Q1 · 2005-2021 · 2 marks
Triplet superphosphate is made by treating phosphate rock with
- (a) conc. \mathrm{H}_{2} \mathrm{SO}_{4}
- (b) conc. \mathrm{HNO}_{3}
- (c) conc. HCl
- (d) conc. \mathrm{H}_{3} \mathrm{PO}_{4}
Show answer
Answer: (d)
GATE Chemistry (CY) — Main Group Elements previous year questions
26 questions · 2001–2005 · all with verified answer · last checked 2026-11-06
Q2 · 2005-2021 · 2 marks
The incorrect statement regarding carboranes is that
- (a) carbon tends to adopt the position of the lowest coordination number on the polyhedron
- (b) CH groups tend to be more positive than BH groups with the same coordination number
- (c) carbon tends to keep as close as possible to other carbon atoms
- (d) generally, arachno – carboranes are less stable thermally than the corresponding closo – carboranes
Show answer
Answer: (b)
Q3 · 2005-2021 · 2 marks
\mathrm{Mg}_{6} \mathrm{Si}_{4} \mathrm{O}_{10}(\mathrm{OH})_{8} is commercially known as
- (a) asbestos
- (b) water-glass
- (c) soda-glass
- (d) zeolite
Show answer
Answer: (a)
Q4 · 2005-2021 · 2 marks
The series with the orrect order of decreasing ionic size is
- (a) \mathrm{K}^{+}>\mathrm{Ca}^{2+}>\mathrm{S}^{2-}>\mathrm{Cl}^{-}
- (b) \mathrm{S}^{2-}>\mathrm{Cl}^{-}>\mathrm{K}^{+}>\mathrm{Ca}^{2+}
- (c) \mathrm{K}^{+}>\mathrm{Cl}^{-}>\mathrm{Ca}^{2+}>\mathrm{S}^{2-}
- (d) \mathrm{Cl}^{-}>\mathrm{K}^{+}>\mathrm{S}^{2-}>\mathrm{Ca}^{2+}
Show answer
Answer: (b)
Q5 · 2005-2021 · 2 marks
The Lewis acid character of \mathrm{BF}_{3}, \mathrm{BCl}_{3} and \mathrm{BBr}_{3} follows the order
- (a) \mathrm{BF}_{3}<\mathrm{BBr}_{3}<\mathrm{BCl}_{3}
- (b) \mathrm{BCl}_{3}<\mathrm{BBr}_{3}<\mathrm{BF}_{3}
- (c) \mathrm{BF}_{3}<\mathrm{BCl}_{3}<\mathrm{BBr}_{3}
- (d) \mathrm{BBr}_{3}<\mathrm{BCl}_{3}<\mathrm{BF}_{3}
Show answer
Answer: (c)
Q6 · 2005-2021 · 2 marks
The reaction of \mathrm{Al}_{4} \mathrm{C}_{3} with water leads to the formation of
- (a) methane
- (b) propyne
- (c) propene
- (d) propane
Show answer
Answer: (a)
Q7 · 2005-2021 · 2 marks
The correct statement about \mathrm{C}_{60} is
- (a) \mathrm{C}_{60} is soluble in benzene
- (b) \mathrm{C}_{60} does not react with tert – butyllithium
- (c) \mathrm{C}_{60} is made up of 10 five – membered and 15 six – membered rings
- (d) two adjacent five – membered rings share a common edge.
Show answer
Answer: (a)
Q8 · 2005-2021 · 2 marks
The reaction of phosgene with an excess of \mathrm{NH}_{3} produces
- (a) \mathrm{HN}=\mathrm{C}=\mathrm{O}
- (b) \mathrm{H}_{2} \mathrm{~N}-\mathrm{C}(\mathrm{Cl})=\mathrm{O}
- (c) \left(\mathrm{H}_{2} \mathrm{~N}\right)_{2} \mathrm{C}=\mathrm{O}
- (d) \left(\mathrm{H}_{2} \mathrm{~N}\right)_{2} \mathrm{CCl}_{2}
Show answer
Answer: (c)
Q9 · 2005-2021 · 2 marks
The coordination number of the \mathrm{Ba}^{2+} ins in barium fluoride is 8 . The coordination number of the fluorie ion is:
- (a) 8
- (b) 4
- (c) 1
- (d) 2 .
