S BLOCK Flashcards
1
Q
1st Grp. elements(Alkali Metals)
A
lithium , sodium , potassium, rubidium, caesium and francium
2
Q
2nd Grp. elements(Alkaline earth metals)
A
beryllium, magnesium, calcium, strontium, barium, radium
3
Q
Half life time of francium
A
21 minutes(longest lived isotope) and radioactive
4
Q
where are alkaline earth metals found
A
earth crust as meta oxides
5
Q
where do calcium and magnesium rank in abundance
A
6
Q
where is radium found
A
igneous rocks
7
Q
E.C of alkali metals
A
[noble gas] ns1
8
Q
E.C of alkaline earth metals
A
[noble gas] ns2
9
Q
which 2 pairs are in diagonal relationship
A
lithium and magnesium ; beryllium and aluminium
10
Q
diagonal relationship arises due to
A
similar ionic sizes or charge/mass ratio
11
Q
elements present in bio fluids to maintain ion balance and treat nerve disorders
A
sodium, potassium, calcium and magnesium
12
Q
ion formed by first grp. elements
A
M+ (most electropositive)
13
Q
which grp. elements are most electropositive
A
1st
14
Q
which grp. elements have largest sizes
A
1st
15
Q
general value of I.E for 1st grp. elements
A
low
16
Q
trend of atomic radius in grp.1
A
increases top t bottom
17
Q
trend of I.E in grp.1
A
decreases down the grp.(incr. size outweighs the nuclear charge)
18
Q
trend of hydration enthalpies in grp. 1
A
decreases top to bottom
19
Q
physical appearance of grp.1 elements
A
silvery white , soft and light
20
Q
general value of density in grp.1
A
low
21
Q
trend of density with exception
A
increases down the group but potassium lighter than sodium
22
Q
general value of M.P and B.P of grp.1
A
low due to weak metallic bonding
23
Q
Photoelectric color of li
A
crimson red
24
Q
Photoelectric color of na
A
yellow
25
Photoelectric color of k
violet
26
Photoelectric color of rb
red violet
27
Photoelectric color of cs
blue
28
how can alkali metals be detected
flame tests
29
elements used as electrodes in grp.1
caesium and potassium
30
reactivity of alkali metals
high due to large size and low I.e
31
alkali metals + air
burn vigorously in oxygen to tarnish by producing oxides
32
monoxide is formed by which alkali metal
lithium
33
peroxide is formed by which alkali metal
sodium
34
oxides formed by k,rb,cs
superoxide
35
O.S of alakli metals
+1
36
li+n
li3n is formed by li exceptional reactivity
37
where are alkali metals stored due to high reactivity towards water
kerosene
38
alkali metals+ water
hydroxide with h2
39
which alkali metal has the most e- value
lithium
40
which alkali metal has the least e- value
sodium
41
which alkali metal is an exception to their explosive reaction to water
lithium due to very low size
42
alkali metals+h2 9673k)
hydrides (M+H-)
43
alkali metals with halogens
ionic halides (M+X-)
44
which is the only alkali metal that forms a covalent halide
lithium
45
which lithium halide is most covalent
lithium iodide
46
nature if alkali metals in redox rxns.
reducing agents
47
most powerful r.a alkali metal
lithium due to high hydration enthaly
48
least powerful r.a alkali metal
sodium
49
relation between standard reduction potential and r.a
inversely proportional
50
alkali metals + liq. nh3 solns.
alkali metals dissolve and turn it into blue color due to ammoniated e-
51
magnetic nature of alkali metal + ammonia soln.
paramagnetic
52
ammoniated e-+M+
amide + h2
53
in conc. ammonia soln. blue color and paramagnetic changes to
bronze color and diamagnetic
54
use of li
with mg to make armor plates
with al to make aircraft parts
with pb to make bearings for motor engines
thermonuclear rxns.
electrochemical cells
55
use of na
with na to make anti knock additives to petrol
liq. coolant in nuclear rxns.
