Haloalkanes & Haloarenes · JEE Main previous year questions

2023 7 questions

1. Q842023 · 11 Apr 2023 · Shift 1· Numerical answer

   $\mathrm{KCl}{\mathrm{O}}_3+6FeS{\mathrm{O}}_4+3{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4\to \mathrm{KCl}+3F{\mathrm{e}}_2(\mathrm{S}{\mathrm{O}}_4{)}_3+3{\mathrm{H}}_2\mathrm{O}$ The above reaction was studied at $300\text{ K}$ by monitoring the concentration of $\mathrm{FeS}{\mathrm{O}}_4$ in which initial concentration was $10\text{M}$ and after half an hour became $8.8\text{ M}$. The rate of production of $\mathrm{F}{\mathrm{e}}_2(\mathrm{S}{\mathrm{O}}_4{)}_3$ is ________ $\times 10^{-6}{\text{ mol L}}^{-1}{\text{ s}}^{-1}$ (Nearest integer)

   Show answer

   Answer: 333

2. Q882023 · 11 Apr 2023 · Shift 1· Numerical answer

   Solid fuel used in rocket is a mixture of $\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3$ and $\mathrm{Al}$ (in ratio $1:2$). The heat evolved ($\text{kJ}$) per gram of the mixture is _________. (Nearest integer) Given: $\Delta {\mathrm{H}}_f^{\theta }(\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3)=-1700{\text{ kJ mol}}^{-1}$ $\Delta {\mathrm{H}}_f^{\theta }(\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3)=-840{\text{ kJ mol}}^{-1}$ Molar mass of $\mathrm{Fe}$, $\mathrm{Al}$ and $\mathrm{O}$ are $56$, $27$ and $16{\text{ g mol}}^{-1}$ respectively.

   Show answer

   Answer: 4

3. Q772023 · 11 Apr 2023 · Shift 2

   Which of the following compounds is an example of Freon?

   1. A.${\mathrm{C}}_2{\mathrm{H}}_2{\mathrm{F}}_2$
   2. B.${\mathrm{C}}_2\mathrm{H}{\mathrm{F}}_3$
   3. C.${\mathrm{C}}_2{\mathrm{F}}_4$
   4. D.${\mathrm{C}}_2\mathrm{C}{\mathrm{l}}_2{\mathrm{F}}_4$
   Show answer

   Answer: D

4. Q672023 · 8 Apr 2023 · Shift 2
   
   1. A.$\mathrm{C}>\mathrm{A}>\mathrm{D}>\mathrm{B}$
   2. B.$\mathrm{D}>\mathrm{B}>\mathrm{A}>\mathrm{C}$
   3. C.$\mathrm{A}>\mathrm{B}>\mathrm{D}>\mathrm{C}$
   4. D.$\mathrm{D}>\mathrm{C}>\mathrm{B}>\mathrm{A}$
   Show answer

   Answer: B

5. Q642023 · 30 Jan 2023 · Shift 1

   Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Ketoses give Seliwanoff's test faster than Aldoses. Reason (R) : Ketoses undergo $\beta$-elimination followed by formation of furfural. In the light of the above statements, choose the correct answer from the options given below :

   1. A.(A) is false but (R) is true
   2. B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
   3. C.(A) is true but (R) is false
   4. D.Both (A) and (R) are true and (R) is the correct explanation of (A)
   Show answer

   Answer: C

6. Q702023 · 30 Jan 2023 · Shift 1
   
   1. A.A - IV, B - II, C - III, D - I
   2. B.A - II, B - I, C - IV, D - III
   3. C.A - II, B - I, C - III, D - IV
   4. D.A - III, B - II, C - IV, D - I
   Show answer

   Answer: B

7. Q742023 · 24 Jan 2023 · Shift 1

   Which of the following is true about freons?

   1. A.These are radicals of chlorine and chlorine monoxide
   2. B.These are chemicals causing skin cancer
   3. C.All radicals are called freons
   4. D.These are chlorofluorocarbon compounds
   Show answer

   Answer: D