Show answer
Answer: (b)
Q10 · 2005-2021 · 2 marks
The Lewis acidity of \mathrm{BF}_{3} is less than \mathrm{CBl}_{3} even though fluorine is more electronegative than chlorine. It is due to
- (a) stronger 2\mathrm{p}\,(\mathrm{B})-2\mathrm{p}\,(\mathrm{F})\,\sigma – bonding
- (b) stronger 2\mathrm{p}\,(\mathrm{B})-2\mathrm{p}\,(\mathrm{F})\,\pi – bonding
- (c) stronger 2\mathrm{p}\,(\mathrm{B})-2\mathrm{p}\,(\mathrm{Cl})\,\sigma – bonding
- (d) stronger 2\mathrm{p}\,(\mathrm{B})-2\mathrm{p}\,(\mathrm{Cl})\,\pi – bonding
Show answer
Answer: (b)
Q11 · 2005-2021 · 2 marks
Among the following pentachlorides the one which does not exist due to the ‘inertpair effect’ is
- (a) \mathrm{PCl}_{5}
- (b) \mathrm{BiCl}_{5}
- (c) \mathrm{SbCl}_{5}
- (d) \mathrm{AsCl}_{5}
Show answer
Answer: (b)
Q12 · 2005-2021 · 2 marks
The reaction of solid \mathrm{XeF_2} with \mathrm{AsF_5} in 1:1 ratio affords
- (a) \mathrm{XeF_4} and \mathrm{AsF_3}
- (b) \mathrm{XeF_6} and \mathrm{AsF_3}
- (c) [\mathrm{XeF}]^+[\mathrm{AsF_6}]^-
- (d) [\mathrm{Xe_2F_3}]^+[\mathrm{AsF_6}]^-
Show answer
Answer: (a)
Q13 · 2005-2021 · 2 marks
The total charge on pentaphosphate anion is:
- (a) -5
- (b) -3
- (c) -7
- (d) -9
Show answer
Answer: (c)
Q14 · 2005-2021 · 2 marks
The enthalpies of hydration of \mathrm{Ca}^{2+}, \mathrm{Mn}^{2+} and \mathrm{Zn}^{2+} follow the order
- (a) \mathrm{Mn}^{2+}>\mathrm{Ca}^{2+}>\mathrm{Zn}^{2+}
- (b) \mathrm{Zn}^{2+}>\mathrm{Ca}^{2+}>\mathrm{Mn}^{2+}
- (c) \mathrm{Mn}^{2+}>\mathrm{Zn}^{2+}>\mathrm{Ca}^{2+}
- (d) \mathrm{Zn}^{2+}>\mathrm{Mn}^{2+}>\mathrm{Ca}^{2+}
Show answer
Answer: (d)
Q15 · 2005-2021 · 2 marks
Among the following substituted silanes, the one that gives cross-linked silicone polymer upon hydrolysis is
- (a) \left(\mathrm{CH}_{3}\right)_{4}\mathrm{Si}
- (b) \mathrm{CH}_{3}\mathrm{SiCl}_{3}
- (c) \left(\mathrm{CH}_{3}\right)_{2}\mathrm{SiCl}_{2}
- (d) \left(\mathrm{CH}_{3}\right)_{3}\mathrm{SiCl}
Show answer
Answer: (b)
Q16 · 2005-2021 · 2 marks
Among the following donors, the one that forms most stable adduct with the Lewis acid \mathrm{B}(\mathrm{CH}_{3})_{3} is:
- (a) 4-methylpyridine
- (b) 2,6-dimethylpyridine
- (c) 4-nitropyridine
- (d) 2,6-di-tert-butylpyridine
Show answer
Answer: (a)
Q17 · 2005-2021 · 2 marks
The increasing order of melting points of the halides \mathrm{NaCl}, \mathrm{CuCl} and NaF is:
- (a) \mathrm{CuCl}<\mathrm{NaCl}<\mathrm{NaF}
- (b) \mathrm{NaF}<\mathrm{NaCl}<\mathrm{CuCl}
- (c) \mathrm{NaF}<\mathrm{CuCl}<\mathrm{NaCl}
