ISC Chemistry 2025 Question Paper with Answers
All 35 questions of the ISC Chemistry 2025 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 [+2, ethane, tetrahedral, square planar, zero, dry cell, nickel-cadmium cell… 1 mark · Fill in
- Q1(A)(ii) Choose the appropriate word(s) from the bracket [+2, ethane, tetrahedral, square planar, zero, dry cell, nickel-cadmium cell… 1 mark · Fill in
- Q1(A)(iii) Choose the appropriate word(s) from the bracket [+2, ethane, tetrahedral, square planar, zero, dry cell, nickel-cadmium cell… 1 mark · Fill in
- Q1(A)(iv) Choose the appropriate word(s) from the bracket [+2, ethane, tetrahedral, square planar, zero, dry cell, nickel-cadmium cell… 1 mark · Fill in
- Q1(B)(i) Which one of the following can produce the foul smelling compound methyl isocyanide in presence of alcoholic $\text{KOH}$? 1 mark · MCQ
- Q1(B)(ii) The osmotic pressure of a solution: (P) increases with an increase in number of moles of solute. (Q) decreases with an increase… 1 mark · MCQ
- Q1(B)(iii) Which one of the following alcohols is the strongest acid? 1 mark · MCQ
- Q1(B)(iv) Which one of the following does NOT form a silver mirror on heating with Tollen’s reagent? 1 mark · MCQ
- Q1(B)(v) The coordination number and the oxidation state of the central metal 'D' in the complex… 1 mark · MCQ
- Q1(B)(vi) The process of halogenation of benzene takes place in the presence of anhydrous $\text{FeCl}_3$. Given below are two statements… 1 mark · Assertion-reason
- Q1(B)(vii) The $\text{Zr}$-$\text{Hf}$ pair of elements has the same value of atomic radii though $\text{Zr}$ and $\text{Hf}$ are placed in… 1 mark · Assertion-reason
- Q1(C) The rate of a reaction depends on the concentration of reactants. The rate law for a hypothetical reaction… 3 marks · Case based
- Q2 Calculate the number of coulombs required to electroplate $4\cdot75\text{ g}$ of aluminium when electrode reaction is… 2 marks · Numerical
- Q3 An organic compound [A] has molecular formula $\text{C}_7\text{H}_6\text{O}_2$. When compound [A] is treated with… 2 marks · Short answer
- Q4 In the reaction $2\text{NO} + \text{O}_2 \longrightarrow 2\text{NO}_2$, the rate law is… 2 marks · Short answer
- Q5 When an organic compound [A] having molecular formula $\text{C}_4\text{H}_9\text{Br}$ is treated with aqueous $\text{KOH}$, the… 2 marks · Short answer
- Q6 Write a balanced chemical equation for each of the following: Ethyl cyanide is reduced with $\text{LiAlH}_4$. Aniline is treated… 2 marks · Short answer
- Q7 While conducting an experiment on coordination compounds, Shirin observed a white precipitate when $\text{AgNO}_3$ solution was… 2 marks · Short answer
- Q8 Answer the following: Arrange the following in the increasing order of their Acidic strength… 2 marks · Short answer
- Q9(i) Identify the compounds [A], [B], [C] and [D] in the following reaction… 2 marks · Short answer
- Q9(ii) Write chemical equations to convert the following: Benzaldehyde to benzene Benzoic acid to benzaldehyde 2 marks · Short answer
- Q10 Calculate the $E^\circ_{\text{cell}}$ of the following if the cell potential ($E_{\text{cell}}$) is $0\cdot59\text{ V}$. (Given… 2 marks · Numerical
- Q11 Write the chemical test to distinguish between each of the following pairs of compounds: Ethanol and propan-1-al Phenol and… 2 marks · Short answer
- Q12 Identify the compounds [A], [B] and [C] in each of the following reactions… 3 marks · Short answer
- Q13 The scientist van’t Hoff introduced a factor ($i$) to account for the extent of association or dissociation of solutes. It is… 3 marks · Short answer
- Q14 Write chemical equations to illustrate the following name reactions: Finkelstein reaction Williamson’s synthesis Reimer-Tiemann… 3 marks · Short answer
- Q15 According to Crystal-Field Theory, the electronic configuration of complex compound [A] is $t_{2g}^4 e_g^2$ and that of complex… 3 marks · Short answer
- Q16(i) Answer the following questions: By referring to electrochemical series, how can anode and cathode half cells be identified in a… 3 marks · Short answer
- Q16(ii) Answer the following questions: Specific conductance of a solution decreases upon dilution. Why? The emf of a cell should be… 3 marks · Short answer
- Q17 Answer the following: The structure of amino acid exists in the following two forms… 3 marks · Short answer
- Q18 The data given below is for the reaction between $[\text{NO}]$ and $[\text{Cl}_2]$ to form $\text{NOCl}$ at $25^\circ\text{C}$… 3 marks · Numerical
- Q19 Phenol is an aromatic alcohol that is used to prepare many important compounds such as picric acid. Phenol is widely used in… 5 marks · Short answer
- Q20 Give a reason for the following: $\text{Ti}^{3+}$ salts are coloured whereas $\text{Ti}^{4+}$ salts are colourless. [Given… 5 marks · Short answer
- Q21(i) Osmotic pressure is the external pressure which should be applied to stop the flow of solvent into the solution when the two are… 5 marks · Short answer
- Q21(ii) Answer the following questions: An aqueous solution is made by dissolving $10\text{ g}$ of glucose… 5 marks · Short answer