In This Post we are  providing Chapter-3 The s-block Elements NCERT MCQ for Class 11 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON THE s-BLOCK ELEMENTS

Question 1.
The paramagnetic species is
(a) KO₂
(b) SiO₂
(c) TiO₂
(d) BaO₂

Answer: (a) KO₂

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Question 2.
On dissolving moderate amount of sodium metal in liquid ammonia at low temperature, which one of the following does not occur?
(a) Blue coloured solution is obtained
(b) Na⁺ ions are formed in the solution
(c) Liquid NH₃ becomes good conductor of electricity
(d) Liquid ammonia remain diamagnetic.

Answer: (d) Liquid ammonia remain diamagnetic.

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Question 3.
The substance not likely to contain CaCO₃ is
(a) Dolomite
(b) A marble
(c) Calcined gypsum
(d) Sea shells.

Answer: (c) Calcined gypsum

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Question 4.
TLe active constituent of bleaching powder is
(a) Ca(OCl)₂
(b) Ca(OCl)Cl
(c) Ca(ClO₂)
(d) Ca(ClO₂)Cl

Answer: (b) Ca(OCl)Cl

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Question 5.
Which of the following is the correct order of gradually decreasing basic nature of the oxides?
(a) Al₂O₃, MgO, Cl₂O₇, SO₃
(b) Cl₂O₇, SO₃, Al₂O₃, MgO
(c) SO₃, Cl₂O₇, MgO, Al₂O₃
(d) MgO, Al₂O₃, SO₃, Cl₂O₇

Answer: (d) MgO, Al₂O₃, SO₃, Cl₂O₇

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Question 6.
Among the alkaline earth metals, the element forming the predominantly covalent compound is
(a) Barium
(b) Strontium
(c) Calcium
(d) Beryllium.

Answer: (d) Beryllium.

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Question 7.
Which of the following substances can be used for drying gases?
(a) Calcium carbonate
(b) Sodium carbonate
(c) Sodium bicarbonate
(d) Calcium oxide

Answer: (d) Calcium oxide

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Question 8.
The stability of the following alkali metal chlorides follows the order
(a) LiCl > KCl > NaCl > CsCl
(b) CsCl > KCl > NaCl > LiCl
(c) NaCl > KCl > LiCl > CsCl
(d) KCl > CsCl > NaCl > LiCl

Answer: (a) LiCl > KCl > NaCl > CsCl

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Question 9.
Solubility of carbonates decrease down the Magnesium group due to decrease in
(a) Entropy of solution formation
(b) Lattice energies of solids
(c) Hydration energy of cations
(d) Inter-ionic attraction.

Answer: (c) Hydration energy of cations

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Question 10.
In curing cement plasters, water is sprinkled from time to time. This helps in
(a) Converting sand into silicic acid
(b) Keeping it cool.
(c) Developing interlocking like crystals of hydrated silicates
(d) Hydrating sand and gravel mixed with cement.

Answer: (c) Developing interlocking like crystals of hydrated silicates

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Question 11.
Bleaching powder loses its power on keeping for a long time because
(a) It changes into calcium hypochlorite
(b) It changes into calcium chloride and calcium hydroxide
(c) It absorbs moisture
(d) It changes into calcium chloride and calcium chlorate

Answer: (d) It changes into calcium chloride and calcium chlorate

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Question 12.
A metal M readily forms water soluble sulphate MSO₄, water insoluble hydroxide M(OH)₂ and oxide MO which becomes inert on heating. The hydroxide is soluble in NaOH. The metal M is
(a) Be
(b) Mg
(c) Ca
(d) Sr

Answer: (a) Be

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Question 13.
KO₂ (Potassium superoxide) is used in oxygen cylinders in space and submarines because it
(a) Absorbs CO₂ and increases O₂ content
(b) Eliminates moisture
(c) Absorbs CO₂
(d) Produces ozone

Answer: (a) Absorbs CO₂ and increases O₂ content

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Question 14.
Which one is used as an air purifier in space craft?
(a) Quick lime
(b) Slaked lime
(c) Potassium superoxide
(d) Anhydrous CaCl₂

Answer: (c) Potassium superoxide

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Question 15.
The correct order of increasing ionic character is
(a) BeCl₂ < MgCl₂ < CaCl₂ < BaCl₂
(b) BeCl₂ < MgCl₂ < BaCl₂ < CaCl₂
(c) BeCl₂ < BaCl₂ < MgCl₂ < CaCl₂
(d) BaCl₂ < CaCl₂ < MgCl₂ < BeCl₂

Answer: (a) BeCl₂ < MgCl₂ < CaCl₂ < BaCl₂

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