- (d) \mathrm{CuCl}<\mathrm{NaF}<\mathrm{NaCl}
Show answer
Answer: (a)
Q18 · 2001-2022 · 2 marks
The number of S-S bonds in \mathrm{H}_{2} \mathrm{~S}_{5} \mathrm{O}_{6} is ____
Show answer
Answer: 4
Q19 · 2005-2021 · 2 marks
\mathrm{BCl}_{3} and \mathrm{NH}_{4} \mathrm{Cl} were heated at 140^{\circ} \mathrm{C} to give compound X , which when treated with \mathrm{NaBH}_{4} gave another compound Y . Compounds X and Y are
- (a) \mathrm{X}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{3} \mathrm{Cl}_{3} and \mathrm{Y}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{6}
- (b) \mathrm{X}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{9} \mathrm{Cl}_{3} and \mathrm{Y}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{6}
- (c) \mathrm{X}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{3} \mathrm{Cl}_{3} and \mathrm{Y}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{12}
- (d) \mathrm{X}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{Cl}_{6} and \mathrm{Y}=\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{6}
Show answer
Answer: (a)
Q20 · 2005-2021 · 2 marks
Ammonolysis of \mathrm{S}_{2} \mathrm{Cl}_{2} in an inert solvent gives
- (a) \mathrm{S}_{2} \mathrm{~N}_{2}
- (b) \mathrm{S}_{2} \mathrm{~N}_{2} \mathrm{Cl}
- (c) \mathrm{S}_{2} \mathrm{~N}_{2} \mathrm{H}_{4}
- (d) \mathrm{S}_{4} \mathrm{~N}_{4}
Show answer
Answer: (d)
Q21 · 2005-2021 · 2 marks
The reaction of \mathrm{P}_{2} \mathrm{O}_{5} with \mathrm{HNO}_{3} and \mathrm{HClO}_{4}, respectively, gives
- (a) \mathrm{NO}_{2} and \mathrm{ClO}_{2}
- (b) \mathrm{N}_{2} \mathrm{O}_{5} and \mathrm{Cl}_{2} \mathrm{O}_{6}
- (c) \mathrm{N}_{2} \mathrm{O}_{3} and \mathrm{Cl}_{2} \mathrm{O}_{7}
- (d) \mathrm{N}_{2} \mathrm{O}_{5} and \mathrm{Cl}_{2} \mathrm{O}_{7}
Show answer
Answer: (d)
Q22 · 2005-2021 · 2 marks
In cyclophosphazenes \left(\mathrm{NPX}_{2}\right)_{3}(\mathrm{X}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br} and Me), the strength of \mathrm{P}-\mathrm{N} \pi- bond varies with X in the order
- (a) \mathrm{F}>\mathrm{Cl}>\mathrm{Br}>\mathrm{Me}
- (b) \mathrm{Me}>\mathrm{F}>\mathrm{Cl}>\mathrm{Br}
- (c) \mathrm{Br}>\mathrm{Cl}>\mathrm{F}>\mathrm{Me}
- (d) \mathrm{Me}>\mathrm{Br}>\mathrm{Cl}>\mathrm{F}
Show answer
Answer: (a)
Q23 · 2005-2021 · 2 marks
The reaction of \mathrm{PCl}^{3} with PhLi in 1: 3 molar ratio yields X as one of the products, which on further treatment with \mathrm{CH}_{3} I gives Y. The reaction of Y with n-BuLi gives product Z. The product X, Y and Z respectively, are
