CBSE Questions for Class 12 Engineering Chemistry The P-Block Elements Quiz 10 - MCQExams.com

An element is oxidised by fluorine and not by chlorine. Identify the element.
  • Sodium
  • Aluminium
  • Oxygen
  • Sulphur
When plants and animals decay, the organic nitrogen is converted into inorganic nitrogen. The inorganic nitrogen is in the form of:
  • ammonia
  • elements of nitrogen
  • nitrates
  • nitrides
The gas produced from thermal decomposition of $$Pb(NO_3)_2$$ is:
  • oxygen
  • nitric oxide
  • ammonia
  • nitrogen
The most abundant element in the earths crust by weight is:
  • $$Si$$
  • $$Al$$
  • $$O$$
  • $$Fe$$
The nitride salt of $$Ca$$ when treated with $$H_{2}O$$ gives:
  • $$N_{2}$$
  • $$CaO$$
  • $$CaH_{2}$$
  • $$NH_{3}$$
Which of the following noble gases has the highest positive electron gain enthalpy value?
  • Helium
  • Krypton
  • Argon
  • Neon
  • Xenon
The catalyst used in the manufacture of nitric acid by Ostwald's process is: 
  • $$V_2O_5$$
  • $$Pt$$
  • $$Mo$$
  • $$Fe$$
Which product will be obtained in the following reaction?
$$P_4(s) + 3NaOH(ag) + 3H_2O(l) \rightarrow $$ 
  • $$PH_3(g) + 3NaH_2P0_2 (aq)$$
  • $$PH_3 (g) + 3Na_2 HPO_2 (aq)$$
  • $$2PH_3(g) 3Na_2 HPO_2 (aq)$$
  • $$2PH_3(g) + 3NaH_2 PO_2 (aq)$$
In the Haber process of synthesis of $$NH_3$$,  which of the following statement is correct?
  • $$Mo$$ acts as a catalyst and $$Fe$$ as a promoter
  • $$Fe$$ acts as a catalyst and $$Mo$$ as a promoter
  • $$Fe$$ acts as inhibitor and $$Mo$$ as a catalyst
  • $$Fe$$ acts as promoter and $$Mo$$ as autocatalyst
Which one of the following statements is incorrect?
  • All halogens have weaker X-X bond than X- X' bond, in interhalogens (except F-F bond in fluorine)
  • Radius ratio between iodine and fluorine (among halogens) is maximum
  • Interhalogen compounds are more reactive than halogen compounds
  • Among interhalogen compounds, maximum number of atoms are present in iodine fluoride
Hydrolysis of $$N{ Cl }_{ 3 }$$ gives $$N{ H }_{ 3 }$$ and $$X$$, which of the following is $$X$$?
  • $$HCl{ O }_{ 4 }$$
  • $$HCl{ O }_{ 3 }$$
  • $$HOCl$$
  • $$HCl{ O }_{ 2 }$$
The maximum covalency of nitrogen is
  • $$3$$
  • $$4$$
  • $$5$$
  • $$6$$
 Which of the following phosphorus is the most reactive?
  • Red phosphorus
  • White phosphorus
  • Scarlet phosphorus
  • Violet phosphorus
Noble gas are adsorbed by:
  • anhydrous calcium chloride
  • ferric hydroxide
  • concentrated $${ H }_{ 2 }S{ O }_{ 4 }$$
  • activated coconut charcoal
Platinum is used as a catalyst in:
  • oxidation of ammonia to form nitric acid
  • hydrogenation of oils 
  • production of synthetic rubber
  • synthesis of methanol
In pyrophosphoric acid, $${ H }_{ 4 }{ P }_{ 2 }{ O }_{ 7 }$$, number of $$\sigma -$$ and $$d\pi -p\pi $$ bonds respectively are
  • $$8$$ and $$2$$
  • $$6$$ and $$2$$
  • $$12$$ and zero
  • $$12$$ and $$2$$
In the Haber process for the industrial manufacturing of ammonia involving the reaction
$${ N }_{ 2 }(g)+3{ H }_{ 2 }(g)\rightleftharpoons 2{ NH }_{ 3 }(g)$$ at $$200atm$$ pressure in the presence of a catalyst, a temperature of about $${ 500 }^{ o }C$$ is used. This is considered as optimum temperature for the process because:
  • yield is maximum at this temperature
  • catalyst is active only at this temperature
  • energy needed for the reaction is easily obtained at this temperature
  • rate of the catalytic reaction is fast enough while the yield is also appreciable for this exothermic reaction at this temperature
Which can do glass etching?
  • $$HI{ O }_{ 4 }$$
  • $$Si{ F }_{ 4 }$$
  • $$HF$$
  • $$H{ NO }_{ 3 }$$
The oxidation state of nitrogen in dinitrogen trioxide is:
  • $$+1$$
  • $$+2$$
  • $$+3$$
  • $$+4$$
Which compound of nitrogen is formed when $$CaNH$$ reacts with hot water?
