Alkaline Earth Jr Dpp 30-08-2013

7/23/2019 Alkaline Earth Jr Dpp 30-08-2013

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NARAYANA IIT ACADEMY INDIA

Section : Junior TOPIC: Alkaline Earth Metals Date: 30/08/1

ON!Y ONE OPTION CORRECT

1. When same amount of Be metal is dissolved in excess of HCl and NaOH solutions then

A)2

H

gas is evolved only in HCl solution

B)2

H

gas is evolved only in NaOH solution

C)2

H

gas evolved in both has equal volume under identical conditions

)2

H

gas evolved in both has different volumes under identical conditions

2. !n the atmos"here of ho# many of the follo#ing gases burning $agnesium continue to burn %

A) CO2 B) N2O C) N2 ) &O2 E)

2O

'( A substance #hich gives a bric red flame and breas do#n on heating giving oxygen and bro#n gas is *A) calcium carbonate B) magnesium nitrate C) magnesium carbonate ) calcium nitrate

+( $ortar is a mixture of *

A)

'CaCO

and CaO B) slaed lime and #ater C) slaed lime, sand #ater ) &and -CaO

.( /he substance not liely to contain

'CaCO

is *

A) sea shells B) dolomite C) a marble statue ) calcined gy"sum

0( Which com"ound gives acetylene on reaction #ith #ater *

A)

+ ' Al C

B)

' 2 Mg N

C)2

CaC

)2

CaH

1( Chemical A is used for #ater softening to remove tem"orary hardness( A reacts #ith sodium carbonate to generate

caustic soda( When2

CO

is bubbled through A, it turns cloudy(What is the chemical formula of A%

A)

'CaCO

B) CaO C)

( )2

Ca OH

)

( )' 2Ca HCO

( Ca on ex"osure in moist air forms a layer on surface of *

A)

'CaCO

B)

( )2

Ca OH

C)

( )' 2(CaCO Ca OH

)

CaO

3( &ubstance #hich absorbs2

CO

and violently reacts #ith2

H O

#ith sound is *

A)

'CaCO

B)

CaOC)

2 + H SO

)

ZnO

45( /he com"ound 6 on heating gives a colourless gas( /he residue is dissolved in #ater to obtain

7( 8xcess2

CO

is bubbled through aqueous solution of 7, 9 is formed( 9 on gentle heating gives bac 6( /he

com"ound 6 is

A)

'CaCO

B)

2 ' Na CO

C)+ 2

(2CaSO H O

)

2 ' K CO

44( &etting of "laster of "aris involves *



A) Oxdation #ith atmos"heric oxygen B)combination #ith atmos"heric2

CO

C) dehydration ) hydration to yield another hydrate

42( At high tem"erature, nitrogen combines #ith2

CaC

to give *

A) calcium cyanide B) calcium cyanamide C) calcium carbonate ) calcium nitride

4'( /he ionic carbide is*

A)2

CaC

B) 9nC C)

SiC ) /iC

4+(

2 ' Mg C

reacts #ith #ater forming "ro"yne gas,

+

'C −

ions has*

A) t#o sigma and t#o "i bonds B) three sigma and one "i bondC) t#o sigma and one "i bond ) t#o sigma and three "i bonds

4.( /he fluoride #hich is most soluble in #ater is*

A)2

CaF

B)2

BaF

C)2

SrF

)2

BeF

40( When $gCl2( 0H2O is strongly heated, then it forms *

:A)$gO :B) $g:OH)2 :C) $g:OH)Cl :) $gCl2

41( Amongst the follo#ing hydroxides, the one #hich has the highest value of ; s" at ordinary tem"erature is *

:A) $g:OH)2 :B)Ca:OH)2 :C)&r:OH)2 :<) Ba:OH)2

4( /he thermal stability of BaCO', CaCO', &rCO' and $gCO' decreases in theorder *

:A) BaCO'= &rCO'= $gCO'= CaCO' :B) CaCO'= &rCO'= $gCO'= BaCO'

:C) $gCO'= CaCO'= &rCO'= BaCO' :) BaCO'= &rCO'= CaCO'= $gCO'

43( Calcium imide on hydrolysis gives gas :B) #hich on oxidation by bleaching "o#der gives gas :C)( >as :C) on

reaction #ith magnesium give com"ound :) #hich on hydrolysis gives again a gas :B)( !dentify :B), :C) and