56
use of potassium
bio fluid
fertilizer
soft soap(KOH)
absorbent of CO
57
use of cs
devising photoelectric cells
58
li+air
li2o mostly and some li2o2
59
na+air
na2o2 mostly and some nao2
60
trend if stability of oxides
increases with incr. in metal ion sizes
61
alkali metal oxides+water
hydroxides
62
color of oxides and peroxides
colorless
63
color of super oxides
yellow and orange
64
magnetic nature of superoxides
paramagnetic
65
widely used alkali metal oxide as o.a
sodium peroxide
66
alkali metal hydroxides appearance
white crystalline solids
67
most strong bases
alkali metal hydroxides
68
physical nature alkali metal halides
high MP and colorless crystalline solids
69
HX+ appropriate oxide/hydroxide/carbonate
alkali metal halides
70
trend of formation enthalpy of alkali metal halides
high negative down the grp. except fluorine
71
trend of formation of alkali metal halides
less negative from MF to MI
72
trend of MP of halides
decreases don the grp.
73
solubility of alkali metal halides in water
high except LiF(very low) and CsI(very high)
74
licl is soluble in which organic compound
pyridine
75
carbonates of metal oxo acids
metal bicarbonates most likely and metal carbonates too
76
nature of alklai metal oxo acids
thermally stable soluble i water
77
alkali metals + oxo acids
salts
78
trend of stability of alakli metal carbonates
increases down the grp.
79
which alkali metal carbonate is unstable to heating
li
80
reasons for anamolous behaviour of li
very small size
high polarizing power which gives rise to high covalent characters
81
anamolous properties of li
hardest
high MP and BP
;east reactive but strongest r.a
mainly forms li2o and li3n with air
deliquescent
crystallizes as hydrates
lithium HCs aren't available as solids
doesn't form ethynide with ethyne
lithium nitrate(li3n) heated to give li2o but generally nitrites are formed
lif and li2o are comparitively less water soluble
82
reason for diagonal relationship with mg
similar sizes
83
diagonal similarities between li and mg
harder and lighter
slow rxn. with water
less stable and soluble oxides and hydroxides
nitrates
nitrates heated to give oxides instead of nitrogen
oxides don't give superoxides
carbonates are decomposed easily on heating to from oxides and co2
halides are soluble in ethane
halides are deliquescent and crystallize to form aq. solns. as hydrates
84
industrial name of sodium carbonate(na2co3.10h20)
washing soda
85
washing soda is prepared by what process
solvay orocess
86
advantage of sodium hydrogen carbonate that promotes it to undergo solvay process
less solubility
86
by product of solvay process
calcium chloride
87
reactants of solvay process
ammonium carbonate, nacl, co2
88
appearance of washing soda
white crystalline solid
89
solubility in water
readily soluble
90
type of hydrate formed on heating washing soda
monohydrate
91
monohydrate of washing soda above 373 K
white powder called soda ash
92
carbonate prt of washing soda + h2o
alkaline soln.
93
uses of washing soda
softening, laundering, cleaning
manufacture of glass, borax, soap, caustic soda
paper, paint and textile industry
lab reagent in qualitative and quantitative analysis
94
most abundant source of nacl
sea water
95
how is salt produced in india
evaporating sea water
96
salt produced in india every year
50 lakh tons
97
impurities in brine
caso4, na2so4, cacl2, mgcl2
98
reactants in prep. of nacl
crude nacl, water, hcl (gas)
99
use of nacl
table or common salt
prep of na2o, naoh, na2co3
100
industrial name of naoh
caustic soda
101
process of prep. of caustic soda
elctrolysis
102
reactants used in the prep of naoh
brine soln., mercury cathode, carbon anode
103
what is produced at cathode in naoh prep.
sodium amalgam(nahg)
104
what is obtained at anode in naoh prep.
