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s-Block Elements (Q.B.)12th.pdf
s-Block Elements (Q.B.)12th.pdf
s-Block Elements (Q.B.)12th.pdf
s-Block Elements (Q.B.)12th.pdf
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s-Block Elements (Q.B.)12th.pdf

  1. S-BLOCK ELEMENTS Q.1 Cs+ ions impart violet colour to Bunsen flame. This isdue to the fact that the emitted radiations areof (A)highenergy (B) lower frequencies (C) longer wave-lengths(D)zero wave number Q.2 The compound(s) ofalkaline earthmetals, which are amphoteric innature is/are (A) BeO (B) MgO (C) Be(OH)2 (D) Mg(OH)2 Q.3 Analkalineearthmetal(M)gives asalt withchlorine, whichisinsoluble inwaterat roomtemperaturebut soluble in boilingwater. It also formsaninsoluble sulphate whosemixture witha sulphideofa transition metalis called‘lithopone’ -a white pigment. MetalM is (A) Ca (B) Mg (C) Ba (D) Sr Q.4 The reaction ofan element Awithwater produces combustible gas B and an aqueous solution of C. When another substance D reacts with this solution C also produces the same gas B. D also produces the samegas evenonreactionwithdiluteH2SO4 at roomtemperature. ElementAimparts goldenyellow colour to Bunsenflame. Then,A, B, C and D maybe identified as (A) Na, H2, NaOH and Zn (B) K, H2, KOH and Zn (C) K, H2, NaOH and Zn (D) Ca, H2, CaCOH2 and Zn Q.5 The hydroxide ofalkalineearthmetal, which has the lowest valueofsolubilityproduct (Ksp) at normal temperature (25°C) is (A) Ca(OH)2 (B) Mg(OH)2 (C) Sr(OH)2 (D) Be(OH)2 Q.6 The correct statement is/are (A) BeCl2 is a covalent compound (B) BeCl2 is anelectron deficient molecule (C) BeCl2 canformdimer (D) the hybrid state ofBe in BeCl2 is sp2 Q.7 ) gas smelling pungent ( Z ) ppt Yellow ( Y X T ) ppt Yellow ( HCl . dil CrO K 4 2             IfX gives green flame test. Then, X is (A) MgSO4 (B) BaS2O3 (C) CuSO4 (D) PbS2O3 Q.8 Whichofthe following carbonate ofalkalimetals has theleast thermalstability? (A) Li2CO3 (B) K2CO3 (C) Cs2CO3 (D) Na2CO3 Q.9 The ‘milk ofmagnesia’ used as anantacid is chemically (A) Mg(OH)2 (B) MgO (C) MgCl2 (D) MgO + MgCl2 Q.10 The alkalimetalswhich formnormaloxide, peroxide as wellas super oxides are (A) Na, Li (B) K, Li (C) Li, Cs (D) K, Rb Q.11 The pair ofcompounds, which cannot exist together in asolution is (A) NaHCO3 and NaOH (B) Na2CO3 and NaOH (C) NaHCO3 and Na2CO3 (D) NaHCO3 and H2O Q.12 Mg2C3 + H2O  X (organic compound). Compound X is (A) C2H2 (B) CH4 (C) propyne (D) ethene Q.13 The hydrationenergyofMg2+ is (A) more than that ofMg3+ ion (B) more than that ofNa+ ion (C) more than that ofAl3+ ion (D) more than that ofBe2+ ion
  2. Q.27 The correct order ofsolubilityis (A) CaCO3 < KHCO3 < NaHCO3 (B) KHCO3 < CaCO3 < NaHCO3 (C) NaHCO3 < CaCO3 < KHCO3 (D) CaCO3 < NaHCO3 < KHCO3 Q.28 The complexformation tendencyofalkaline earth metals decreases downthe group because (A) atomicsize increases (B) availabilityofemptyd andf-orbitals increases (C) nuclear charge to volume ratio increases (D) allthe above Q.29 The alkaline earthmetals, whichdo not impart anycolour to Bunsen flame are (A) Be and Mg (B) Mg and Ca (C) Be and Ca (D) Be and Ba Q.30 Y        C 205 , CaSO4·2H2O        C 120 , X. X andYare respectively (A) plaster ofparis, dead burnt plaster (B) dead burnt plaster, plaster ofparis (C) CaO and plaster of paris (D) plaster ofparis, mixture ofgases Q.31 AmetalM readilyforms watersoluble sulphate, and water insoluble hydroxide M(OH)2. Itsoxide MO is amphoteric, hard and having high meltingpoint. The alkaline earthmetalM must be (A) Mg (B) Be (C) Ca (D) Sr Q.32 When K2O is added to water, the solution becomes basic in nature because it contains a significant concentrationof (A) K+ (B) O2– (C) OH– (D) O2 2– Q.33 ) ppt White ( C SO H . dil ) ppt Yellow ( B A D ) ppt White ( 4 2 ) acid acetic in ( CrO K CO Na 4 2 3 2            IfAis the metallic salt, thenthe white ppt. ofD must be of (A)magnesiumoxide (B) red lead (C) bariumcarbonate (D) calciumcarbonate Q.34 (Milky Cloud) C     2 CO A + Na2CO3 —C The chemicalformulae ofAand B are (A) NaOH and Ca(OH)2 (B) Ca(OH)2 and NaOH (C) NaOH and CaO (D) CaO and Ca(OH)2 Q.35 Anaqueous solution ofanhalogensalt ofpotassiumreacts withsame halogenX2 to give KX3, a brown coloured solution, in which halogen exists as X3 – ion, X2 as a Lewis acid and X– as a Lewis base, halogenX is (A)chlorine (B) bromine (C) iodine (D)fluorine Q.36 The correct order ofbasic-strength ofoxides ofalkaline earthmetals is (A) BeO > MgO > CaO > SrO (B) SrO > CaO > MgO > BeO (C) BeO > CaO > MgO > SrO (D) SrO > MgO > CaO > BeO Q.37 Which ofthe following compounds areparamagnetic innature? (A) KO2 (B) K2O2 (C) Na2O2 (D) RbO2 Q.38 The order ofstabilityofchlorides ofalkalimetals is (A) LiCl > NaCl > KCl < CsCl (B) LiCl > NaCl > KCl > CsCl (C) NaCl > KCl > CsCl > LiCl (D) LiCl > NaCl > CsCl > KCl Q.39 NaOH(Solid) + CO     C 200 X; product X is (A) NaHCO3 (B) NaHCO2 (C) HCOONa (D) H2CO3
  3. Q.53 CO Y Cl C X K 1000 about of e temperatur High 2           ; HCl 2 Z O H 2 Y 2    CompoundYis found in polymericchain structure and is an electron deficient molecule.Ymust be (A) BeO (B) BeCl2 (C) Be(OH)2 (D) BeO·Be(OH)2 Q.54 The correct order ofdegree ofhydration ofM+ ions ofalkalimetals is (A) Li+ < K+ < Na+ < Rb+ < Cs+ (B) Li+ < Na+ < K+ < Rb+ < Cs+ (C) Cs+ < Rb+ < K+ < Na+ < Li+ (D) Cs+ < Rb+ < Na+ < K+ < Li+ Q.55 BeCl2 + LiAlH4  X + LiCl +AlCl3 (A) X is LiH (B) X is BeH2 (C) X is BeCl2·2H2O (D) none Q.56 The order ofthermalstabilityofcarbonates ofIIA group is (A) BaCO3 > SrCO3 > CaCO3 > MgCO3 (B) MgCO3 > CaCO3 > SrCO3 > BaCO3 (C) CaCO3 > SrCO3 > BaCO3 > MgCO3 (D) MgCO3 = CaCO3 > SrCO3 = BaCO3 Q.57 A pair ofsubstances which gives the same products on reactionwithwater is (A) Mg and MgO (B) Sr and SrO (C) Ca and CaH2 (D) Be and BeO Q.58 Na2SO4 is water soluble but BaSO4 is insoluble because (A) the hydrationenergyofNa2SO4 ishigher than that ofits lattice energy (B) the hydrationenergyofNa2SO4 is less than that ofits lattice energy (C) the hydrationenergyofBaSO4 is less than that ofits lattice energy (D) the hydrationenergyofBaSO4 is higher than that ofits lattice energy Q.59 Whichofthefollowing is not a anomalouspropertyoflithium? (A) Hydrated lithiumionis the largest among alkalimetals (B) Themeltingand boiling pointsoflithiumare comparativelyhigh (C) Lithiumissofter than that ofother alkalimetals (D) Theionisation potentialand electronegativityoflithiumare higherthanthose ofotheralkalimetals Q.60 The incorrect statement(s) is/are (A) Mg cannot formcomplexes (B) Be can formcomplexes due to a verysmallatomic size (C) thefirst ionisationpotentialofBe is higher thanthat ofMg (D) Mg formsanalkaline hydroxide while Beforms amphoteric oxides Q.61 Thecommercialmethod ofpreparationofpotassiumbyreductionofmoltenKClwithmetallicsodiumat 850°C is based on the fact that (A) potassiumis solid and sodiumdistils offat 850 °C (B) potassiumbeing more volatile anddistils offthus shiftingthe reactionforward (C) sodiumis more reactive than potassiumat 850 °C (D) sodiumhasless affinityto chloride ions in the presence ofpotassiumion Q.62 Be2C + H2O  BeO + X CaC2 + H2O  Ca(OH)2 + Y; then X and Y are respectively (A) CH4, CH4 (B) CH4, C2H6 (C) CH4, C2H2 (D) C2H2, CH4 Q.63 Whichofthefollowing statements are false? (A) BeCl2 is a linear molecule inthe vapour state but it is polymeric inthe solid state (B) Calciumhydrideis called hydrolith. (C) Carbides ofboth Be and Ca react with water to formacetylene (D) Oxides ofboth Be and Ca are amphoteric.
  4. ANSWER KEY Q.1 A Q.2 A,C Q.3 C Q.4 A Q.5 D Q.6 A,B,C Q.7 B Q.8 A Q.9 A Q.10 D Q.11 A Q.12 C Q.13 B Q.14 A Q.15 D Q.16 C Q.17 C Q.18 B Q.19 C Q.20 A,C Q.21 A,B,C Q.22 C Q.23 A Q.24 C Q.25 A,B Q.26 A Q.27 D Q.28 A Q.29 A Q.30 A Q.31 B Q.32 C Q.33 C Q.34 B Q.35 C Q.36 B Q.37 A,D Q.38 C Q.39 C Q.40 B Q.41 D Q.42 A Q.43 D Q.44 C Q.45 A,C Q.46 A Q.47 A Q.48 A Q.49 A Q.50 A Q.51 C Q.52 B Q.53 B Q.54 C Q.55 B Q.56 A Q.57 C Q.58 A,C Q.59 C Q.60 A Q.61 B Q.62 C Q.63 C,D Q.64 A,B,D Q.65 B Q.66 D Q.67 A Q.68 A Q.69 C Q.70 A Q.71 C Q.72 A Q.73 D Q.74 A Q.75 A
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