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CSB – 1
s-BLOCK ELEMENTS
Syllabus :
Group-1 and 2 Elements
General introduction, electronic configuration and
general trends in physical and chemical properties
of elements, anomalous properties of the first
element of each group, diagonal relationships.
Preparation and properties of some important
compounds - sodium carbonate, sodium chloride,
sodium hydroxide and sodium hydrogen carbonate;
Industrial uses of lime, limestone, plaster and
cement; Biological significance of Na, K, Mg and
Ca.
Einstein Classes,
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 2
CONCEPTS
C1
Physical Properties of Alkali Metals :
They form univalent positive ion. Their atomic size are maximum in their corresponding periods. They
have very low ionization energies. They bahave as a powerful reducing agents. They are strongly
electropositive elements. Their electronegativity values are lowest in the corresponding periods. They
impart characteristic colours to the flame. They show photosensitive effect. The hydration Enthalpy of
alkali metal ions in decreasing order is Li+ > Na+ > K+ > Rb+ > Cs+. Potassium is lighter than sodium. The
alkali metals do not occur free in nature. This is because they have very low ionization enthalpy and form
electropositive ions. Sodium is less reactive than potassium this is because the ionization enthalpy (iH) of
potassium (496 kJ mol–1) is less than that of sodium (520 kJ mol–1).
C2
Chemical property of alkali metal :
Alkali metals and alkaline earth metals are strong reducing agents themselves, because of this they are not
obtained by chemical reduction process. Note : They act as strong reducing agents because they readily lose
the valence electrons, owing to their low ionisation enthalpy, low heat of atomisation and high heat of
hydration
Reaction of group I Metals
Reaction
1.
2.
3.
2M + 2H2O  2MOH + H2
(hydroxide)
2Li + ½O2  Li2O
2Na + O2  Na2O2
Important Points
1.
All alkali metals react with H2O. The reaction
becomes increasingly violent on decreasing the
group. The Li reacts
gently, sodium melts on
the surface of water and molten even catches fire.
Similarly for K....... Thus Na, K are placed in
kerosene oil.
2.
MOH are strongest bases.
Monoxide is formed by Li and to a small
extent by Na
Peroxide formed by Na and to a small extent by
Li
4.
K + O2  KO2
Superoxide (MO2) formed by K, Rb and Cs.
5.
2M + H2  2MH
Ionic salt-like hydride
6.
3Li + ½N2  Li3N
Only Li forms nitride
7.
2M + X2  2MX
All metals form fluorides, chlorides, bromides
and iodides
8.
2M + 2NH3  2MNH2 + H2
Na(l)  Na+(l) + e—
e— + NH3  NH2— + ½ H2
Na+(am) + e— (am) + NH(l)
 NaNH2(s) + ½H2
where ‘am’ denotes solution in
ammonia
Fe
All the metals form amides. Dilute solutions of
alkali metals in liquid NH3 are dark blue in colour
due to presence of solvated electrons and the
solvated metal ions. If the blue solution is allowed
to stand, the colour slowly fades and becomes
copper colour owing to the formation of metal
amide.
9.
M + X2  2MX
X2  F2, Cl2, Br2, I2
All metal forms fluorides, chlorides, bromides
and iodides.
Einstein Classes,
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New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 3
C3
Characteristics of compound of alkali metal :
(i)
The increasing stability of the peroxide or superoxide as the size of the metal ion increases, is
due to stabilisation of large anions by larger cation through lattice energy effects.
(ii)
All alkali halides are soluble in water. The low solubility of LiF in water is due to its high lattice
enthalpy whereas the low solubility of CsI is due to smaller hydration enthalpy of its two ions.
(iii)
As the electropositive character increases down the group, the stability of the carbonates and
hydrogen carbonates increases.
(iv)
The anomalous behaviour of lithium is due to the small size and high charge/radius ratio.
(v)
Lithium unlike other alkali metals forms no ethynide on reaction with ethyne.
(vi)
The oxides, Li2O and MgO do not combine with excess oxygen to give any superoxide.
(vii)
Both LiCl and MgCl2 are soluble in ethanol.
Compounds of sodium
1.
Sodium Hydroxide (caustic soda) :
Important points :
2.

NaOH finds wide application in paper industry and as a laboratory reagent.

The hydroxides of Na, K, Rb and Cs are very soluble in water, but LiOH is much less soluble.

LiOH is used to absorb carbon dioxide in closed environments such as space capsules (where its
light weight is an advantage in reducing the launching weight).

NaSH is used to remove mercaptans from petroleum products.
Sodium Carbonate :
Important points :

USES
Na2CO3.10H2O
—
washing soda widely used in soap and detergent
Na2CO3.7H2O/
—
crystal carbonate / heavy ash
Na2CO3.H2O
—
widely used in glass manufacturing
Na2CO 3
—
soda ash or light ash earlier used to prepare NaOH, and in
pertoleum refinery and textile industry

Li2CO3 is added as an impurity to Al2O3 to lower its melting point in the extraction of aluminium
by electrolysis. It is used to toughen glass (sodium in the glass is replaced by lithium)

Na2CO3 is not produced by Leblanc process proved non-economical.
Reactions
Preparation
1.
2.