cl2 gas
105
from which initial product do we get naoh
sodium amalgam
106
appearance of naoh
white, translucent solid, deliquescent
107
MP of naoh
591K
108
MP of nacl
1081K
109
nature of naoh
strongly alkaline
110
naoh+co2
na2co3
111
uses of naoh
manufacture of soap paper, artifical silk
petroleum refining
purification of bauxite
mercerising cotton
prep. of pure fats and oil
lab reagent
112
industrial name of sodium hydrogen carbonate(nahco3)
baking soda
113
use of sodium bicarbonate
mild antiseptic for skin infections
fire extinguishers
114
reactants used in prep. of baking soda
na2co3, h2o, co2
115
most abundant metal in our body
potassium
116
where are na cells found inside our body
outside the cells in interstitial fluids like blood plasma
117
use of na in our body
messengers
transport sugar and amino acids
controls flow of water across cell membrane
118
use of potaasium in our body
enzyme activator
oxidizes glucose
mesenger
119
pump that operates across cell membranes
na-k pump
120
energy consumed by na-k pump
1/3rd ATP in resting animal
15Kg in a day in resting human
121
relation between size of grp. 2 and grp.1 elements
grp.2 < grp.1 due to incr. in nuclear charge
122
trend of atomic radius in grp.2
incr. down the grp.
123
general value of IE in grp.2 elements
low
124
trend of IE in grp.2
decreases down the gr.
125
relation between IE1 of grp. 2 and grp.1 elements
grp.1 < grp. 2
126
relation between IE2 of grp. 2 and grp.1 elements
grp.1 > grp. 2
127
trend of hydration enthalpies in grp. 2
decreases down the grp.
128
relation between hydration enthalpies of grp. 2 and grp.1 elements
grp. 2 > grp.1
129
appearance of alkaline earth metals
slivery white, lustrous and relatively soft but harder than alkali metals
130
relation between MP and BP of grp. 2 and grp.1 elements
grp. 2 > grp. 1
131
trend of electropositive character in grp.2 elements
incr. down the grp.
132
calcium color to flame
brick red
133
strontium color to flame
crimson
134
barium color to flame
apple green
135
alkaline earth metals that don't release color on de excitation
be and mg
136
flame test for which alkaline earth metals is helpful in qualitative and quantitative estimation
ca, sr, ba
137
alkaline earth metals conductivity vaue generally
high
138
reactivity of alkaline earth metals
less than alkali metals
139
alkaline earth metals which are chemically inert to water due to formation of oxide film
be and mg
140
be and mg when burnt in air
mo and m3n2
141
ca, ba, strontium + air
oxide, nitride and also hydroxides
142
alkaline earth metals + x2
MX2
143
convenient way to make bef2
thermal decomposition of (nh4)2bef4
144
becl2 is prep. from
beo
145
alkaline earth metals + h2
metal hydrides
146
condition for formation of beh2
becl2+lialh4
147
alkaline earth metals + acids
h2 is liberated
148
nature of grp. 2 elements in redox rxns.
r.a
149
grp. 2 element with least r.a tendency
beryllium
150
relation between reducing power of grp.1 and grp. 2
grp.1 > grp.2
151
alkaline earth metals + liq. nh3 solns.
deep blue black solns. with ammoniated ions
152
uses of be
cu-be alloys in high strength springs
windows of x ray tubes
153
uses of mg
mg-al alloy in aircraft making
flash powders, bulbs, incedinary bombs
milk of magnesia as antacids
mgco3 as toothpastes
154
uses of ca
extradition of metals from oxides
155
which 2 alkaline earth metals are combined used for removing air from vaccum
ca and ba
156
use of radium
radiotherapy like to treat cancer
157
O>S of grp.2 elements
2
158
nature of grp.2 elements compounds
ionic but less than alkali metals
159
nature of beo and mgo
covalent
160
structure of alkaline earth metals oxide and hydroxide
rock salt except beo
161
nature of alkaline earth metal oxides
ionic and basic except beo (covalent and amphoteric)
162
trend of solubility , stability and basic character of A.E.Ms
incr. down the grp. but less than alkali metals
163
nature of A.E.M halides
ionic except beo(covalent)
164
structure of beo
chain which forms chloro-bridged dimer that dissociates into linear one at high temperatures
165
Trend of Halide formation in grp.2
decreases down the grp.
166
way to dehydrate grp.2 elements
heat them(except be and mg - hydrolysis on heating)
167
stability between grp.2 fluorides and chlorides
f < cl
168
Water solubility of grp. 2 carbonates
insoluble
169
Trend of Water solubility of grp. 2 carbonates
decreases down the grp.
