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CBSE Questions for Class 12 Engineering Chemistry The P-Block Elements Quiz 11 - MCQExams.com

For the manufacture of ammonia by the reactionN2+3H22NH3+21.9 Kcal, the favorable conditions are:
  • low temperature, low pressure & catalyst
  • low temperature, high pressure & catalyst
  • high temperature, low pressure & catalyst
  • low temperature, high pressure 
Among BF3,N(SiH3)3,N(CH3)3,O(SiH3)2,CF3,CCl3 the number of molecules or molecular ions which have back bonding is:
  • 1
  • 3
  • 4
  • all
Which of the following does not react with xenon to form compunds?
  • OSeF5
  • OTeF5
  • F2
  • N2
The catalyst and promoter respectively used in the Haber's process of industrial synthesis of ammonia are:
  • Mo,V2O5
  • V2O5,Fe
  • Fe,Mo
  • Mo,Fe
Which of the following elements occur free in nature?
  • Nitrogen
  • Phosphorus
  • Arsenic
  • Antimony
When two atoms of chlorine combine to form one molecule of chlorine gas, the energy of the molecule:
  • Greater than that of separate atom
  • Equal to that of separate atom
  • Lower than that of separate atoms
  • None of the above
Which of the following has pπdπ bonding? 
  • NO3
  • CO23
  • BO33
  • SO23
pπdπ bonding is present in:
  • NO3
  • SO23
  • BO33
  • CO23
NH3 is formed in the following steps
I. Ca+2CCaC2    50% yield
II. CaC2+N2CaCN2+C   100% yield
III. CaCN2+3H2O2NH3+CaCO3        50% yield
To obtain 2 moles NH3, calcium required is:
  • 1 mol
  • 2 mol
  • 3 mol
  • 4 mol
Which compound of xenon is not possible ?
  • XeF2
  • XeF4
  • XeF5
  • XeF6
As per Braun's principle, yield of Ammonia will be more in Haber's process under ______, conditions (L= Low; H= high; T= Temp; P= Pressure)
  • LT;LP
  • LT;HP
  • HT;HP
  • HT;LP
In Carius method, of estimation of halogens, 250mg of an organic compound gave 141mg of AgBr. The percentage of bromine in the compound is:
[Atomic mass Ag=108,Br=80 amu]
  • 24
  • 36
  • 8
  • 60
The role of zinc stearate in the process of vulcanisation is:
  • to accelerate the process
  • to slow down the process
  • to stop the process
  • to initiate the process
Which of the following characteristics regarding 7 halogens is not correct? 
  • Ionization energy decreases with increase in atomic number.
  • Electronegativity decreases with increase in atomic number.
  • Electron affinity decreases with increase in atomic number.
  • Enthalpy of fusion increases with increase in atomic number
Which of the following alkyl halides is used as a methylating agent?
  • {C}_{2}{H}_{5}Br
  • {C}_{6}{H}_{5}Cl
  • {CH}_{3}Cl
  • {C}_{2}{H}_{5}Cl
An alkyl halide reacts with alcoholic ammonia in a sealed tube, the product formed will be
  • a primary amine
  • a secondary amine
  • a tertiary amine
  • All of the above
Stability of tetrabromides follows the order :
  • { SeBr }_{ 4 } < { TeBr }_{ 4 } < { PoBr }_{ 4 }
  • { SeBr }_{ 4 } < { PoBr }_{ 4 } < { TeBr }_{ 4 }
  • {PoBr }_{ 4 } < { TeBr }_{ 4 } < { SeBr}_{ 4 }
  • None of the these
In which reaction ammonia acts as an acid?
  • {NH}_{3}+HCl\rightarrow {NH}_{4}Cl
  • {NH}_{3}+{H}^{+}\rightarrow {NH}_{4}^{+}
  • {NH}_{3}+Na\rightarrow Na{NH}_{2}+\cfrac{1}{2}{H}_{2}
  • {NH}_{3} cannot act as an acid
One of the following combinations which illustrates the law of reciprocal proportion?
  • N_{2}O_{3},N_{2}O_{4},N_{2}O_{5}
  • NaCl ,NaBr ,Nal
  • CS_{2} ,CO_{2}, SO_{2}
  • MgO,Mg(OH)_{2}
" N < P < As"
Above order is incorrect for:
  • Electropositivity
  • Covalent radii
  • Size of M^{3-}
  • Acidic nature of M_2O_3 type oxide
The correct order of stability is
  • { N }_{ 2 }>{ N }_{ 2 }^{ + }>{ N }_{ 2 }^{ - }
  • { N }_{ 2 }>{ N }^{ - }_{ 2 }>{ N }_{ 2 }^{ + }
  • { N }_{ 2 }^{ + }>{ N }^{ - }_{ 2 }>{ N }_{ 2 }
  • None of these
A piece of magnesium ribbon was heated to redness in an atmosphere of nitrogen and on cooling water was added the gas evolved was:
  • ammonia
  • hydrogen
  • nitrogen
  • oxygen
An element X forms an oxide XO_3. What is the valency of X?