2( Na 2 CO 3 .NaHCO 3 .2H 2 O) 

1.
Na2CO3.10H2O
(Trona or sodium sesquicarbonate)
2.
Na2CO3 is thermally stable and does not give CO2
Na2CO3 + 10H2O
3Na 2 CO 3  CO 2  5H 2 O
Na2CO3 + H2O + CO2  2NaHCO3
Solvay (ammonia-soda) Process
Na2CO3 + Ca(OH)2  2NaOH +
NH 3  H 2 O  CO 2 
 NH 4 HCO 3
3.
0
C
2 NaHCO3 150

 Na 2 CO 3  H 2 O  CO 2
Einstein Classes,
Aq. solution is alkaline due to hydrolysis.
Na2CO3 + 2H2O
NaCl  NH 4 HCO3 
 NaHCO3  NH 4 Cl
4.
CaCO3
2NaOH + H2CO3
Na2CO3 + NO + NO2  2NaNO2 + CO2
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 4
Preparation
Reactions
1.
Ca(OH)2 + Na2CO3  CaCO3 + 2NaOH
2.
Electrolysis of aq. NaCl
yellow
sodium hypo
phosphite

4S  6 NaOH 

Na 2S2 O3  2 Na 2S  3H 2 O
Anode : 2Cl—  Cl2 + 2e—
Cathode : Na+ + e— 
hypro
( sodium thiosulphate )
Na
2Na + 2H2O  2NaOH + H2
Side reactions may also occur if the
ucts mix
prod-
2NaOH + Cl2  NaCl + NaClO + H2O
or 2OH— + Cl2  2OCl— + H2
X 2  2 NaOH 
 NaX  NaXO  H 2 O
cold
sodium
hypohalite
3X 2  6 NaOH 
 5 NaX  NaXO3  3H 2O
hot
sodium
haloate
and following reaction may also occur at the
anode to a smaller extent :
4OH—  O2 + 2H2O + 4e—
A porous diaphragm of asbestos is used to keep
the H2 and Cl2 (and thus cathode and anode) gases
separated from one other because they react with
explostion if they mix.
3.
phosphine
Na+ + Cl—
NaCl (aq)
*

P4  3NaOH  3H 2 O 

3NaH 2 PO 2  PH 3
Mercury Cathode Cell :
During the electrolysis of brine, Na+ is discharged
at cathode (made of mercury)
Na+ + e—  Na
Na atoms produced are dissolved in mercury
form an amalgam. The amalgam is pumped to a
different compartments and water reacts to form
NaOH.
Na (amalgam) + H2O  NaOH + ½ H2 + Hg
Reactions
FeCl3 NaOH
 Fe(OH)3 
brown ppt .
CrCl3 NaOH
 Cr (OH) 3 
green ppt .
Zn  2 NaOH 
 Na 2 ZnO 2  H 2
sodium zincate
2Al  2 NaOH  2H 2 O 
 2 NaAlO2  3H 2
sodium meta
aluminate
Sn  2 NaOH  H 2O 
 Na 2SnO 3  2H 2
sodium stannate
2B  2 NaOH  2H 2 O 
 2 NaBO 2  3H 2
sodium meta
borate
Amphoteric oxides (as well as
hydroxides) dissolve in NaOH.
Al2O3 + 2NaOH  2NaAlO2 + H2
Al(OH)3 + NaOH  NaAlO2 + 2H2O
ZnO + 2NaOH  Na2ZnO2 + H2O
Zn(OH)2 + 2NaOH  Na2ZnO2 + H2O
(similarly with SnO, PbO)
NaOH
CuSO 4  Cu (OH ) 2 
blue ppt .
ZnCl 2  2 NaOH 
 Zn (OH) 2 NaOH
 Na 2 ZnO 2
white ppt .
However, AgOH and Hg(OH)2 decompose to oxide
on heating.

2AgOH 
 Ag 2O  H 2O

Hg(OH) 2 
 HgO  H 2O
NaOH + H2S  NaSH  Na2S
2NaOH + CO2  Na2CO3 + H2O
2NaOH + SO2  Na2SO3 + H2O
2NaOH + 2NO2  NaNO2 + NaNO3 + H2O
Einstein Classes,
soluble
NaOH
AlCl3  3NaOH 
 Al(OH) 3  NaAlO 2
soluble
white ppt .
NaOH
SnCl 2  2 NaOH 
 Sn (OH) 2  Na 2SnO 2
white ppt .
NaOH + NH4Cl  NH3 + NaCl + H2O
6NaOH + 2[Co(NH3)6]Cl3  12NH3 + Co2O3
+ 3NaCl + 3H2O
NaOH + EtOH  NaOEt + H2O
sodium ethoxide
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 5
3.
Sodium Bicarbonates or Sodium Hydrogen carbonate (baking soda) :
Intermediate compound in the solvay process.
Preparation :
NaCl + NH3 + CO2 + H2  NaHCO3 + NH4Cl
Reactions :
0
1.
C
2 NaHCO3 50
100

 Na 2CO 3  H 2O  CO 2
2.
Amphiprotic species is H+ ion donor (acid) and H+ ion acceptor (base)
HCO3— + H+
HCO3—
H2CO3
H+ + CO32—
Other reactions :
1.
2NaNO3
2NaNO2 + O2
2.
4NaNO3
2Na2O + 5O2 + 2N2
3.

KNO3 + Zn 
KNO2 + ZnO

4.