  • $$NH_{3}$$
  • $$N_{2}O$$
  • $$NH_{2}NH_{2}$$
  • $$NO_{2}$$
The heat of atomisation of $${ P }_{ 2 }{ H }_{ 4 } (g)$$ and $${ P }{ H }_{ 3 } (g)$$ are 355 kcal/mol and 228 kcal/mol respectively. The energy of $$P-P$$ bond is:
  • $$102\ kcal\ { mol }^{ -1 }$$
  • $$31\ kcal\ { mol }^{ -1 }$$
  • $$26\ kcal\ { mol }^{ -1 }$$
  • $$204\ kcal\ { mol }^{ -1 }$$
Consider the equilibrium $$NH_{4}Cl (s)\rightleftharpoons NH_{3}(g) + HCl(g)$$. An inert gas is added to the system at constant volume and temperature. The correct statement(s) is/ are:
  • the partial pressures of $$NH_{3}$$ and $$HCl$$ in the system will increase
  • the partial pressures of $$NH_{3}$$ and $$HCl$$ in the system will remain the same
  • the partial pressures of $$NH_{3}$$ and $$HCl$$ in the system will decrease
  • the entropy of the system will increase
Which gas is produced when calcium nitride $$(Ca_{3}N_{2})$$ is hydrolyzed by water?
  • $$N_{2}$$
  • $$NH_{3}$$
  • $$H_{2}$$
  • $$O_{2}$$
Formation of ammonia will be favorable in the following cases(s):
$$N_2(g)\,+\,3H_2(g)\rightarrow2NH_3(g)$$      $$\Delta H\,<\,0$$
  • Addition of inert gas at constant volume
  • Decreasing the volume of the container
  • Addition of inert gas at constant pressure
  • Increasing the pressure
The electronic configuration of few elements is given below. Mark the statement which is not correct about these elements.
(i) $$1s^{2} 2s^{2} 2p^{6} 3s^{1}$$
(ii) $$1s^{2} 2s^{2} 2p^{5}$$
(iii) $$1s^{2}2s^{2}2p^{6}$$
(iv) $$1s^{2}2s^{2}2p^{3}$$
  • (i) is an alkali metal.
  • (iii) is a noble metal.
  • (i) and (ii) form ionic compounds.
  • (iv) has high ionisation enthalpy.
The electronic configuration of four atoms are given in brackets:
L : ($$1s^2\,2s^2\,2p^1$$);                    M : ($$1s^2\,2s^2\,2p^5$$);
Q : ($$1s^2\,2s^2\,2p^6\,3s^1$$);             R : ($$1s^2\,2s^2\,2p^2$$).

The element that would most readily form a diatomic molecule is :
  • Q
  • M
  • R
  • L
Which product will obtained in the following reaction?
Reaction: $${ P }_{ { 4 }_{ (a) } }+3Na{ OH }_{ (aq) }+3{ H }_{ 2 }{ O }_{ (l) }\quad \longrightarrow $$
  • $${ PH }_{ { 3 }_{ (a) } }+3{ Na }_{ 2 }H{ PO }_{ { 2 }_{ (aq) } }\quad $$
  • $${ PH }_{ { 3 }_{ (a) } }+3Na{ H }_{ 2 }{ PO }_{ { 2 }_{ (aq) } }\quad $$
  • $$2{ PH }_{ { 3 }_{ (a) } }+3{ Na }_{ 2 }H{ PO }_{ { 2 }_{ (aq) } }$$
  • $$ 2{ PH }_{ { 3 }_{ (a) } }+3Na{ H }_{ 2 }{ PO }_{ { 2 }_{ (aq) } }\quad $$
Which among the group-$$15$$ elements does not exists as tetra atomic molecule?
  • Nitrogen
  • Phosphorus
  • Arsenic
  • Antimony
Which of the following is used to prepare $$Cl_{2}$$ gas at room temperature from concentrated $$HCl$$?
  • $$MnO_{2}$$
  • $$H_{2}S$$
  • $$KMnO_{4}$$
  • $$Cr_{2}O_{3}$$
Xenon has closed shell configuration but is known to give compounds with fluorine because:
  • Xe atom has large size and lower ionisation potential as compared to other noble gases
  • Xe has unpaired electrons which can form covalent bonds
  • Xe has highest boiling point hence it can form compounds with fluorine
  • fluorine is the smallest element hence it can react with all noble gases
Which of the following factors would favour the formation of ammonia?
  • High pressure
  • Low temperature
  • High volume
  • Low pressure
A cold, green flame can be made by passing carbon dioxide over warm.
