CBSE Class 12 Chemistry The p Block Elements MCQs Set 04

Question: Industrial name of H₂S₂O₇ is 
(a) pyrosulphuric acid
(b) Marshall ‘s acid
(c) oleum
(d) All of these
Answer: c

Question: Which of the following oxides, at the same concentration when dissolved in water, results in the most acidic solutions ? 
(a) CO₂
(b) B₂O₃
(c) N₂H₅
(d) Li₂O₂
Answer: c

Question: NO₂ is not obtained on heating 
(a) AgNO₃
(c) Cu(NO₃)₂
(b) KNO₃
(d) Pb(NO₃)₂
Answer: b

Question: Hydrolysis of NCI₃ gives NH₃ and X. Which of the following is X ? 
(a) HCIO₄
(b) HCIO₃
(c) HOCI
(d) HCIO₂
Answer: c

Question: Bleaching action of SO₂ is due to its 
(a) oxiclising property
(b) acidic property
(c) basic property
(d) reducing property
Answer: d

Question: Which of the following phosphorus is the most reactive?
(a) Red phosphorus
(b) White phosphorus
(c) Scarlet phosphorus
(d) Violet phosphorus
Answer: b

Question: If NO₂ (N₂O₄ ) is dissolved in NaOH, we get solution of
(a) NaNO₂ 
(b) NaNO₃
(c) mixture of NaNO₂ and NaNO₂ 
(d) NaNO₄
Answer: c

 Question: Reaction of HNO₃ with I, S, P and C gives respectively
(a) HIO₃ , H₂SO₄, H₃PO₄ and CO₂
(b) HIO₃ , H₂SO₄ , H₃PO₃ and CO₂
(c) HIO₂ , H₂SO₄, H₃PO₄ and CO
(d) I₂O₅ , SO₂ , P₂O and CO₂
Answer: a

Question: What are the products obtained when ammonia is reacted with excess chlorine ? 
(a) N₂ and NCI₃
(c) N₂ and NH₄Cl
(b) N₂ and HCl
(d) NCI₃ and HCl
Answer: d

Question: Given are H₃PO₂ , H₃PO₃, H₃PO₄ and H₄P₂O₇ .
Which of the above oxoacids results into two series of salts ? 
(a) H₃PO₂
(b) H₃PO₃
(c) H₃PO₄
(d) H₄P₂O₇
Answer: b

Question: The correct order of acidic nature of oxides is in the order
(a) NO < N₂O < N₂O₃ < NO₂ < N₂O₅
(b) N₂O < NO < N₂O₃ < NO₂ < N₂O₅
(c) N₂O₅ < NO₂ < N₂O₃ < NO < N₂O
(d) N₂O₅ < N₂O₃ < NO₂ < NO < N₂O
Answer: b

Question: Solid N₂O₅ is
(a) ionic
(c) coordinate covalent
(b) covalent
(d) metallic
Answer: a

Question: The bond angle in NF₃ (102.3°) is smaller than NH₃ (107.2°). This is because of
(a) large size of F compared of H
(b) large size of N compared of F
(c) opposite polarity of N in the two molecules
(d) small size of H compared to N
Answer: c

Question: Which is the anhydride of nitric acid ?
(a) NO
(b) NO₂
(c) N₂O₃
(d) N₂O₅
Answer: d

Question: Correct order of decreasing thermal stability is as
(a) NH₃ > PH₃ > AsH₃ > SbH₃ 
(b) PH₃ > NH₃ > AsH₃ > SbH₃
(c) AsH₃ > PH₃ > NH₃ > SbH₃
(d) SbH₃ > AsH₃ > PH₃ > NH₃
Answer: a

Question: An element belongs to group 15 and third period of the periodic table. Its electronic configw-ation will be
(a) ls²2s²2p³
(b) ls²2s²2p⁴
(c) ls²2s²2p⁶3p²3p³
(d) ls²2s²2p⁶3p²3p²
Answer: c

Question: Which one of the following is least covalent in nature?
(a) NF₃
(b) BiF₃ 
(c) PF₃
(d) SbF₃
Answer: b

Question: Which of the following properties is not shown by NO?
(a) It is diamagnetic in gaseous state 
(b) It is a neutral oxide
(c) It combines with oxygen to form nitrogen dioxide
(d) Its bond order is 2.5
Answer: a

