ISC Chemistry 2025 Specimen Paper with Answers
All 35 questions of the ISC Chemistry 2025 Specimen Paper, in printed order. Open a question to read it in full and see its answer.
- Q1(A)(i) Fill in the blanks by choosing the appropriate word(s) from those given in the brackets: [four, three, remains same, propane… 1 mark · Fill in
- Q1(A)(ii) Fill in the blanks by choosing the appropriate word(s) from those given in the brackets: [four, three, remains same, propane… 1 mark · Fill in
- Q1(A)(iii) Fill in the blanks by choosing the appropriate word(s) from those given in the brackets: [four, three, remains same, propane… 1 mark · Fill in
- Q1(A)(iv) Fill in the blanks by choosing the appropriate word(s) from those given in the brackets: [four, three, remains same, propane… 1 mark · Fill in
- Q1(B)(i) The correct order of the increasing basic nature of Ammonia, Methylamine and Aniline is: 1 mark · MCQ
- Q1(B)(ii) Colligative properties of a solution are: (P) Independent of the nature of solute (Q) Proportional to molecular mass of solute… 1 mark · MCQ
- Q1(B)(iii) According to Markownikoff’s rule, “The negative part of the halogen acid attaches itself with that C atom of an unsymmetrical… 1 mark · MCQ
- Q1(B)(iv) Most of the naturally occurring $\alpha$-amino acids are optically active and have L-configuration. Which of the following amino… 1 mark · MCQ
- Q1(B)(v) Which one of the following complex ions has geometrical isomers? 1 mark · MCQ
- Q1(B)(vi) Tertiary butyl bromide undergoes Wurtz reaction to give 2,2,3,3-tetramethylbutane. Given below are two statements marked… 1 mark · Assertion-reason
- Q1(B)(vii) There is a continuous increase in size among Lanthanoids with an increase in atomic number. Given below are two statements marked… 1 mark · Assertion-reason
- Q1(C) A plant or any other living being maintains a reasonable balance of C-14 (radioactive carbon) in its tissue during its lifetime… 3 marks · Case based
- Q2 The solution of two electrolytes A and B are diluted. $\Lambda_m$ of B increases $1\cdot5$ times while that of A increases 25… 2 marks · Short answer
- Q3 An organic compound [A] which has characteristic odour, reacts with conc. $\text{NaOH}$ to give two compounds [B] and [C]… 2 marks · Short answer
- Q4 Devise a scheme for the synthesis of n-butane using $\text{CH}_3\text{I}$ as the only source of carbon. Is it possible to obtain… 2 marks · Short answer
- Q5 It is generally observed that the rate of a chemical reaction becomes double with every $10^\circ\text{C}$ rise in temperature… 2 marks · Numerical
- Q6 An organic compound [X] of molecular formula $\text{C}_3\text{H}_5\text{N}$, in one reaction produced a primary amine with… 2 marks · Short answer
- Q7 During chemistry class, a teacher wrote $[\text{Ni}(\text{CN})_4]^{2-}$ as a coordination complex ion on the board. The students… 2 marks · Short answer
- Q8 An organic compound ‘X’ with molecular formula $\text{C}_4\text{H}_{10}\text{O}$ is found to be soluble in… 2 marks · Short answer
- Q9(i) Identify the compounds [A] and [B] in the following reactions… 2 marks · Short answer
- Q9(ii) Three organic compounds A, B and C are non cyclic functional isomers of carbonyl compounds with molecular formula… 2 marks · Short answer
- Q10 Calculate the value of $E^\circ_{\text{cell}}$, $E_{\text{cell}}$ and $\Delta G$ that can be obtained from the following cell at… 2 marks · Numerical
- Q11 Write the chemical test to distinguish between the following pairs of compounds. Propan-1-ol and Propan-2-ol Phenol and ethanol 2 marks · Short answer
- Q12 Identify the compounds [A], [B] and [C] in the following reactions… 3 marks · Short answer
- Q13 The molar mass calculated through colligative properties is sometimes different from that of experimentally determined molecular… 3 marks · Short answer
- Q14 Write chemical equations to illustrate the following name reactions. Rosenmund’s reaction Benzoin condensation Perkin’s reaction 3 marks · Short answer
- Q15 Assuming that cyanide is a strong ligand, write the formula of two coordination complex ions with cyanide and iron having… 3 marks · Short answer
- Q16(i) Dry cells are commonly used in clocks, torches, calculators etc. They are the most familiar type of commercial cells. What acts… 3 marks · Short answer
- Q16(ii) Answer the following: What happens to the voltage when the salt bridge is removed from the two half cells and why? Copper… 3 marks · Short answer
- Q17 The structures of glycine and alanine are given below. Show the peptide bond linkage in glycylalanine… 3 marks · Short answer
- Q18 Consider the data given below for the reaction $\text{A} + \text{B} \longrightarrow \text{Product}$ S.No. conc. of [A]… 3 marks · Numerical
- Q19 Phenol, one of the deadliest acids, contains a hydroxy group directly attached to the aromatic ring. A hydroxy group attached to… 5 marks · Short answer
- Q20 Give a reason for each of the following: (a) The purple colour of $\text{KMnO}_4$ disappears in the presence of acidified… 5 marks · Short answer
- Q21(i) Osmosis and osmotic pressure play a very significant role in biological processes. The osmotic pressure of human blood is… 5 marks · Short answer
- Q21(ii) Answer the following: Calculate the boiling point of urea solution when $8\cdot0\text{ g}$ of urea is dissolved in $250\text{ g}$… 5 marks · Short answer