Practical & Analytical Chemistry · JEE Main previous year questions

2021 4 questions

1. Q652021 · 27 Jul 2021 · Shift 2

   To an aqueous solution containing ions such as $\mathrm{A}{\mathrm{l}}^{3+}$, $\mathrm{Z}{\mathrm{n}}^{2+}$, $\mathrm{C}{\mathrm{a}}^{2+}$, $\mathrm{F}{\mathrm{e}}^{3+}$, $\mathrm{N}{\mathrm{i}}^{2+}$, $\mathrm{B}{\mathrm{a}}^{2+}$ and $\mathrm{C}{\mathrm{u}}^{2+}$ was added conc. $\mathrm{HCl}$, followed by ${\mathrm{H}}_2\mathrm{S}$. The total number of cations precipitated during this reaction is/are :

   1. A.1
   2. B.3
   3. C.4
   4. D.2
   Show answer

   Answer: A

2. Q652021 · 20 Jul 2021 · Shift 1

   An inorganic Compound 'X' on treatment with concentrated ${\text{H}}_2{\text{SO}}_4$ produces brown fumes and gives dark brown ring with ${\text{FeSO}}_4$ in presence of concentrated ${\text{H}}_2{\text{SO}}_4$. Also Compound 'X' gives precipitate 'Y', when its solution in dilute $\text{HCl}$ is treated with ${\text{H}}_2\text{S}$ gas. The precipitate 'Y' on treatment with concentrated ${\text{HNO}}_3$ followed by excess of ${\text{NH}}_4\text{OH}$ further gives deep blue coloured solution, Compound 'X' is :

   1. A.$\text{Co}({\text{NO}}_3{)}_2$
   2. B.$\text{Pb}({\text{NO}}_2{)}_2$
   3. C.$\text{Cu}({\text{NO}}_3{)}_2$
   4. D.$\text{Pb}({\text{NO}}_3{)}_2$
   Show answer

   Answer: C

3. Q622021 · 26 Feb 2021 · Shift 2

   Ceric ammonium nitrate and $\mathrm{CHC}{\mathrm{l}}_3$/alc. KOH are used for the identification of functional groups present in _________ and _________ respectively.

   1. A.amine, alcohol
   2. B.alcohol, phenol
   3. C.alcohol, amine
   4. D.amine, phenol
   Show answer

   Answer: C

4. Q762021 · 26 Feb 2021 · Shift 2

   Seliwanoff test and Xanthoproteic test are used for the identification of ___________ and ________ respectively.

   1. A.ketoses, proteins
   2. B.proteins, ketoses
   3. C.aldoses, ketoses
   4. D.ketoses, aldoses
   Show answer

   Answer: A