2[Co(NH3)6]Cl3 + 6NaOH 
12NH3 + Co2O3 + 3NaCl + 3H2O

5.
 Cu2I2 + K2SO4 + I2
2CuSO4 + 4KI 
white ppt.
I2 + KI
KI3
(redish brown)
Exceptions :
1.
Lithium is exceptional in that it does not form a solid bicarbonate, though LiHCO3 can exist in solution.
2.
Only Li forms nitride
Miscellaneous Points :
In NaHCO3 the HCO3— ions are linked into an infinite chain, whilst in KHCO3 a dimeric anion is formed.
C4
Alkaline earth metals :
The properties of Group 2 (Alkaline earth metals) : (i) Density : The densities of alkaline earth metals are
low but greater than alkali metals. The densities decreases from Be to Ca with the increase of atomic
number and then increases from Sr to Ba. (ii) Melting point : Alkaline earth metals have low melting point
but higher than that of the alkali metals. There is no regular trend in melting points as we move from top to
bottom in the group. They have smaller size than alkali metals and have higher melting point than that of
alkali metals. Because they aremore closely packed due to increasing nuclear charge. (iii) Atomic size : The
atomic size of alkaline earth metals are smaller than the corresponding alkali metals. Alkaline earth metals
have a higher nuclear charge and therefore, electrons are attracted more towards the nucleus. On moving
down the group the atomic size increases with the increase in atomic number of the shells and the screening
effect. (iv) Ionization enthalpy : The alkaline earth metals have low ionization enthalpy but higher than the
corresponding members of the alkali metals. However, the ionization enthalpy decreases from top to
bottom in moving down the group. This is because with the increase of atomic number, attraction of
outermost electron from the nucleus goes on decreasing. Alkaline earth metal have low IInd ionization
energy as compare to the alkali metals. (v) The hydration enthalpies of alkaline earth metal in the order of
Be2+ > Mg2+ > Ca2+ > Sr2+ > Ba2+.
C5
Chemical properties of alkaline earth metal :
(i)
Effect of air : Due to air Beryllium forms BeO and Be3N2 whereas magnesium forms MgO and
Mg3N2.
(ii)
Due to halogen : Alkaline earth metal forms compounds as M + X2  MX2 (X = F, Cl, Br, I)
Einstein Classes,
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New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 6
(iii)
Reactivity towards hydrogen : All the elements except beryllium combine with hydrogen upon
heating to form their hydrides MH2.
(iv)
Reaction of a acids : The alkaline earth metal readily react with acids liberating dihydrogen.
M + 2HCl  MCl2 + H2
(v)
Solution in liquid ammonia : M + (x + y) NH3  [M(NH3)x]2+ + 2[e(NH3)y]–
Reactions of Alkaline Earth Metals :
Following table summarises reactions of Group 2. From this, it is evident that as we go down the group,
reactivity increases.
Reaction
Comment
M + 2H2O  M(OH)2 + H2
Be probably reacts with steam, Mg with
hot water, and Ca, Sr and Ba react rapidly
with cold water.
M + 2HCl  MCl2 + H2
All the metals react with acids liberating
H2. With HNO3, Be becomes passive due
to formation of oxide layer.
3M + N2  M3N2
All form nitrides at high temperatures.
M + X2  MX2
All the metals from MX2
(X2 = F2, Cr2, Br2, I2)
M + 2NH3  M(NH2)2+ H2
All the metals form amides at high
temperatures.
2M + O2  2MO
Ba + O2  BaO2
All the metals form normal oxide. Ba also
forms peroxide
M + H2  MH2
Ionic salt-like hydrides formed at high
temperature by Ca, Sr and Ba.
or
Mg + H2O  MgO + H2
Mg forms a protective layer of oxide, so despite its favorable reduction potential, it does not react readily
unless the oxide layer is removed by amalgamating with mercury. In the formation of the oxide film it
resembles aluminium.

Be is amphoteric, as it reacts with acid as well as with base.
Be  2 NaOH  2H 2O 
 Na 2 [Be(OH) 4 ] H 2
sodium beryllate
Mg, Ca, Sr and Ba do not react with NaOH and thus are purely basic.

The metals all dissolve in liquid ammonia as do the alkali metals. Dilute solutions are bright blue in colour
due to the spectrum from the solvated electrons. These solutions decompose very slowly, forming amide
and H2, but the reaction is accelerated by many transition metals and their compounds.
2NH3 + 2e—  2NH2— + H2
Evaporation of the ammonia from solutions of alkali metals yields the metal, but in case of alkaline earth
metals, evaporation of ammonia gives hexammoniates of the metals, which slowly decompose to give
amides :
M(NH3)6  M(NH2)2 + 4NH3 + H2
Concentrated solutions of the metals in ammonia are bronze coloured, due to the formation of metal
clusters.
C6
Characteristics of compounds of the alkaline earth metals :
(i)
The alkaline earth metals burns in oxygen to form the monoxide, MO which, except for BeO,
have rock salt structure.
(ii)
All the oxides except BeO are basic in nature and react with water to form sparingly soluble
hydroxide.
Einstein Classes,
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New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 7
MO + H2O  M(OH)2
(iii)
Except for beryllium halides, all other halides of alkaline earth metals are ionic in nature.
(iv)
The solubility in water decreases from CaSO4 to BaSO4. BeSO4 and MgSO4 are soluble in water.
(v)
Nitrates of alkaline earth metal decomposes to give products as shown in reaction as follows :
2M(NO3)2  2MO + 4NO2 + O2
(vi)
1.
(M = Be, Mg, Ca, Sr, Ba)
The chlorides of both beryclium and aluminium have Cl– bridged chloride structure in vapour
phase. Both the chlorides are soluble in organic solvents and are strong Lewis acids. They are
used as Friedal Craft Catalysts.
Compounds of Alkaline Earth Metals :
Oxides and Hydroxides :

Oxides are formed either by heating the metals in oxygen :
2Be + O2  2BeO
2Ca + O2  2CaO
or by heating their carbonates at high temperatures :

CaCO3 

CaO  CO 2

MgCO3 

MgO  CO 2
The addition of limited amount of water breaks the lump of lime. This process is called slaking of lime.
Some reactions of CaO are
CaO + SiO2  CaSiO3
6CaO + P4O10  2Ca3(PO4)2

The oxides are highly stable due to large ionic crystal lattice energies. The values are so high in the case of
oxides of Be and Mg that these compounds are almost insoluble in water. BeO is amphoteric and other
oxides are basic and yield hydroxides in aq. solution.
MgO + H2O  Mg(OH)2
CaO + H2O  Ca(OH)2

Basic strength of the hydroxide increases going down the group.
Be(OH)2 < Mg(OH)2 < Ca(OH)2 < Sr(OH)2 < Ba(OH)2
BeO is insoluble in H2O but dissolves in acid and alkali and is thus amphoteric.
BeO  2HCl 
 BeCl 2  H 2 O
BeO  2 NaOH 
 Na 2 BeO 2  H 2O
sodium beryllate

MgO is not very reactive, especially if it has been ignited at high temperature, and for this reason it is used
as a refractory. BeO is also used as a refractory.