- (a) \left[\mathrm{PPh}_{4}\right] \mathrm{Cl},\left[\mathrm{Ph}_{2} \mathrm{P}=\mathrm{CH}_{2}\right] and \mathrm{Ph}_{2} \mathrm{P}(\mathrm{n}-\mathrm{Bu})
- (b) \mathrm{PPh}_{3},\left[\mathrm{Ph}_{3} \mathrm{PI}\right]\left(\mathrm{CH}_{3}\right) and \mathrm{Ph}_{2} \mathrm{P}(\mathrm{n}-\mathrm{Bu})_{3}
- (c) \mathrm{PPh}_{3},\left[\mathrm{Ph}_{3} \mathrm{P}\left(\mathrm{CH}_{3}\right)\right] \mathrm{I} and \mathrm{Ph}_{3} \mathrm{P}=\mathrm{CH}_{3}
- (d) \left[\mathrm{PPh}_{4}\right] \mathrm{Cl},\left[\mathrm{Ph}_{3} \mathrm{P}=\mathrm{CH}_{2}\right] and \left[\mathrm{Ph}_{3} \mathrm{P}(\mathrm{n}-\mathrm{Bu})\right] \mathrm{Li}
Show answer
Answer: (c)
Q24 · 2005-2021 · 2 marks
The CORRECT statement about hexagonal boron nitride is:
- (a) It is reactive towards fluorine.
- (b) It has same layer stacking as that of graphite.
- (c) It is a good electrical conductor.
- (d) It has lower thermal stability in air compared to that of graphite.
Show answer
Answer: (c)
Q25 · 2005-2021 · 2 marks
The correct order of Lewis acid strengths of \mathrm{BF}_{2} \mathrm{Cl}, \mathrm{BFClFBr}, \mathrm{BF}_{2} \mathrm{Br} and \mathrm{BFBr}_{2} is:
- (a) \mathrm{BFBr}_{2}>\mathrm{BFClBr}>\mathrm{BF}_{2} \mathrm{Br}>\mathrm{BF}_{2} \mathrm{Cl}
- (b) \mathrm{BFClBr}>\mathrm{BFBr}_{2}>\mathrm{BF}_{2} \mathrm{Cl}>\mathrm{BF}_{2} \mathrm{Br}
- (c) \mathrm{BF}_{2} \mathrm{Cl}>\mathrm{BFClBr}>\mathrm{BF}_{2} \mathrm{Br}>\mathrm{BFBr}_{2}
- (d) \mathrm{BF}_{2} \mathrm{Cl}>\mathrm{BF}_{2} \mathrm{Br}>\mathrm{BFClBr}>\mathrm{BFBr}_{2}
Show answer
Answer: (a)
Q26 · 2005-2021 · 2 marks
Reaction of \mathrm{LiAlH}_{4} with one equivalent of \mathrm{Me}_{3} \mathrm{~N} \cdot \mathrm{HCl} gives a tetrahedral compound, which reacts with another equivalent of \mathrm{Me}_{3} \mathrm{~N} \cdot \mathrm{HCl} to give compound N . The compound N and its geometry, respectively, are:
- (a) \mathrm{LiAlH}_{4} \mathrm{NMe}_{3} and trigonal bipyramidal
- (b) \mathrm{AlH}_{3}\left(\mathrm{NMe}_{3}\right)_{2} and trigonal bipyramidal
- (c) \mathrm{Li}_{2} \mathrm{AlH}_{4} \mathrm{Cl} and square pyramidal
- (d) \mathrm{AlH}_{3}\left(\mathrm{NMe}_{3}\right)_{2} and pentagonal MAIN GROUP ELEMENT
Show answer
Answer: (b)
Prepare with the GATE batch
Every PYQ is discussed live in the batch. See the course or call +91 92121 42427.
Questions from the ABC Question Bank, typed from the official papers. A question whose answer is still under review is not shown.