ISC Chemistry 2026 Question Paper with Answers
All 35 questions of the ISC Chemistry 2026 Question Paper, in printed order. Open a question to read it in full and see its answer.
- Q1(A)(i) Choose the appropriate word(s) from the bracket [first, alc. AgCN, primary, decrease, third, increase, zero, Lucas, alc. KCN… 1 mark · Fill in
- Q1(A)(ii) Choose the appropriate word(s) from the bracket [first, alc. AgCN, primary, decrease, third, increase, zero, Lucas, alc. KCN… 1 mark · Fill in
- Q1(A)(iii) Choose the appropriate word(s) from the bracket [first, alc. AgCN, primary, decrease, third, increase, zero, Lucas, alc. KCN… 1 mark · Fill in
- Q1(A)(iv) Choose the appropriate word(s) from the bracket [first, alc. AgCN, primary, decrease, third, increase, zero, Lucas, alc. KCN… 1 mark · Fill in
- Q1(B)(i) Which one of the following is a tetrahedral complex as well as diamagnetic in nature? 1 mark · MCQ
- Q1(B)(ii) When $\text{H}_2\text{S}$ gas is passed through acidified $\text{K}_2\text{Cr}_2\text{O}_7$ solution, the colour of the solution… 1 mark · MCQ
- Q1(B)(iii) Identify the end product [C] in the following sequence of chemical reaction… 1 mark · MCQ
- Q1(B)(iv) Rohit is studying the iodoform reaction by using the following compounds: (P) $\text{CH}_3\text{OH}$ (Q) $\text{CH}_3\text{CHO}$… 1 mark · MCQ
- Q1(B)(v) Which one of the following nitrogen bases is absent in RNA? 1 mark · MCQ
- Q1(B)(vi) Phenols are more acidic than aliphatic alcohols. Given below are two statements marked Assertion and Reason. Read the two… 1 mark · Assertion-reason
- Q1(B)(vii) The depression of freezing point of $0\cdot1$ molal aqueous solution of $\text{MgCl}_2$ is less than that of $0\cdot1$ molal… 1 mark · Assertion-reason
- Q1(C) Kohlrausch observed an interesting pattern between the values of molar conductance at infinite dilution ($\Lambda^\infty_m$) for… 3 marks · Case based
- Q2 A reaction is of first order with respect to reactant [A] and second order with regard to reactant [B]. What is the effect on… 2 marks · Short answer
- Q3 Answer the following: $0\cdot680\text{ g}$ of a compound is dissolved in $15\cdot0\text{ g}$ of benzene and the freezing point of… 2 marks · Numerical
- Q4 Write the IUPAC names of the following complex compounds: $[\text{Pt}(\text{NH}_3)_4\text{Cl}_2]\text{SO}_4$… 2 marks · Short answer
- Q5 Write chemical equations to convert each of the following: Methyl magnesium bromide to propan-2-ol Phenol to benzene 2 marks · Short answer
- Q6 Calculate the value of $\Delta G^\circ$ for the following cell at $25^\circ\text{C}$… 2 marks · Numerical
- Q7 Write chemical reactions for the following named organic reactions: Diazotisation reaction Sandmeyer’s reaction 2 marks · Short answer
- Q8 A first order reaction is $40\%$ complete in $20\text{ minutes}$. Calculate the time required for $90\%$ completion of the same… 2 marks · Numerical
- Q9(i) Write chemical tests to distinguish between the following pairs of compounds: Acetaldehyde and acetone Acetic acid and… 2 marks · Short answer
- Q9(ii) An organic compound [A] having molecular formula $\text{C}_3\text{H}_8\text{O}$ gives turbidity with Lucas reagent within five… 2 marks · Short answer
- Q10 Answer the following: Why is the first ionisation enthalpy of chromium less than that of zinc? (Atomic Number of $\text{Cr} = 24$… 2 marks · Short answer
- Q11 Write chemical equations to convert each of the following: Chlorobenzene to aniline Iodoform to acetylene 2 marks · Short answer
- Q12 Write chemical equations to convert each of the following: Methanol to ethanol Benzene diazonium chloride to phenol Sodium… 3 marks · Short answer
- Q13 Answer the following: Complete and balance the following reactions: (a)… 3 marks · Short answer
- Q14 Answer the following: Give one example each of fibrous protein and globular protein. The structures of two amino acids, glycine… 3 marks · Short answer
- Q15 Write the chemical reactions when: Chlorobenzene is heated with conc. $\text{HNO}_3$ in the presence of conc… 3 marks · Short answer
- Q16 Answer the following: The rate constant of a first order reaction increases five times when the temperature is raised from… 3 marks · Numerical
- Q17(i) Answer the following: The molar conductivity at infinite dilution for… 3 marks · Short answer
- Q17(ii) Answer the following: When a current of $0\cdot75\text{ ampere}$ is passed through a $\text{CuSO}_4$ solution for… 3 marks · Short answer
- Q18 Identify the compounds [A], [B] and [C] in the following reactions… 3 marks · Short answer
- Q19 Answer the following: Calculate the mass of ascorbic acid (molecular mass $= 176\text{ g mol}^{-1}$) to be dissolved in… 5 marks · Numerical
- Q20 Answer the following: What happens when (write chemical equations): (a) Calcium acetate is subjected to dry distillation. (b)… 5 marks · Short answer
- Q21(i) Answer the following: With reference to Valence Bond Theory (VBT), answer the following questions regarding the complex ion… 5 marks · Short answer
- Q21(ii) Answer the following: Write the electronic configuration of the following: (1) $d^4$ (high spin octahedral) (2) $d^6$ (low spin… 5 marks · Short answer