Solubility of hydroxides increases while going down the group.
Be(OH)2 < Mg(OH)2 < Ca(OH)2 < Sr(OH)2 < Ba(OH)2

Ca(OH)2 is called lime water or slaked lime and Ba(OH)2 is called baryta water, lime water or baryta
turns milky by CO2.
Ca (OH) 2  CO 2 
 CaCO3  H 2O
milky
Ba (OH) 2  CO 2 
 BaCO3  H 2O
milky
Ba(OH)2 gives turbidity (milkyness) even on exhaling breath on it.
Einstein Classes,
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New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 8
Milkyness disappears when excess of CO2 is passed.
CaCO3  H 2 O  CO 2 
 Ca (HCO3 ) 2
excess
Temporary hardness in water is due to dissolve Ca(HCO3)2 and Mg(HCO3)2.
Ca (OH ) 2  Na 2 CO 3 
 CaCO 3  2 NaOH
This reaction was used in earlier days to manufacture NaOH from Ca(OH)2.
2.
Bicarbonates and Carbonates :

The carbonates are all ionic, but due to excessive hydration of Be2+, BeCO3 is unusual because it contains
the hydrated ion [Be(H2O)4]2+.

BeCO3 decomposes at low temperature and is placed in the atmosphere of CO2.
BeCO3  BeO + CO2
Thermal stability increases with increase in atomic weight down the group.
BeCO3 < MgCO3 < CaCO3 < SrCO3 < BaCO3

Ca(HCO3)2 and Mg(HCO3)2 exist in water causing temporary hardness which can be removed by boiling as
insoluble carbonates.

Ca (HCO 3 ) 2 

CaCO 3  H 2 O  CO 2

Mg ( HCO 3 ) 2 

MgCO 3  H 2 O  CO 2

Ca(HCO3)2 and Mg(HCO3)2 are amphoteric thus neutralised by acid as well as base :
Ca (HCO3 ) 2  H 2SO 4 
 CaSO 4  2H 2O  2CO 2
Ca (HCO3 ) 2  Ca (OH) 2 
 2CaCO3  2H 2 O
3.
Sulphates :

The solubility of the sulphates in water decreases down the group.
BeSO 4  MgSO 4  CaSO 4  SrSO 4  BeSO 4
so lub le
sparingly so lub le
inso lub le
High solubilities of BeSO4 and MgSO4 are due to the high enthalpy of hydration of the smaller Be2+ and
Mg2+ ions.

The sulphates decompose into oxides and SO3.

MSO 4 

MO  SO 3
Thermal stability of the sulphates increases going down the group as shown by decomposition
temperatures :
BeSO4
0
500 C
MgSO4
0
845 C
CaSO4
0
1149 C
SrSO4
13740C

MgSO4.7H2O is called Epson salt and is used as mild laxative.

CaSO4.2H2O is called Gypsum. Heating converts it into variety of compounds depending on the temperature.
0
0
0
1
C
C
C
CaSO 4 .2H 2O 150

 CaSO 4 . H 2O 200

 CaSO 4 1100

 CaO  SO3
2
gypsum
anhydride
plaster of Paris
when powdered plaster of Paris, CaSO4 . ½ H2O (or 2CaSO4.H2O) is mixed with stoichiometric amount of
water, it sets into a solid mass CaSO4.2H2O — gypsum. Plaster of Paris finds use
—
for plastering walls
—
for making plaster casts (moulds)
Einstein Classes,
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 9
—
industrial
—
sculptural
—
encasing limbs so that broken bones are set straight.

CaSO4.H2O is called Alabaster — a shiny-like marble and is used to make ornaments.


MSO 4  4C 

MS  4CO 
5.
Halides :

Halides MX2 of alkaline earth metals can be prepared by heating the metals with the halogen acid on either
metal or its carbonate :
M + 2HCl  MCl2 + H2
MCO3 + 2HCl  MCl2+ H2O + CO2

The beryllium halides are covalent, hygroscopic and fumes in air due to hydrolysis.
BeCl2 + 2H2O  Be(OH)2 + 2HCl (fumes)

Anhydrous BeCl2 is polymeric. Vapours exists as monomer BeCl2 and dimer (BeCl2)2.

BeF2 is very soluble in water owing to the high solvation energy of Be in forming [Be(H2O)4]2+. The other
fluorides MF2(M2+ = Mg2+, Ca2+, Sr2+, Ba2+) are all almost insoluble.

The chlorides, bromides and iodides of Mg, Ca, Sr and Ba are ionic and are readily soluble in water.

The halides form hydrates and they are hygroscopic.