  • 1
  • 2
  • 3
  • 6
When a mixture of carbon monoxide and chlorine is exposed to sunlight the product formed is:
  • carbon tetrachloride
  • phosgene
  • phosphine
  • carbon chloride
A mixture of NH_4Cl and NaCl can be separated by
  • filtration
  • Distillation
  • Sublimation
  • Decantation
In which one of the following processes is iron used as a catalyst in the preparation of ammonia gas?
  • Bayer's process
  • Haber's process
  • Froth floatation process
  • None of the above
Which element forms maximum multiple bonds?
  • N
  • P
  • As
  • Bi
The bond in compound formed from combination of 14 group and 17 group elements of Periodic table will be ..............
  • Electrovalent bond
  • Co-ordinate bond
  • Van der Walls bond
  • Covalent bond
The most favourable condition for the manufacture of NH_3 is:
  • high temperature and high pressure
  • low temperature and low pressure
  • high temperature and low pressure
  • low temperature and high pressure
In Haber process of  Ammonia production the element used as catalytic promoter to increase the activity of Iron catalyst is .......................
  • NI (Nickel)
  • W (Tungston)
  • V (Vanadium)
  • Mo (Molybednum)
Generally non-metals are non-lustrous. Exception to this property is-
  • Flourine
  • Chlorine
  • Bromine
  • Iodine
Which of the following has more acidic in nature?
  • HClO
  • HClO_2
  • HClO_3
  • HClO_4
An element X combines with hydrogen to form a compound XH_3. The element X is placed on the right side ofthe periodic table. What is true about the element X?
A. Has 3 valence electrons.
B. Is a metal and is solid.
C. Is a non-metal and is a gas.
D. Has 5 valence electrons.
E. XH_3  reacts with water to form a basic compound?
  • A, B and C
  • B,C and D
  • C, D and E
  • E, A and B
Which molecule is relatively more stable?
  • O_2
  • H_2
  • Li_2
  • N_2
Which of the following chalcogen does not make bonds with germanium?
  • Sulfur
  • Selenium
  • Tellurium
  • Polonium
Noble gases have __________ electron affinity.
  • high
  • low
  • zero
  • very low
The wrong statements about \displaystyle NH_{3} is :
  • it is oxidised with oxygen at \displaystyle 700^{\circ}C in the presence of platinum
  • it gives black precipitate with calomel
  • it can be dried by \displaystyle P_{2}O_{5},\ H_{2}SO_{4}\, and\, CaCl_{2}
  • it gives white fumes with HCI
The gas oxygen from thermal decomposition of \displaystyle (NH_4)_2 \, Cr_2 O_7 :
  • Oxygen
  • Nitric oxide
  • Ammonia
  • Nitrogen
Thermodynamically most stable allotrope of phosphorus is_____
  • red 
  • white
  • black
  • yellow
Why does one who drinks alcohol get tempted to drink more alcohol?
  • Because CO_2 increases in liver
  • Because formaldehyde increases in liver
  • Because amount of enzyme P-450 increases in liver
  • Because amount of disulphiram increases in liver
In Ostwald process of manufacturing of HNO_3 catalyst used is:
  • Mo
  • Fe
  • Mn
  • Pt
'Kajal' is produced from:
  • stibnite
  • charcoal
  • carbon black
  • asphalt
The halogen (Group 17 elements):
  • have an electron configuration of a noble gas less seven electrons
  • are highly electro positive
  • show variable oxidation state of -1, +1, +3, +5 and +7 in their various compounds
  • forms a volatile, covalent hydrides HX in which the halogen (X) shows an oxidation state of +1
Which noble gas is most soluble in water?
  • He
  • Ar
  • Ne
  • Xe
Which group of periodic table contains no metal?
  • IA
  • IIIA
  • VIIA
  • VIII
The Group VA element that makes up part of bones and teeth is:
  • N
  • P
  • As
  • Sb
Which one of the following compounds is heated with slaked lime to produce ammonia?
  • {NH}_{4}Cl
  • Na{NO}_{3}
  • K{NO}_{3}
  • Ca{({NO}_{3})}_{2}
Noble gases are absorbed by :
  • Anhydrous calcium chloride
  • Ferric hydroxide
  • Conc. H_2SO_4
  • Activated coconut charcoal
Why are some elements chemically inert?
  • Because their outermost shell is completely empty
  • Because their outermost shell is completely filled
  • Because their innermost shell is completely empty
  • Because their innermost shell is completely filled
The comparatively high b.pt of HF is due to:
  • high reactivity of fluoring
  • small size of hydrogen atom
  • formation of hydrogen bonds and consequent association
  • high IE of flourine
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