ISC Chemistry 2018 Question Paper with Answers
All 28 questions of the ISC Chemistry 2018 Question Paper, in printed order. Open a question to read it in full and see its answer.
- Q1(a) Fill in the blanks by choosing the appropriate word/words from those given in the brackets: (square pyramidal, electrical, 74… 4 marks · Fill in
- Q1(b) Complete the following statements by selecting the correct alternative from the choices given: (i) During the course of an… 4 marks · Short answer
- Q1(c) Match the following: 4 marks · Match
- Q1(d) Answer the following questions: (i) (1) Why does the density of transition elements increase from Titanium to Copper? (at. no. Ti… 8 marks · Short answer
- Q2(a) Write the rate law expression for the reaction $\text{A} + \text{B} + \text{C} \rightarrow \text{D} + \text{E}$, if the order of… 2 marks · Short answer
- Q2(b) The rate of reaction becomes four times when the temperature changes from $293\text{ K}$ to $313\text{ K}$. Calculate the energy… 2 marks · Numerical
- Q3 How do antiseptics differ from disinfectants? State the role of the following chemicals in the food industry: (i) Sodium benzoate… 2 marks · Short answer
- Q4 An aromatic organic compound [A] on heating with $\text{NH}_3$ and $\text{Cu}_2\text{O}$ at high pressure gives [B]. The compound… 2 marks · Short answer
- Q5 Write the names of the monomers for each of the following polymers: Bakelite Nylon – 2 – nylon – 6 2 marks · Short answer
- Q6 Name the purine bases and pyrimidine bases present in RNA and DNA. 2 marks · Short answer
- Q7(a) How will you obtain the following? (Give balanced equation.) Picric acid from phenol. Ethyl chloride from diethyl ether. 2 marks · Short answer
- Q7(b) How will you obtain the following? (Give balanced equation.) Anisole from phenol. Ethyl acetate from ethanol. 2 marks · Short answer
- Q8 $40\%$ of a first order reaction is completed in $50\text{ minutes}$. How much time will it take for the completion of $80\%$ of… 2 marks · Short answer
- Q9(a) The freezing point of a solution containing $5\cdot85\text{ g}$ of $\text{NaCl}$ in $100\text{ g}$ of water is… 3 marks · Numerical
- Q9(b) An aqueous solution containing $12\cdot48\text{ g}$ of barium chloride ($\text{BaCl}_2$) in $1000\text{ g}$ of water, boils at… 3 marks · Numerical
- Q10 Examine the defective crystal given below and answer the question that follows: $\text{A}^+$ $\text{B}^-$ $\text{A}^+$… 3 marks · Short answer
- Q11 Give reason for each of the following: For ferric hydroxide sol the coagulating power of phosphate ion is more than chloride ion… 3 marks · Short answer
- Q12 For the complex ion $[\text{Fe}(\text{CN})_6]^{3-}$, state: (i) the type of hybridisation. (ii) the magnetic behaviour. (iii) the… 3 marks · Short answer
- Q13(a) Explain why: $\text{Mn}^{2+}$ is more stable than $\text{Fe}^{2+}$ towards oxidation to $+3$ state. (At. no. of $\text{Mn} = 25$… 3 marks · Short answer
- Q13(b) Complete and balance the following chemical equations: $\text{KMnO}_4 + \text{KI} + \text{H}_2\text{SO}_4 \rightarrow$ _____ +… 3 marks · Fill in
- Q14 Arrange the following in the increasing order of their basic strength: $\text{C}_2\text{H}_5\text{NH}_2$… 3 marks · Short answer
- Q15 Name the sulphide ore of Copper. Describe how pure copper is extracted from this ore. 3 marks · Short answer
- Q16(a) Calculate the emf and $\Delta G^\circ$ for the cell reaction at $25^\circ\text{C}$… 5 marks · Short answer
- Q16(b) The specific conductivity of a solution containing $5\text{ g}$ of anhydrous $\text{BaCl}_2$ (mol. wt. $= 208$) in… 5 marks · Short answer
- Q17(a) Explain why: (1) Nitrogen does not form pentahalides. (2) Helium is used for filling weather balloons. (3) ICl is more reactive… 5 marks · Short answer
- Q17(b) Explain why: (1) Mercury loses its meniscus in contact with ozone. (2) Halogens are coloured and the colour deepens on moving… 5 marks · Short answer
- Q18(a) Give balanced equations for the following reactions: (1) Benzaldehyde reacts with hydrazine. (2) Acetic acid reacts with… 5 marks · Short answer
- Q18(b) Write chemical equations to illustrate the following name reactions: (1) Clemmensen’s reduction (2) Rosenmund’s reduction (3) HVZ… 5 marks · Short answer