CaCl2 is widely used for treating ice on roads, particularly in very cold conuntries when it prevents ice
formation even upto —550C.
Einstein Classes,
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 10
E X E R C I S E (OBJECTIVE)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Which of the following have highest ionisation
energy ?
11.
Which of the following trends followed by alkali
metal in boiling point
(a)
Li
(b)
Na
(a)
chloride > fluoride > bromide > iodide
(c)
K
(d)
Rb
(b)
fluoride > chloride > bromide > iodide
(c)
fluoride < chloride < bromide < iodide
(d)
chloride < fluoride < bromide < iodide
When alkali metal react with water then which gas
is librated ?
12.
The low solubility of LiF in water is due to its
(a)
O2
(b)
H2
(a)
low lattice energy
(c)
H2 O 2
(b)
high lattice energy
(d)
NO gas is liberated
(c)
low hydration energy
(d)
high hydration energy
When Rubidium contact with excess of air it turns
into
13.
Halides of lithium are soluble in
(a)
RbO
(b)
Rb2O
(a)
ethanol
(b)
ethyl acetate
(c)
RbO2
(d)
Rb3O5
(c)
acetone
(d)
all of these
Only alkali metal which form compound with
nitrogen is
(a)
Na
(b)
K
(c)
Li
(d)
Rb
14.
Which of the following is the most powerful
reducing agent ?
(a)
Li
(b)
Na
(c)
K
(d)
Cs
The value of standard electrode potential depends
upon
15.
Which of the following is not correct ?
(a)
Lithium is much harder than the other
alkali metals.
(b)
Lithium is least reactive but the strongest
reducing agent.
(c)
Lithium does not form acetylide on
reaction with ethyne.
(d)
Li2O is much more soluble in water as
compare to other alkali metals.
Which the following is not correct ?
(a)
sublimation
(b)
ionization
(a)
Both lithium and magnesium are harder
(c)
hydration
(d)
all of the above
(b)
The dilute solution of alkali metals are blue but the
colour changes to bronze with increase in
Both lithium and magnesium react slowly
with cold water
(c)
Li2O and MgO combine with excess
oxygen to give peroxide.
(d)
LiCl and MgCl2 both are soluble in
ethanol.
(a)
temperature
(b)
concentration
(c)
both
(d)
none
The bronze-coloured solution are of
(a)
paramagnetic
(b)
diamagnetic
(c)
both
(d)
none
The alkali metals are generally forms_______
compound in nature
16.
17.
Which of the following is not the minerals of lithium
(a)
lepidolite
(b)
epsomite
(c)
spodumene
(d)
amblygonite
Sodium can be extracted by
(a)
polar
(b)
covalent
(a)
electrolysis
(c)
ionic
(d)
none
(b)
downs cell
(c)
castner-kellner cell
(d)
none
The hydroxides which are obtained by the reaction
of the oxides with water are all ________
crystalline solids
18.
Sodium hydroxide can be made by use of
(a)
white
(b)
black
(a)
castner-kellner cell
(c)
orange
(d)
red
(b)
diaphragm cell
(c)
nafion membrane cell
(d)
all of the above
Einstein Classes,
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 11
19.
20.
In the solvay process we can made
(a)
NaOH
(b)
CaCl2
(c)
Na2CO3
(d)
All
Which of the following statement is incorrect ?
(a)
(b)
(c)
(d)
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
The atomic and ionic radii of the
alkaline earth metals are smaller than
those of the alkali metals.
IInd ionization enthalpies of the alkali
earth metal are less as compare to alkali
metal.
Alkaline metal are generally softer than
the alkali metal
The b.p. and m.p. are higher of alkaline
earth metal as compare to alkali metal.
Which of the following alkaline earth metal does
not react with water ?
31.
32.
33.
In the electrolyses of magnesium chloride, libration
occurs by
(a)
magnesium at cathode and chlorine at
anode
(b)
magnesium at anode and chlorine at
cathode
(c)
both magnesium and chlorine at anode
(d)
both magnesium and chlorine at cathode
CaO + P4O10  product. Product might be
(a)
Ca(PO4)2
(b)
Ca2(PO4)2
(c)
Ca3(PO4)2
(d)
Ca4(PO4)2
The formula of slaked lime is
(a)
CaCO3
(b)
CaO
(c)
CaSiO3
(d)
Ca(OH)2
The major composition in portland cement is
(a)
Be
(b)
Mg
(a)
CaO
(b)
SiO2
(c)
Ca
(d)
Sr
(c)
Al2O3
(d)
Fe2O3
34.
(a)
metallic
(b)
ionic
Li does not resemble other alkali metals in
following properties
(c)
covalent
(d)
none of these
(a)
Li2CO3 decomposes into oxides while
other alkali carbonates are thermally
stable
(b)
LiCl is predominantly covalent
(c)
Li3N is stable
(d)
All of above
The bond in BeO is
All of the oxides of alkaline earth metal react with
water except
(a)
BeO
(b)
MgO
(c)
SrO
(d)
BaO
BeX2 molecules exist only in phase of
(a)
gas
(b)
solid
(c)
liquid
(d)
all of these
35.
The solubility of the fluorides of alkaline earth metal
increases with increase in
(a)
anion size
(b)
cation size
(c)
both
(d)
none
Large source of fluorine is
(a)
MgF2
(b)
CaF2
(c)
SrF2
(d)
BaF2
36.
The nitrates of alkaline earth metal after
decomposes give the gas
(a)
N2
(b)
O2
(c)
N2O5
(d)
NO
Alkali metals resemble I B (copper family) in
following respects
(a)
+ 1 valency
(b)
sulphates are water soluble
(c)
oxides are strong base
(d)
oxides are strong acids
Mg and Zn resemble in following properties except
(a)
oxides are amphoteric
(b)
carbonates on heating form metal oxides
(c)
oxides are strong base
(d)
37.
oxides are strong acids
+
Na and Ag+ differ in
(a)
Beryllium does not exhibit co-ordination number
more than
Na2CO3 is thermally stable while Ag2CO3
decomposes into Ag, CO2 and O2
(b)
Ag+ forms complexes, Na+ does not
(a)
2
(b)
3
(c)
NaCl is water soluble, AgCl is insoluble
(c)
4
(d)
5
(d)
All of above
Which of the following is not the ore of magnesium
metal ?
38.
Which salt can be used to identify coloured
cation ?
(a)
langbeinite
(b)
epsomite
(a)
borax
(c)
dolomite
(d)
lepidolite
(b)
microcosmic salt