170
where only can beo be kept
atmosphere of co2
171
Trend of Thermal stability in grp.2
incr. down the grp.
172
Trend of Water solubility of grp. 2 sulphates
decr. down the grp.
173
Appearance of grp. 2 sulphates
white solids
174
Water of crystallization of mg3n2 and be3n2
6 and 0
175
grp. 2 nitrates on decomposition give
oxides
176
anamolous properties of be
largely covalent
easily hydrolysed
maximum CN=4
oxide and hydroxide are amphoteric
177
reason for anamolous properties of be
very small size
178
reason for diagonal relationship between be and al
same size and similar charge to mass ratio
179
diagonal similarities between be and al
not readily attacked by acids
dissolve in water to give beryllate and aluminate ion
chlorides are ridged in vapor phase and strong L.A
string tendency to form complexes
180
calcium oxide is also called as
quick lime(CaO)
181
prep. of cao
limestone heating
182
appearance of cao
white amorphous solid
183
MP of cao
2870K
184
addition of limited amount of water to break lump of cao is called
slaking of lime
185
quick lime slaked with soda lime gies
solid sodalime
186
uses of cao
manufacturing cement, na2co3 from naoh and dye stuffs
purification of sugar
187
cheapest from of alkali
cao
188
ca(oh)2 is also known as
slaked lime(CaCO3)
189
prep. of slaked lime
cao=water
190
appearance of slaked lime
white amorphous powder
191
Water solubility of slaked lime
very less
192
aq. slaked lime is called
lime water
193
slaked lime in water is called
milk of lime
194
co2 + saked lime
milky due to caco3 formation
195
caco3+h2o
calcium bicarbonate
196
milk of lime + cl2
hypochlorite (a bleaching powder constituent)
197
uses of ca(oh)2
prep. of mortar
white wash
disinfectant
tanning industry
prep. of bleaching powder and glass
purification of water
198
caco3 exists in nature as
limestone, marble
199
prep. of caco3
slaked lime + co2
(or)
na2co3 + cacl2
200
appearance of caco3
white fluffy powder
201
Solubility of caco3 in water
insoluble
202
caco3 decomposes on heating to from
cao + cp2
203
caco3 + dilute acid
liberates co2
204
uses of caco3
manufacture of cao
building material
marble
along with mgco3 used in metal extraction
manufacture of high quality
paper
antacid
toothpaste
contituent of chewing gum
filler in cosmetics
205
calcium sulphate is also called
plaster of paris (pop) (caso4.1/2 h2o)
206
pop is decrystallized at and to
above 393 K to caso4 (dead burnt plaster)
207
time taken to form plastic plate with pop in water
5 - 15 minutes
208
uses of pop
building industry
setting up fractures and sprains
dentistry
ornamental works
getting casts and moulds
209
cement was introduced by
Joseph Aspidin(1824)
210
what was the other name of first introduced salt
Portland cement
211
composition of cement
cao - 50 to 60 %
sio2 - 20 to 25%
al2o3 - 5 to 10%
mgo - 2 to 3%
so3- 1 to 2%
212
ratio of silica and alumina for good cement
2.5:4
213
ratio of lime to silicon, aluminium, iron oxides
2
214
raw material for cement
limestone and clay
215
prep. of cement
limestone and clay - cement clinker + 2 to 3% gypsum(caso4.2 h2o)
216
important ingredients of portland cement
dicalcium silicate and tricalcium silicate and aluminate
217
hydration of molecules of constituents and their rearrangement to give hard mass of cement
setting of cement
218
what is added to slow down the process of setting of cement
gypsum
219
uses of cement
concrete manufacture and reinforcement
plastering
construction of bridges, dams
220
amount of grp.2 elements in our body
mg - 25g
Ca - 1200g
221
uses of mg and ca in our body
mg acts as cofactor to enzymes that utilize atp
chlorophyll has mg
99% body ca is in bones and teeth
ca is neuromuscular messenger
ca concentration in blood plasma is around 100 mg/L maintained by 2 hormones calcitonin and parathyroid
