THE S-BLOCK ELEMENTS Quiz-11

Chemistry Aptitude Quiz

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IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies. Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..

Q1. The commonn name, “cream of tartar” refers to

•   KHC4H4O6
•   LK(SbO)C4H4O6
•  KNaC4H4O6
•  Mg(OH)2(C4H4O6)H2O

Solution
(b) part
Potassium antimonyl tartrate

Q2.The alkalide ion is

•   Diamagnetic
•  Represented as ¯CH3
•   Paramagnetic
•  Represented as CH3

Solution
(a) part
(a) Na^+ is alkalide ion
Na(1s^2 2s^2 2p^6 4s^1)← Paramagnetic due to unpaired electrons
Na^- (1s^2 2s^2 2p^6 3s^2)← Diamagnetic due to paired electrons

Q3.   Which is the most stable halide of alkali metal?

•   Sodium fluoride
•  Sodium bromide
•  Sodium chloride
•  Sodium iodide

Solution
(a) part

Q4. Choose the incorrect statement

•   BeCO_3 is kept in the atmosphere of CO_2 since it is least thermally stable
•   BeF_2 forms complex ion with NaF in which Be goes with anion
•   Be dissolves in alkali forming [Be(OH)4]^(2-)
•   BeF_2 forms complex ion with NaF in when Be goes with cation

Solution
(d)
2NaF+BeF2 → Na2[BeF4] ⇌ 2Na^(+) + [BeF4]^(2-) anion

Q5.Some of alkali metal salts are coloured. Na2CrO4-yellow, KMnO4-pink, K2MnO4-green. It is due to

•   Cations are coloured ions
•   Anions are coloured ions
•  All of the above
•   None of the above

Solution
  (b) part
Alkali salts are colourless
NaCl colourless Na2CrO4-yellow since CrO4^(3-) is yellow
KCl colourless K2CrO4- yellow
KMnO4- pink since MnO4^- is pink
K2MnO4- green since MnO4^(2-) is green

Q6.  When NO is passed into KOH solution, products are

•   K20 ,NO2
•  K2O, K2O2
• K20, NO2
•  NO2 , N2O2

Solution
(a) PART
KO2 (O2^- is paramagnetic due to one unpaired electron) NO2 (is paramagnetic due to one unpaired electron on N)

Q7. Following are the ionization potential values of
(I_1 )899 kJ mol^(-1)
(I_2 )1757 kJ mol^(-1)
(I_3 )15000 kJ mol^(-1)

•   Na
•  K
•   Be
•   Ne

Solution
(c)
(IE)_3 is very high indicates +2 oxidation state. Thus, Be

Q8.

Which is the incorrect statement?

•  The heats of hydration of the dipositive alkaline earth metal ions decrease with an increase in their ionic size
•  NaNO3 forms Na2O on heating
•  Hydration of alkali metal ion is less than that of II A
•  Alkaline earth metal ions, because of their much larger charge to size ratio, exert a much stronger electrostatic attraction on the oxygen of water molecule surrounding them

Solution
(b) part
2NaNO3 → 2NaNO2 + O2

Q9.A basic refractory material among the following is

•   Al2O3
•   SiO2
•   Fe2O3
•   CaO

Solution
(d) part

Q10. Which has least molar solubility in H2O?

•  LiCl
•  NaCl
•   KCl
• CsCl

Solution
(C) part
Molar solubility is in mol L^(-1) (Reference Concise) inorganic Chemistry J.D. Lee)
LiCl=19.6
NaCl=6.2
KCl=4.8
RbCl=7.5
CsCl=11.0