(c)
both
Einstein Classes,
(d)
none
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 12
39.
40.
Intermediate formed by heating microcosmic salt
and which forms coloured bead with salt is
(a)
NH3
(b)
H3PO3
(c)
NaPO3
(d)
H2 O
(a)
MgSO4.7H2O is not isomorphous with
ZnSO4.7H2O
(b)
II A and II B cations are not precipitated
by H2S in acidic medium
(d)
42.
43.
44.
50.
II A and II B sulphates are water soluble
51.
Which is the major constituent of gun power
(a)
nitre
(b)
sulphur
(c)
charcoal
(d)
chile salt petre
Gas X turns lime water milky. X can be
(a)
CO2
(b)
SO2
(c)
both
(d)
none
When SO2 gas is passed into aqueous Na 2CO 3,
product formed is
(a)
NaHSO4
(b)
Na2SO4
(c)
NaHSO3
(d)
Na2SO3
Portland cement does not contain :
(a)
CaSiO4
(b)
CaSiO3
(c)
Ca3Al2O6
(d)
Ca3PO4
Setting of Plaster of Paris is
(a)
both become passive on reaction with
HNO3 due to formation of oxide layer
(a)
oxidation with atmospheric oxygen
(b)
their chlorides are Lewis acids
(b)
combination with atmospheric CO2
(c)
chlorides exist in polymeric form
(c)
dehydration
(d)
All the above
(d)
hydration to yield another hydrate
Going down to II A group, following properties
decreases
(a)
solubility of sulphates in H2O
(b)
hydration energy
(c)
ionisation energy
(d)
all
52.
53.
Molten sodium chloride conducts electricity due to
the presence of
(a)
free electrons
(b)
ions
(c)
Na atom
(d)
Cl atom
54.
A colourless solid X on heating evolved CO2 and
also gave a white residue, soluble in water. Residue
also gave CO2 when treated with dilute acid. X is
(c)
46.
II A and II B chlorides do not impart
colour in flame
49.
Be and Al resemble in
(a)
45.
48.
II A (alkaline earth metals) and II B (zinc family)
resemble :
(c)
41.
47.
Na2CO3
(b)
Ca(HCO3)2
(d)
CaCO3
NaHCO3
55.
Which of the following mixture is known as
mortar
Mixture of MgCl2 and MgO is called
(a)
Porland cement
(b)
Sorrel’s cement
(c)
double salt
(d)
none
The metal which can be obtained from all the three
ores dolomite, magnesite and carnallite is
(a)
sodium
(b)
potassium
(c)
magnesium
(d)
calcium
A compound which can be used in space vehicles
both to absorb CO2 and liberate O2 is
(a)
NaOH
(b)
Na2O
(c)
Na2O2
(d)
CaO + NaOH
Which is not s-block element ?
(a)
[Ar]4s2 3d10 4p6 5s1
(b)
1s2 2s2 2p1
(a)
slaked lime + water
(c)
1s2 2s1 2p1
(b)
CaCO3 + water
(d)
[Ar] 4s1 4p1
(c)
CaCO3 + sand + water
(d)
slaked lime + sand + water
CO2 gas along with solid (Y) is obtained when
sodium salt (X) is heated. (X) is again obtained when
CO2 gas is passed into aqueous solution of (Y). X
and Y are
56.
57.
Diagonal relationship is for
(a)
Li—Na
(b)
Be—Mg
(c)
Si—C
(d)
B—Si
Maximum size of hydrated ion is
(a)
Li+
(b)
Na+
(c)
K+
(d)
Cs+
(a)
Na2CO3, Na2O
(b)
Na2CO3, NaOH
(c)
NaHCO3, Na2CO3
(a)
Li
(b)
Na
(d)
Na2CO3, NaHCO3
(c)
both
(d)
none
Einstein Classes,
58.
Nitrate is converted into metal oxide on heating.
This metal is
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 13
59.
60.
61.
62.
63.
64.
There is loss in weight when mixture of Li2CO3 and
Na2CO3.10H2O is heated strongly. This loss is due
to
Li2CO3
(b)
Na2CO3.10H2O
(a)
cations are coloured ions
(c)
both
(d)
none
(b)
anions are coloured ions
(c)
both correct
(d)
none is correct
Which disproportionates into M2O2 (peroxide) and
M (metal) ?
(a)
Li2O
(b)
Na2O
(c)
both
(d)
none
(a)
NaOH, Na2O, Li2O
Which is main constituent of egg-shell ?
(b)
Na2O, Li2O
(a)
CaCO3
(b)
CaSiO3
(c)
Na2O, Li2O, Li3N, NH3
(c)
CaSO4.½H2O
(d)
CaSO4.2H2O
(d)
Na2O, Li3N, Li2O
The deliquescent among the following is
68.
69.
Na and Li are placed in dry air. We get
Alkali metals form following compounds
(a)
CaCl2
(b)
FeSO4.7H2O
(a)
all form amide, MNH2
(c)
CuSO4.5H2O
(d)
BaCl2.2H2O
(b)
potassium form superoxide like, KO2
(c)
all form ionic ‘salt-like’ hydride MH
(d)
all the above
Alkali metals dissolve in liquid NH3, then which of
the following observations are true ?
(a)
H2 gas is liberated
(b)
solution is blue due to the presence of
solvated electrons
(c)
solution is conducting
(d)
all the above
Which is false statement ?
the heats of hydration of the dipositive
alkaline earth metal ions decrease with
an increase in their ionic size.
70.
71.
72.
Which of the following is the best CO2 absorber as
well as source of O2 in submarines
(a)
KO2
(b)
K2O 2
(c)
KOH
(d)
LiOH
Which is paramagnetic :
(a)
KO2
(b)
O2
(c)
NO2
(d)
All
Baking powder contains :
(b)
hydration of alkali metal ion is less than
that of II A.
(a)
NaHCO3,Ca(H2PO2)2 and starch
(b)
NaHCO3,Ca(H2PO2)2
(c)
alkaline earth metal ions, because of their
much larger charge to size ratio exert
a much longer electrostatic attraction on
the oxygen of water molecule
surrounding them.
(c)
NaHCO3, starch
(d)
NaHCO3
(d)
66.
Some of alkali metal salts are coloured
Na 2CrO4— yellow, KMnO4— pink, K 2MnO 4 —
green. It is due to
(a)
(a)
65.
67.
73.
none of the statements is correct
Which is/are true statement(s) about s-block
elements ?
(a)
metals are obtained by the electrolysis of
fused chlorides
(b)
only one type of valency, + 1 for IA and
+ 2 for IIA,is shown
(c)
all are metals
(d)
all the above
74.
75.
Following compounds are used in fire-works :
(a)
LiNO3
(b)
BaCl2
(c)
(NH4)2Cr2O7
(d)
All
When NO is passed into KOH solution, products
are
(a)
N2
(b)
N 2O
(c)
both
(d)
none
Which has least molar solubility in H2O
(a)
LiCl
(b)
NaCl
(c)
KCl
(d)
CsCl
Which is most stable halide of alkali metal
(a)
sodium fluoride
(b)
sodium bromide
(c)
sodium chloride
(d)
sodium iodide
Einstein Classes,
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 14
NOTE : Q.76 to 78 are based on following
reaction(s)
83.