  • Grey tin
  • White phosphorous
  • Bronze
  • Green candles
The structure of white phosphorus is:
  • square planar
  • pyramidal
  • tetrahedral
  • trigonal planar
The halogen that is most easily reduced is:
  • $$F_{2}$$
  • $$Cl_{2}$$
  • $$Br_{2}$$
  • $$I_{2}$$
Choose the correct statements from the following?
  • Rhombic sulphur is blue in colour.
  • Rhombic sulphur is soluble in water but insoluble in organic solvents.
  • Rhombic and monoclinic sulphur have $$S_{6}$$ molecules.
  • In Cyclo-$$S_6$$ molecule, the ring adopts chair form.
Which of the following compounds will not give ammonia on heating?
  • $$(NH_{4})_{2}SO_{4}$$
  • $$(NH_{4})_{2}CO_{3}$$
  • $$NH_{4}NO_{2}$$
  • $$NH_{4}Cl$$
Which of the following gases cannot be kept in a glass bottle because it chemically reacts with glass?
  • Sulphur
  • Chlorine
  • Fluorine
  • Methane
Which of the following statements is not correct?
  • All the oxides of halogens are powerful oxidants.
  • The compounds of oxygen and fluorine are not called oxides but fluorides.
  • Oxygen fluorides form oxoacids.
  • In oxyhalides, bonds are mainly covalent due to small difference in electronegativity of oxygen and halogens.
Which compound is prepared by the following reaction?
Xe +$$F_{2}$$ (2:1 volume ratio)$$\overset{Ni}\rightarrow$$at 673 K
  • $$XeF_{4}$$
  • $$XeF_{2}$$
  • $$XeF_{6}$$
  • None of these
Oxygen can be prepared by heating ___________.
  • potassium permanganate
  • methane
  • carbon
  • none of these
In the preparation of $$HNO_{3}$$, we get NO gas by catalytic oxidation of ammonia. The moles of NO produced by the oxidation of two moles of $$NH_{3}$$ will be :
  • 2
  • 3
  • 4
  • 6
Which of the following statements is wrong?
  • Single N-N bond is stronger than the single P-P bond.
  • $$PH_{3}$$ can act as a ligand in the formation of coordination compound with transition elements.
  • $$NO_{2}$$ is paramagnetic in nature.
  • Covalency of nitrogen in $$N_{2}O_{5}$$ is four.
Which of the following statements is not correct about $$XeF_{2}$$?
  • It can be obtained by direct reaction between $$F_{2}$$ and Xe at high pressure.
  • $$XeF_{2}$$ undergoes alkaline hydrolysis to give $$O_{2}$$ and Xe.
  • $$XeF_{2}$$ is a powerful reducing agent.
  • $$XeF_{2}$$ contains two bond pairs and three lone pairs.
The product which is not formed on the heating of potassium permanganate is ________.
  • $$K_2MnO_4$$
  • $$MnO_2$$
  • $$O_2$$
  • $$MnO_4$$
Which factor is most responsible for the increase in boiling points of noble gases from $$He$$ to $$Xe$$?
  • Decrease in $$I.E.$$
  • Monoatomic nature
  • Decrease in polarisability
  • Increase in polarisability
Which of the following substance will have highest boiling point?
  • $$He$$
  • $$CsF$$
  • $${ NH }_{ 3 }$$
  • $$CH{ Cl }_{ 3 }$$
While preparing oxygen from potassium permanganate, the hard glass test tube must be held steady.
  • True
  • False
Which of the molecule does not exist?
  • $$ClF_3$$
  • $$ICl_3$$
  • $$BrF_3$$
  • $$ClI_3$$
Which of the following displaces $$Br_{2}$$ from an aquenous solution containing bromide ions?
  • $$Cl^{-}$$
  • $$Cl_{2}$$
  • $${ I }^{-}_{3}$$
  • $$I_{2}$$
In Haber's process of manufacturing of ammonia:
$${ N }_{ 2 }\left( g \right) +{ 3H }_{ 2 }\left( g \right) \longrightarrow 2{ NH }_{ 3 }\left( g \right) ;{ H }_{ { 25 }^{ 0 }C }^{ o }=-92.2kJ$$
Molecule: $${ C }_{ p }{ JK }^{ -1 }{ mol }^{ -1 }$$
$${ N }_{ 2 }\left( g \right) $$: 29.1
$${ H }_{ 2 }\left( g \right) $$: 28.8
$${ NH }_{ 3 }\left( g \right) $$: 35.1 
If $${ C }_{ p }$$ is independent of temperature, then reaction at $${ 100 }^{ 0 }C$$ as compared to that of $$25^{ 0 }C$$ will be:
  • more endothermic
  • less endothermic
  • more exothermic
  • less exothermic
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 12 Engineering Chemistry Quiz Questions and Answers