|
| Exp 1 | Study the equilibrium of reactions by the distribution method | Unit 2 | — |
| Exp 3 | Mutual solubility temperature against concentration for phenol-water and its CST | Unit 2 | Q2(a) CST curve |
| Exp 4 | Effect of impurities on the CST of the phenol-water system | Unit 2 | Q2(a) effect of NaCl |
| Exp 5 | Dissociation constant of a weak acid using a pH meter | Unit 8 | — |
| Exp 6 | Conductometric titrations of acids and bases | Units 5 and 6 | Q4(b) cell constant unit |
| Exp 7 | Potentiometric titrations of acids and bases | Unit 8 | Q7(b) titration curve |
The six experiments above are the ones we have matched to this paper; check your BCHCL 136 manual for the rest, including the cooling-curve phase diagram that supports Q4(a) and the qualitative analysis of carboxylic acids behind Q8(iv) and Q9.
9. Solved File Index
The solved file answers all 14 questions of the paper: 2 are on this page (Q1 and Q9) and 12 are in the full file only.
| Question | Part | Units | Marks split | Where the answer is |
|---|---|---|---|---|
| Q1 | A | Unit 1 | 2 + 3 | Sample 1 above |
| Q2 | A | Unit 2 | 3 + 2 | Full file |
| Q3 | A | Unit 3 | 3 + 2 | Full file |
| Q4 | A | Units 4 and 5 | 4 + 1 | Full file |
| Q5 | A | Unit 6 | 3 + 2 | Full file |
| Q6 | A | Unit 7 | 1 + 4 | Full file |
| Q7 | A | Unit 8 | 2 + 3 | Full file |
| Q8 | B | Units 10, 11, 12 and 15 | 5 × 1 | Full file |
| Q9 | B | Unit 9 | 5 | Sample 2 above |
| Q10 | B | Units 10 and 11 | 1 + 2 + 2 | Full file |
| Q11 | B | Unit 11 | 2 + 3 | Full file |
| Q12 | B | Units 13 and 14 | 3 + 2 | Full file |
| Q13 | B | Units 15 and 16 | 2 + 3 | Full file |
| Q14 | B | Units 13 and 16 | 3 + 1 + 1 | Full file |
10. Programmes That Include BCHCT 135
BCHCT 135 is a Discipline Specific Core course in the chemistry stream of IGNOU's B.Sc. (General), and the June 2026 paper was printed jointly for B.Sc. (Multidisciplinary) learners under the same code.
In the IGNOU Bachelor of Science (General) (BSCG) scheme, BCHCT 135 carries 4 credits and must be taken together with BCHCL 136, the matching laboratory course. It sits between BCHCT 133 and BCHCT 137 in the chemistry core sequence.
The June 2026 paper header names both BSCG and BSCM, so learners from either programme sat the same paper, printed in English and Hindi.
11. How to Get the Full Solved Question Paper
Send a WhatsApp message to 9899436384 with the code BCHCT 135 and the session June 2026, and our team will share the full solved file with all 14 answers, including the 12 not shown on this page.
- Save 9899436384 and open WhatsApp.
- Type "BCHCT 135 June 2026" so we send this paper and not an older session.
- Our team replies with the price and delivery details for the file.
Students often ask for the file a few days before the term-end exam. Messaging early leaves time to practise the Q4 phase diagram and the Q6 cell calculation by hand.
12. BCHCT 135 FAQs
These answers cover what the BCHCT 135 June 2026 file contains, how to get it and how the paper is marked.
What does the Solved Question Paper June 2026 include?
It includes complete answers to all 14 questions of the official June 2026 BCHCT 135 paper, seven from physical chemistry in Part A and seven from organic chemistry in Part B. Two answers, Q1 and Q9, are shown in full on this page. The remaining 12 answers, including the phase diagram, the cell Gibbs energy problem and Sanger's method, are in the full file.
How do I get the full answers on WhatsApp?
Send a WhatsApp message to 9899436384 with the text BCHCT 135 June 2026. Our team replies with the price and delivery details and then shares the full solved file. It contains answers to all 14 questions in the paper: the 2 shown on this page plus the 12 that appear here only as question text.
Which BCHCT 135 topics repeat most in official papers?
In the four official papers we checked (December 2023, June 2024, December 2024 and June 2026), six topic groups came up every time: transference numbers, pH electrodes, cell emf and Gibbs energy, tests that separate primary, secondary and tertiary amines, Ruff or Kiliani-Fischer sugar conversions, and a complete-the-reactions question. Revise these first, then move to phase rule and titration curves.
How are marks divided in the BCHCT 135 exam?
The paper has 14 questions of 5 marks each. Part A (Q1 to Q7) covers solutions, phase equilibrium, conductance and electrochemistry, and Part B (Q8 to Q14) covers carboxylic acids, amines, peptides and carbohydrates. You answer any five from each part in separate answer sheets, giving 10 answers, 50 marks and 2 hours of writing time.
Are the numericals solved step by step?
Yes. Every numerical in the file starts from the governing law, such as Raoult's law for ideal solutions, then substitutes the given values with units and ends with a checked result. You can see the method in Q1(b) on this page, where both pure-component vapour pressures are put back into the two mixtures to confirm the totals given in the question.
Does the solved file help with the BCHCL 136 lab?
It helps with the theory behind the lab, not with the lab record itself. BCHCL 136 experiments on the phenol-water CST, the effect of impurities on CST, conductometric and potentiometric titrations and the analysis of carboxylic acids link directly to BCHCT 135 questions in the June 2026 paper. The practical index on this page maps each experiment to the question it supports.
Which block carries the most weight in June 2026?
Block 1, Solutions and Phase Equilibrium, carries the most weight in Part A. It supplies Q1, Q2, Q3 and Q4(a), worth 19 of the 35 marks printed in Part A. In Part B, Block 4 on peptides, proteins and carbohydrates supplies Q12, Q13, Q14 and the glucose reaction in Q8, so both blocks deserve extra revision time before the exam.
Who wrote and reviewed the BCHCT 135 answers?
The answers were written by Prateek Talwar and reviewed by Sheetal Kirola of Unnati Educations. Each answer was checked against the matching unit of the official eGyanKosh course material and against the exact wording of the June 2026 paper. Numerical answers end with a check against the data given in the question, so the figures and units stay consistent.
13. Who Wrote and Checked the BCHCT 135 Answers
The BCHCT 135 answers were written by Prateek Talwar and reviewed by Sheetal Kirola.
Prateek Talwar, founder of Unnati Educations, leads the IGNOU science solved-paper series and prepares answers from the course blocks and the official term-end paper. Sheetal Kirola, Academic Head (M.Ed.), checks every formula, substitution and unit against the matching eGyanKosh unit before release.