A

B(oxide)  CO 2
B  H 2O 
 C
84.
C  CO 2 
 A(milky)

C  NH 4 Cl 

D(gas)
D  H 2 O  CO 2 
 E
E  NaCl 
 F

F

Na 2CO 3  CO 2  H 2 O
76.
77.
78.
79.
80.
85.
Name of the process is
(a)
Solvay
(b)
ammonia-soda
(c)
both correct
(d)
none is correct
(a)
Ca(HCO3)2
(b)
CaCO3
(c)
CaO
(d)
Na2CO3
86.
A is
B and C are
87.
(a)
CaO, Ca(OH)2
(b)
Ca(OH)2, CaCO3
(c)
CaCO3, Ca(OH)2
(d)
Ca(OH)2, CaO
88.
D, E and F are
(a)
NH3, NH4Cl, NH4HCO3
(b)
NH3, NH4HCO3, NaHCO3
(c)
NH4HCO3, Na2CO3, NaHCO3
(d)
none
89.
Following are the ionisation potential values of :
(I1) 899 kJ mol–1, (I2) 1757 kJ mol–1
(I3) 15000 kJ mol–1
81.
82.
(a)
Na
(b)
K
(c)
Be
(d)
Ne
90.
Which is most stable out of the following
(a)
[Be(H2O)4]2+
(b)
[Mg(H2O)4]2+
(c)
[Ca(H2O)4]2+
(d)
[Sr(H2O)4]2+
Lattice energy of II A group compounds
(oxides, carbonates, fluorides)
(a)
decreases as size of the ion increases
(b)
increases as size of the ion increases
(c)
constant for a given type of anion
(d)
all incorrect
Einstein Classes,
91.
92.
Which of the following statements are true about
II A group elements ?
(a)
all form nitrides in air
(b)
Be is amphoteric
(c)
MH2 is ionic ‘salt-like’ hydride
(d)
all the above
In water :
(a)
temporary hardness is due to the
bicarbonates of Ca2+ and Mg2+
(b)
permanent hardness is due to chlorides
and sulphates of Ca2+ and Mg2+
(c)
hardness can be removed by adding
phosphates
(d)
all the above
Na2[Be(OH)4] is formed when
(a)
BeO reacts with NaOH solution
(b)
Be reacts with NaOH solution
(c)
both correct
(d)
none is correct
Noble gases (like He, Ne, Ar, Kr, etc.) are isolated
from air. One of the step(s) is/are
(a)
heating air with Li or Mg
(b)
bubbling air into NaOH solution
(c)
both correct
(d)
none is correct
Which is used to treat acid indigestion ?
(a)
Be(OH)2
(b)
KOH
(c)
Mg(OH)2
(d)
Ca(OH)2
Which is true statement when metal carbides react
with H2O ?
(a)
Al4C3 + H2O  CH4
(b)
CaC2 + H2O  CH  CH
(c)
Mg4C3 + H2O  CH3C  CH
(d)
all of above
Select correct statement :
(a)
Beryllium and magnesium hydride are
covalent and polymeric
(b)
CaH2, SrH2 and BaH2 are ionic
(c)
BeH2 contains three-centre two-electron
H2
(d)
all of above
Out of AgF, CaF2, BeF2, MgF2
(a)
AgF and BeF2 are soluble and CaF2 and
MgF2 are insoluble in water
(b)
AgF is soluble others insoluble
(c)
CaF2, BeF2, MgF2 soluble, AgF insoluble
(d)
all insoluble
Which is used for fixing atmospheric nitrogen ?
(a)
CaCN2 (nitrolim)(b)
Li3N
(c)
Mg3N2
(d)
all
Molecular formula of Glauber’s salt is
(a)
MgSO4 · 7H2O
(b)
CuSO4 · 5H2O
(c)
FeSO4 · 7H2O
(d)
Na2SO4 · 10H2O
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 15
93.
94.
95.
96.
97.
98.
99.
100.
101.
102.
A solution of sodium sulphate in water is
electrolysed using inert electrodes. The products at
the cathode and anode are respectively
(a)
H2, O2
(b)
O2, H2
(c)
O2, Na
(d)
O2, SO2
The metallic lustre exhibited by sodium is explained
by
(a)
diffusion of sodium ions
(b)
oscillation of loose electron
(c)
excitation of free protons
(d)
existence of body centred cubic lattice
The oxidation states of the most electronegative
element in the products of the reaction, BaO2 with
dil. H2SO4 are
(a)
0 and –1
(b)
–1 and –2
(c)
–2 and 0
(d)
–2 and –1
The following compounds have been arranged in
order of their increasing thermal stabilities.
Identify the correct order :
K2CO3(I), MgCO3(II), CaCO3(III), BeCO3(IV)
(a)
I < II < III < IV (b)
IV < II < III < I
(c)
IV < II < I < III (d)
II < IV < III < I
Which of the following statements is correct for
CsBr3 ?
(a)
It is covalent compound
(b)
It containes Cs3+ and Br– ions
(c)
It contains Cs+ and Br3– ions
(d)
It contains Cs+, Br– and lattice Br2