Question: Which one of the following pentafluorides cannot be formed? 
(a) PF₅
(b) AsF₅
(c) SbF₅
(d) BiF₅
Answer: d

Question: Thebasicity of H₃PO₄ is 
(a) 2
(b) 3
(c) 4
(d) 5
Answer: b

Question: H₃PO₃ has ………. non-ionisable P- Hbonds.
(a) 3
(b) 1
(c) 2
(d) None of these
Answer: b

Question: What is the product fonned when phosphorus trioxide is dissolved in water ?
(a) HPO₃
(b) H₃PO₄
(c) H₃PO₃
(d) HPO₂
Answer: c

Question: P₄ + 3NaOH + 3H₂O → A + 3NaH₂PO₂ , here A is
(a) NH₃
(b) PH₃
(c) H₃PO₄
(d) H₃PO₃
Answer: b

Question: Which of the following forms vortex ring? 
(a) P₂O₅
(b) PH₃
(c) NH₃
(d) P₄O₁₀
Answer: b

Question: The decreasing values of bond angles from NH₃ (107° )to SbH3 (91° )down the group-15 of the periodic table is due to
(a) increasing bp-bp repulsion
(b) increasing p-orbital character in sp³
(c) decreasing lp-bp repulsion
(d) decreasing electronegativity
Answer: d

Question: Zinc and cold dil. HNO₃ reacts to produce 
(a) NO
(b) NO₂
(c) NH₄NO₃
(d) ZnNO₃
Answer: c

Question: Hypophosphorus acid, H₃PO₂ is
(a) a monobasic acid
(b) a tribasic acid
(c) a dibasic acid
(d) not acidic at all
Answer: a

Question: Among the following, the number of compounds that can react with PCI₅ to give POCl₃ is O₂, CO₂, SO₂ , H₂O ,H₂SO₄, P₄O₁₀ .
(a) 1
(b) 2
(c) 3
(d) 4
Answer: d

Question: Which element is used in the preparation of pesticides ?
(a) Arsenic
(b) Bismuth 
(c) Antimony
(d) Nitrogez
Answer: a

Question: The catalyst used in the manufacture of H₂SO₄ by contact process is 
(a) V₂O₃
(b) V₂O₅
(c) FeO
(d) Cu
Answer: b

Question: In which of the following, NH₃ is not used? 
(a) Tollen ‘s reagent
(b) Nessler’s reagent
(c) Group reagent for the analysis of IV group basic radicals
(d) Group reagent for the analysis of m group basic radicals
Answer: b

Question: The reaction of P₄ with aqueous NaOH gives 
(a) P(OH)₃
(b) P₂O₅
(c) P(OH)₅
(d) PH₃
Answer: d

Question: Which of the following pairs is obtained on heating anunonium dichromate ?
(a) N₂ and H₂O
(b) N₂O and H₂O
(c) NO₂ and H₂O
(d) NO and NO₂
Answer: a

Question: Liquor ammonia is 
(a) ammonium hydroxide
(b) liquefied ammonia gas
(c) concentrated solution of NH₃ in water
(d) a solution of NH₃ in alcohol
Answer: c

Question: Liquor ammonia bottles are opened only after cooling. This is because 
(a) it is a mild explosive
(b) it generates high vapour pressure
(c) Both (a) and (b)
(d) it is a lachrymatory
Answer: c

Question: Red P can be obtained by white P by
(a) heating it with a catalyst in an inert atmosphere
(b) distilling it in an inert atmosphere
(c) dissolving it in CS₂ and crystallising
(d) melting it and pouring the liquid into water
Answer: a

Question: The treatment of Cu with dilute HNO₃ gives 
(a) N₂O
(b) NO
(c) NH₄⁺
(d) NO₂
Answer: b

Question: NaNH₂ + N₂O → X + NaOH + NH₃ .What is the X ?
(a) N₃Ni
(c) NaN₃
(b) Na₃N
(d) None of these
Answer: c

Question: The sides of safety matches contains
(a) red phosphorus + sand powder
(b) P₄S₃
(c) Ca₃ (PO)₄ + glass pieces
(d) KClO₃ , KNO₃, sulphur + antimony
Answer: a

Question: SO₂ doesnotactas
(a) bleaching agent
(b) oxidising agent
(c) reducing agent
(d) dehydrating agent
Answer: d