Chapter-7 p-Block Elements MCQs
Q 1.: Acidity of diprotic acids in aqueous solution increases in the order :
(A) H2S < H2Se < H2Te
(B) H2Se < H2S < H2Te
(C) H2Te < H2S < H2Se
(D) H2Se < H2Te < H2S
Option – A
Q 2.: The statement that is not correct is ;
(A) Hypophosphorous acid reduces silver nitrate to silver
(B) In solid state PCl5 exists as [PCl4]+ , [PCl6]−
(C) Pure phosphine is non-inflammable
(D) Phosphorous acid on heating disproportionate to give metaphosphoric acid and phosphine
Option – C
Q 3.: The species that is not hydrolysed in water is __________
(A) P4O10
(B) BaO2
(C) Mg3N2
(D) CaC2
Option – A
Q 4.: The correct arrangement of following acids of phosphorus in the increasing order of oxidation state of phosphorus is ;
(A) Hypophosphorus acid < Orthophosphoric acid < Pyrophosphoric acid
(B) Hypophosphorus acid < Pyrophosphoric acid < Orthophosphoric acid
(C) Pyrophosphoric acid < Hypophosphorus acid < Orthophosphoric acid
(D) Pyrophosphoric acid < Orthophosphoric acid < Hypophosphorus acid
Option – B
Q 5.: Which among the following group-16 elements exists in more than two allotropic states ?
(A) Polonium
(B) Tellurium
(C) Selenium
(D) Oxygen
Option – C
Q 6.: The mixture of concentrated HCl and HNO3 made in 3 : 1 ratio contains ;
(A) NOCl
(B) NCl3
(C) ClO2
(D) N2O4
Option – A
Q 7.: A hydride of nitrogen which is acidic ;
(A) NH3
(B) N2H2
(C) N2H4
(D) N3H
Option – D
Q 8.: When conc. H2SO4 is heated with P2O5, the acid is converted to :
(A) Sulphur dioxide
(B) Sulphur trioxide
(C) Sulphur
(D) Mixture of Sulphur dioxide and Sulphur trioxide
Option – B
Q 9.: Aqueous solutions of hydrogen sulphide and sulphur dioxide when mixed together, yield ;
(A) Sulphur trioxide and water
(B) Hydrogen and sulphurous acid
(C) Sulphur and water
(D) Hydrogen peroxide and sulphur
Option – C
Q 10.: Which of the following statements is not valid for oxoacids of phosphorus ?
(A) Orthophosphoric acid is used in the manufacture of triple super phosphate
(B) Hypophosphorous acid is a diprotic acid
(C) All oxoacids contain tetrahedral four coordinated phosphorus
(D) All oxoacids contain at least one P=O unit and one P—OH bond oh age group
Option – B
Q 11.: Ammonia, on reaction with excess of chlorine, gives
(A) N4 and NH4Cl
(B) NCl3 and NH4Cl
(C) N2 and HCl
(D) NCl3 and HCl
Option – D
Q 12.: Which one of the following compound is a peroxide ?
(A) NO2
(B) KO2
(C) MnO2
(D) BaO2
Option – D
Q 13.: In pyrophosphoric acid the number of hydroxyl groups are ;
(A) Four
(B) Three
(C) Two
(D) One
Option – A
Q 14.: The oxidation number of phosphorous in cyclotrimetaphosphoric acid is ____
(A) +3
(B) +5
(C) −3
(D) +2
Option – B
Q 15.: Which is not the correct statement ?
(A) The S8 ring is not planar
(B) Oxygen is more electronegative than sulphur
(C) SF4 exists but OF4 does not exist
(D) SO3 and SO32- both have trigonal planar geometry
Option – D
Q 16.: If the supply of oxygen is limited, H2S reacts with O2 to form ________
(A) H2O + S
(B) H2O + SO3
(C) H2O + SO2
(D) H2SO4 + S
Option – A
Q 17.: Bromine water reacts with SO2 to form
(A) HBr and S
(B) H2O and HBr
(C) H2SO4 and HBr
(D) S and H2O
Option – C
Q 18.: The number of P—O bonds in P4O10 is
(A) 8
(B) 12
(C) 16
(D) 18
Option – C
Q 19.: Sulphuric acid reacts with PCl5 to give
(A) Thionyl chloride
(B) Sulphuryl chloride
(C) Sulphur monochloride
(D) Sulphur tetrachloride
Option – B
Q 20.: P4O10 is the anhydride of _____
(A) H3PO2
(B) H3PO3
(C) H4P2O7
(D) H3PO4
Option – D
Q 21.: Ozone can be tested by
(A) Ag
(B) Hg
(C) Zn
(D) Au
Option – B
Q 22.: Caro’s acid is _________
(A) H2S2O3
(B) H2SO5
(C) H2S2O8
(D) H2SO3
Option – B
Q 23.: Which of the following statements regarding ozone is not correct ?