:)(

:A) NH', N2, $g' N2 :B) N2, NH', $gNH

:C) N2, N2O., $g:NO')2 :) NH', NO2, $g:NO2)2

25( Which is not obtained #hen metal carbides react#ith H2O %

:A) Al+C' ? H2O → CH ≡ CH :B) CaC2 ? H2O → CH ≡ CH

:C) $g+C' ? H2O → CH'C @ CH :) Be2C ? H2O → CH+

24( Choose incorrect statement *

:A) BeCO' is e"t in the atmos"here of CO2 since, it is least thermally stable

:B) Be dissolves in alali forming

( )2

4Be OH

−

:C) Be2 forms com"lex ion #ith Na in #hich Be goes #ith cation(

:) Be2 forms com"lex ion #ith Na in #hich Be goes #ith anion(

22( !n "olymeric :BeCl2)n, there are*

:A) three centre t#oelectron bonds :B) three centre threeelectron bonds

:C) t#o centre threeelectron bonds :) t#o centre t#oelectron bonds(

2'( An element A is invariably divalent and its oxide is soluble in excess of NaOH and the cation of A does not :#ith

stable e configuration) have electrons in dsubshell(

:A) Ca :B) Be :C) 9n :) Db

2+( Consider the belo# given statements about alaline earth metals(

:i) &olubility of sul"hates decreases do#n the grou"(

:ii) &olubility of hydroxides decreases do#n the grou"

:iii) /hermal stability of carbonates increases do#n the grou"

:iv) Basic nature of oxides increases do#n the grou"(

/he correct one are(

:A) :i) , :ii) - :iii) :B) :i), :iii) - :iv) :C) :i) - :iv) only :) :ii) only

2.( Which of the follo#ing s"ecies has the least tendency to form nitrides

:A) Na :B) Al :C) $g :) Ei

20( &! * Chlorine gas dis"ro"ortionates is hot and conc( NaOH solution



&!! * NaCl and NaOCl are formed in the above reaction(

:A) :B) :C) :)

21( &! * &u"er oxides of alali metals are "aramagnetic

&!! * &u"er oxides contain the2O−

ion #hich has one un"aired electron in its anti bonding orbital

:A) :B) :C) :)

2( &! */he molar conductance of the follo#ing aqueous ion is Cs?=Fb?= Na?= ; ?= Ei?

&!! * $ore the hydration of cation less the conductivity

:A) :B) :C) :)

23( Choose the incorrect statement

:A) Feducing "o#er in aqueous solution is maximum for Ei metal

:B) 8lectron affinity order O?=O =

2 22O O− −

>

:C) order of oxidation number of oxygen O'= ;O2= BaO2= ; 2O

:) "H of aqueous solution EiCl= BeCl2= $gCl2= AlCl'

'5( /he com"ound insoluble in Acetic acid is:A) CaO :B) CaCO' :C) CaC2O+ :) Ca:OH)2

'4( &! *

26SiF−

is no#n but

26SiCl−

is not

&!! * &iGe of fluorine is small and its lone "air of electrons interacts #ith dorbitals of silicon strongly

:A) :B) :C) :)

'2( &! * /he alali metals can form ionic hydrides #ith contain

( )H

−

ion

&!! * /he alali metals have lo# electronegativity

:A) :B) :C) :)

''( &! * 8ther can be used to extract EiClI from a mixture of EiCl, NaCl and ;Cl

&!! * NaCl, ;Cl are more covalent than EiCl:A) :B) :C) :)

'+( /he conductivity decreases from Ei? salts to Cs? salts in aqueous solution because of

:A) increasing in number( of #ater molecules surrounding the ion is their "rimary shell from Ei? to Cs?

:B) ecrease is no( of #ater molecules surrounding the ion in the secondary layer from Ei ? to Cs?

:C) /he "resence of vacant dorbitals in the valence shells of ; ?, Fb? and Cs?

:) ecrease is no( of #ater molecules surrounding the ion in their "rimary shell from E! ? to Cs?

'.( /he com"ound J6K on heating gives a colour less gas, the residue is dissolved in #ater to obtain J7K( 8xcess CO

is "assed through aq solution of 7 #hen 9 is formed ( 9 on gentle heating gives bac 6, the com"ound 6 is

:A) Na2CO' :B) CaCO' :C) ( )3 2Ca HCO:) NaHCO'

'0( Which of the follo#ing metal form unstable hydroxide u"on reaction #ith NaOH

:A) 9n :B) Db :C) e :) Hg

'1( &!* ;O' is found to be coloured

&!! * /here exist transfer of electron from ; to O in ;O' #hich requires energy and gives rise to absor"tion

s"ectra(

'( &! * Beryllium salts are acidic #hen dissolved in "ure #ater

&!! * BeO bond is very strong thus it #eaens the OH bond in hydrated ion

'3( Which does not dis"ro"ortionates #hen reacts #ith NaOH %

:A) Cl2 :B) D+ :C) Br 2 :) 2



+5( Which of the follo#ing trends are true :/) :or) false :) %

&olubilities

:4) Cs2&O+= Fb2&O+=2 4Li SO

:2) Be&O+L Ca&O+L4BaSO

:')