molecule
KF combines with HF to form KHF 2 . The
compound contains the species :
(a)
K+, F–, and H+ (b)
K+, F– and HF
+
–
(c)
K and [HF2]
(d)
[KHF]+ and F–
Sodium thiosulphate is prepared by :
(a)
reducing Na2SO4 solution with H2S
(b)
boiling Na2SO3 solution with S in
alkaline medium
(c)
neutralising H2S2O solution with NaOH
(d)
boiling Na2SO3 solution with S in acidic
medium
A dilute aqueous solution of Na2SO4 is electrolysed
using platinum electrodes. The products at the
anode and cathode are
(a)
O2, H2
(b)
S2O82–, Na
(c)
O2, Na
(d)
S2O82–, H2
MgSO4 on reaction with NH4OH and Na 2HPO4
forms a white crystalline precipitate. What is its
formula ?
(a)
Mg(NH4)PO4
(b)
Mg3(PO4)2
(c)
MgCl2 · MgSO4 (d)
MgSO4
Arrange the following sulphates of alkaline earth
metals in order of decreasing thermal stability :
BeSO4, MgSO4, CaSO4, SrSO4
(a)
SrSO4 > CaSO4 > MgSO4 > BeSO4
(b)
SrSO4 < CaSO4 < MgSO4 < BeSO4
(c)
SrSO4 > CaSO4 > MgSO4 < BeSO4
(d)
SrSO4 > CaSO4 < MgSO4 > BeSO4
Einstein Classes,
103.
Identify (X) in the following synthetic scheme and
write their structures.
*
Ba C O 2  H 2SO 4  X(gas) (C* denotes C14)
*
(a)
C O2
(b)
CO2
(c)
SO2
(d)
SO3
A N S W E R S (OBJECTIVE)
1.
a
27.
b
53.
c
79.
b
2.
b
28.
c
54.
c
80.
c
3.
c
29.
d
55.
b
81.
a
4.
c
30.
a
56.
d
82.
a
5.
a
31.
c
57.
a
83.
d
6.
d
32.
d
58.
a
84.
d
7.
b
33.
a
59.
c
85.
c
8.
b
34.
d
60.
b
86.
c
9.
c
35.
a
61.
a
87.
c
10.
a
36.
a
62.
a
88.
d
11.
b
37.
d
63.
d
89.
d
12.
b
38.
c
64.
d
90.
a
13.
b
39.
c
65.
d
91.
a
14.
d
40.
b
66.
a
92.
d
15.
c
41.
d
67.
b
93.
a
16.
b
42.
d
68.
d
94.
d
17.
b
43.
b
69.
d
95.
b
18.
d
44.
d
70.
a
96.
b
19.
c
45.
d
71.
d
97.
c
20.
c
46.
c
72.
a
98.
c
21.
a
47.
c
73.
d
99.
b
22.
c
48.
c
74.
c
100.
a
23.
a
49.
d
75.
c
101.
a
24.
a
50.
d
76.
c
102.
a
25.
b
51.
d
77.
b
103.
a
26.
b
52.
b
78.
a
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
CSB – 16
TEST YOURSELF
1.
2.
3.
4.
5.
6.
7.
Which is not correct configuration of s-block
elements ?
Lattice energy (numerical value) of chloride of
alkali metals is in order
(a)
[He]2s1
(b)
[Ar]3d104s1
(a)
LiCl > NaCl > KCl > RbCl > CsCl
(c)
[Ar]4s2
(d)
[Ar]4s1
(b)
LiCl < NaCl < KCl < RbCl < CsCl
(c)
NaCl < KCl < LiCl < RbCl < CsCl
(d)
NaCl < KCl < RbCl < CsCl < LiCl
Be and Al show diagonal relationship hence both
have
10.
Which does not exist in solid state
(a)
same degree of electronegativity
(b)
amphoteric nature of oxides
(a)
NaHCO3
(b)
NaHSO3
(c)
approximately same charge/radius ratio
(c)
LiHCO3
(d)
CaCO3
(d)
All the above
Which of the following is preferentially formed on
reaction of oxygen and potassium ?
(a)
K2 O 2
(b)
KO2
(c)
K2 O
(d)
K2 O 3
Function of lime stone in the manufacture of iron
from haematite is
(a)
as a slag
(b)
as a flux
(c)
as a reducing agent
(d)
as a gangue
Magnesium oxide cannot be obtained by heating
(a)
MgCO3
(b)
Mg(NO3)2
(c)
Mg(OH)2
(d)
MgSO4
Identify the correct statement
(a)
Gypsum is obtained by heating Plaster
of Paris
(b)
Plaster of Paris can be obtained by
hydration of gypsum
(c)
Plaster of Paris contains higher
percentage of calcium than does gypsum
(d)
Plaster of Paris is obtained from gypsum
by oxidation
Choose the incorrect alternate
(a)
BeCO3 is kept in the atmosphere of CO2
since it is least thermally stable.
(b)
Be dissolves in alkali forming
Be(OH)4)]2—
(c)
BeF2 farms complex ion with NaF in
which Be goes with cation
(d)
8.
9.
BeF2 farms complex ion with NaF in
which Be goes with anion
Which can not be used to generate H2 ?
(a)
Al + NaOH
(b)
Zn + NaOH
(c)
Mg + NaOH
(d)
LiH + H2O
Einstein Classes,
ANSWERS
1.
b
6.
c
2.
d
7.
c
3.
b
8.
c
4.
b
9.
a
5.
d
10.
c
Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111