(A) The ozone molecule is angular in shape
(B) The ozone is a resonance hybrid of two structures
(C) The oxygen-oxygen bond length in ozone is identical with that of molecular oxygen
(D) Ozone is used as germicide and disinfectant for the purification of air.
Option – C
Q 24.: Gaseous product obtained on thermal decomposition of (NH4)2Cr2O7 is
(A) N2
(B) NH3
(C) O2
(D) NO
Option – A
Q 25.: For H3PO3, the correct choice is
(A) Dibasic and Reducing
(B) Dibasic and non-reducing
(C) Tribasic and Reducing
(D) Tribasic and non-reducing
Option – A
Q 26.: Phosphorus pentoxide is widely used as
(A) Bleaching agent
(B) Oxidising agent
(C) Reducing agent
(D) Dehydrating agent
Option – D
Q 27.: Which of the following is not correct ? White phosphorus (P4) has
(A) Four lone pair of electrons
(B) PPP angle is 60°
(C) Four P—P single bond
(D) Six P—P single bond
Option – C
Q 28.: KMnO4 is a strong oxidising agent in acidic medium. To provide acidic medium H2SO4 is used instead of HCl. This is because ;
(A) H2SO4 is a stronger acid than HCl
(B) HCl is oxidised by KMnO4 to Cl2
(C) H2SO4 is a dibasic acid
(D) Only H2SO4 is completely ionised
Option – B
Q 29.: Bleaching action of SO3 is due to its _____
(A) Oxidising property
(B) Acidic property
(C) Basic property
(D) Reducing property
Option – D
Q 30.: Thermodynamically, most stable form of phosphorous is _____
(A) Red P
(B) White P
(C) Black P
(D) Yellow P
Option – C
Q 31.: Which of the following salt would give SO2 with hot and dilute H2SO4 and also decolourises Br2 water ?
(A) Na2SO3
(B) NaHSO4
(C) Na2SO4
(D) Na2S
Option – A
Q 32.: Of the following compounds, the most acidic is ;
(A) As2O3
(B) Bi2O3
(C) Sb2O3
(D) P2O5
Option – D
Q 33.: Carbogen is a mixture of ________
(A) CO2 + N2
(B) CO + O2
(C) CO2 + O2
(D) CO + O2 + N2
Option – C
Q 34.: CaCN2 + C is called as :
(A) Nitrolim
(B) Thomas slag
(C) Seyferth-Gilbert reagent
(D) Koser’s reagent
Option – A
Q 35.: A colourless gas with the smell of rotten fish is ______
(A) NH3
(B) PH3
(C) SO2
(D) H2S
Option – B
Q 36.: Which of the following has the highest proton affinity ?
(A) Arsine (AsH3)
(B) Stibine (SbH3)
(C) Phosphine (PH3)
(D) Ammonia (NH3)
Option – D
Q 37.: Which phosphorous react with KOH solution to produce phosphene gas ?
(A) White P
(B) Red P
(C) Black P
(D) Both ‘A’ and ‘C’
Option – A
Q 38.: Which of the following oxide of nitrogen is most thermally stable ?
(A) N2O5
(B) N2O
(C) NO
(D) N2O3
Option – C
Q 39.: The molecular formula of dithionic acid is _______
(A) H2S2O4
(B) H2S2O6
(C) H2S2O5
(D) H2S2O7
Option – B
Q 40.: When PbO2 reacts with concentrated HNO3, the gas evolved is :
(A) NO2
(B) O2
(C) N2
(D) N2O
Option – B