( ) ( ) ( )2 2 2

Mg OH Ca OH Sr OH> >

:A) // :B) / :C) :) //

+4( !dentify , 8, res"ectively in the follo#ing scheme CaCO'

∆

:A) ? :B)gas

:A) ? H2O → C M C ? B → CaCO' ? H2O

? C

∆

8:gas) M 8 ? H2O ? B →

:A) NH+HCO', NH+Cl,

3NH

:B) NH+HCO', NH',4NH Cl

:C) NaHCO', NH+Cl,

3NH

:) NaHCO' ,

3NH

, CO2

+2(

( )solution

M Alkali metal

?

( ) ( ) ( )+ − + → + 3 3 3x yX NH M NH e NH

$ae out the incorrect statement about the solution

:A) solution has high electric conductivity due to ammoniated electron

:B) dilute solution im"arts co""er BronGe colour

:C) ilute solution is "aramagnetic

:) On the addition of substances lie J!ronK the solution decom"oses and releases H 2 gas

+'( /he reaction of an element A #ith #ater "roduces combustible gas B and an aqueous solution of C(

When another substance reacts #ith this solution C also "roduces the same gas B( also "roduces the same gas even on reaction #ith dilute H2&O+ at room tem"erature( 8lement A im"arts

golden yello# colour to Bunsen flame( /hen A, B, C and may be identified as

:A) Na, H2, NaOH and 9n :B) ;, H2, ;OH and 9n

:C) ;, H2, NaOH and 9n :) Ca, H2, CaCOH2 and 9n

++( Which of the follo#ing have same no(of JK and JK bonds %

!( $g2C' !!( Na2CN2 !!!( NaN' !P( CaC2

:A) ! and !!! :B) !, !! - !!! :C) !!! - !P :) !, !! - !P

+.( $agnesium #ire burns in the atmos"here of CO2 because

:A) $agnesium acts as an oxidiGing agent :B) $agnesium has 2 electrons in the outer most orbit

:C) $agnesium act as a reducing agent and remove oxygen from CO2 :) None

+0( An alaline earth metal :$) gives a salt #ith chlorine, #hich is insoluble in #ater at room tem"erature but solublein boiling #ater( !t also forms an insoluble sul"hate #hose mixture #ith a sul"hide of a transition metal is called

litho"oneI a #hite "igment( $etal $ is

:A) Ca :B) $g :C) Ba :) &r

MORE THAN ONE ANSWER TYPE

+1( &elect the incorrect statement:s) *

:A) &econd "eriod of modern "eriodic table contains maximum number of gaseous elements and sixth "eriod

contains maximum number of solid elements

:B) &r&O+ is the most stable to#ards heat among all the sul"hates of alaline earth metals(

:C) $olten hydrides of all alali metals liberate H 2 gas at anode on electrolysis(

:) /he coordination number of 9n in WurtGite structure is +(



+( Which of the follo#ing is an electron deficient molecule %

A) EiHB)

2 0 B H

C) beryllium hydride "olymer ) dimer of beryllium bromide

+3( Which of the follo#ing statements is :are) not correct for alali metal

:A) /hey al#ays exist in ?4 state in their com"ounds

:B) /heir ions are coloured and "aramagnetic is nature

:C) the alali metal cations have a strong tendency, to get hydrated

:) 8ach alali metal atom is the smallest atom in its "eriod(

.5( Which of the statements are true

:A) NaHCO' and ;HCO' have same crystal structure

:B) On heating Ei2CO' givenEi2O and CO2

:C) Among alali metals, Ei metal has high !8 and !m"art no colour to flame

:) Ei2&O+ does not form alum

.4( Which of the follo#ing com"oundQs do not conduct electricity in their molten state

:A) $gCl2 :B) BeCl2 :C) Be2 :) $g2

KEY

1 C " E D # C $ D % C & C 8 C

' ( 10 A 11 D 1" ( 1 A 1# A 1$ D 1% A

1& D 18 D 1' A "0 A "1 C "" A " ( "# (

"$ A "% C "& A "8 A "' D 0 C 1 " A C # ( $ ( % D & C 8 A ' D #0 (

#1 ( #" ( # A ## ( #$ C #% C #& CD #8 (CD

#' (D $0 (D $1 (C

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Alkaline Earth Jr Dpp 30-08-2013