THE P-BLOCK ELEMENTS-11th Quiz-14

CHEMISTRY THE P-BLOCK ELEMENTS-11th
QUIZ-14

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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.Calcium cyanamide on treatment with steam produces

• NH₃ + CaO
• NH₃ + CaHCO₃
• NH₃ + CaCO₃
• NH₃ + Ca(OH)₂

Solution
CaCN₂ + 3H₂O → CaCO₃ - 2NH₃

Q2.Pure boron is best prepared by

•  Heating B₂O₃ with H₂
•  Heating B₂O₃ with Na or K
•  Heating KBF₄ with Na or K
•  Heating BBr₃ with H₂ in the presence of a catalyst

Solution
Heating B₂O₃ with Na or K

Q3.While testing BO₃^3-, there is green-edged flame on heating the salt with conc. H₂SO₄ and CH₃OH. Green colour is of

•  (CH₃)₃B
•  (CH₃O)₃B
•  B₂O₃
•  H₃BO₃

Solution
BO₃^3- + H₂SO₄ → H₃BO₃
H₃BO₃ + 3CH₃OH → (CH₃O)₃B + H₂O
(CH₃O)₃B is of green colour

Q4.The compound having maximum carbon percentage is

•  Peat
•  Bituminous
•  Lignite
•  Anthracite

Solution
Anthracite.
Carbon percentage in compounds are as:
Peat - less than 60%
Lignite - 60-70%
Bituminous- 77-87%
Anthracite - over 87%

Q5.The statement true for N₃^- is

•  It has non-linear structure
•  It is called pseudohalogen
•  The formal oxidation state of nitrogen in this anion is +1
•  It is isoelectronic with N₂O

Solution
N₂O : 14 + 8 = 22
N₃^- : 21 + 1 = 22

Q6.Which blue-liquid is obtained on reacting equimolar amounts of two gases at -30℃?

•  N₂O
•  N₂O₃
• N₂O₄
•  N₂O₅

Solution
NO + NO₂ → N₂O₃

Q7.Which is a set of acid salts and can react with base?

•  NaH₂PO₂, Na₂HPO₃,NaH₂PO₄
•  Na₂HPO₃, NaH₂PO₃, Na₂HPO₄
•  NaHCO₃, NaH₂PO₃, Na₂HPO₄
•  All of the above

Solution
NaHCO₃, NaH₂PO₃, Na₂HPO₄

Q8.Hardening of cement is due to

•  Dehydration
•  Hydrolysis
•  Hydration and hydrolysis
•  Polymerization

Solution
Hydration is an exothermic process

Q9.H₃BO₃ is

•  Monobasic acid and weak Lewis acid
•  Monobasic and weak Bronsted acid
•  Monobasic and strong Lewis acid
•  Tribasic and weak Bronsted acid

Solution
Monobasic acid and weak Lewis acid

Q10. Boron nitride has the structure of the type

•  Both diamond and graphite
•  Graphite
•  Diamond
• NaCl

Solution
Hexagonal boron nitride (h−BN) is the equivalent in the structure of graphite. Like graphite, its plate-like microstructure and layered lattice structure give it good lubricating properties.