NEET Chemistry The S Block Elements MCQs Set A

Question: The correct increasing order of densities of alkali metals is

• a) Li < Na < K < Rb < Cs
• b) Cs < Rb < K < Na < Li
• c) Li < K < Na < Rb < Cs
• d) K < Na < Li < Rb < Cs

Answer: Li < K < Na < Rb < Cs

Question: Which one of the following alkali metals is the most metallic?

• a) Li
• b) Na
• c) K
• d) Cs

Answer: Cs

Question: The metallic lusture exhibited by sodium is due to

• a) Diffusion of Na⁺ ions
• b) Oscillation of loose electrons
• c) Excitation of free protons
• d) Existence of body centred cubic lattice

Answer: Oscillation of loose electrons

Question: Which one of the following ions has the largest size in aqueous solution?

• a) Rb⁺
• b) Na⁺ 
• c) K⁺ 
• d) Li⁺

Answer: Li⁺

Question: Which among the following is the strongest reducing agent?

• a) K
• b) Na
• c) Al
• d) Mg

Answer: K

Question: Sodium chloride gives a golden yellow colour to the bunsen flame, which is due to

• a) Sublimation of metallic sodium to give yellow vapour
• b) Photosensitivity of sodium
• c) Low ionization potential of sodium
• d) Emission of excess of energy absorbed as a radiation in the visible region

Answer: Emission of excess of energy absorbed as a radiation in the visible region

Question: Which of the following hydride is the most stable?

• a) LiH
• b) KH
• c) NaH
• d) CsH

Answer: LiH

Question: Which of the following oxides is the most basic in nature?

• a) Na₂O 
• b) BeO
• c) Li₂O 
• d) H₂O

Answer:  Na₂O 

Question:  Na₂CO₃ can be manufactured by Solvay’s process but K₂CO₃ cannot be prepared because

• a) K₂CO₃ is more soluble 
• b) K₂CO₃ is less soluble
• c) KHCO₃ is more soluble than NaHCO₃
• d) KHCO₃ is less soluble than NaHCO₃

Answer:  KHCO₃ is more soluble than NaHCO₃

Question: Which hydroxide decomposes on heating?

• a) NaOH
• b) KOH
• c) LiOH
• d) RbOH

Answer: LiOH

Question: Solvay’s process is used for the manufacture of

• a) Sodium metal
• b) Washing soda
• c) Bleaching powder
• d) Quick lime

Answer: Washing soda

Question: In the manufacture of sodium hydroxide, by product obtained is

• a) O₂ 
• b) Cl₂
• c) Na₂CO₃
• d) NaCl

Answer:  Cl₂

Question: Which of the following alkali metal bicarbonates readily decomposes?

• a) LiHCO₃
• b) KHCO₃
• c) CsHCO₃ 
• d) NaHCO₃

Answer:  LiHCO₃

Question:  In the preparation of sodium carbonate (Na₂CO₃) which of the following is used as raw material?

• a) Slaked lime
• b) Brine
• c) Quick lime
• d) Sodium hydroxide

Answer: Brine

Question: The polarizing power of magnesium is nearly same as

• a) Lithium
• b) Sodium
• c) Potassium
• d) Cesium

Answer: Lithium

More Questions...........................................

Question: Which of the following halides has the highest melting point?

• a) NaCl
• b) NaBr
• c) NaF
• d) NaI

Answer: NaF

Question: The first ionisation energies of alkaline earth metals are higher than those of the alkali metals because

• a) There is increase in the nuclear charge of the alkaline earth metals
• b) There is decrease in the nuclear charge of the alkaline earth metals
• c) There is no change is the nuclear charge
• d) All of these

Answer: There is increase in the nuclear charge of the alkaline earth metals

Question: The most electropositive metal among the alkaline earth metal is

• a) Be
• b) Mg
• c) Ca
• d) Ba

Answer: Ba

Question:  Why does magnesium form Mg²⁺ and not Mg⁺?

• a) Magnesium (II) is insoluble in water
• b) Commonly higher oxidation states are preferred by metals
• c) Ionic radius of Mg (II) is smaller than of Mg (I)
• d) High hydration energy as well as high lattice energy of divalent magnesium ion

Answer: High hydration energy as well as high lattice energy of divalent magnesium ion

Question: Which of the following alkaline earth metal does not impart any colour to flame?

• a) Be
• b) Mg
• c) Ca
• d) Sr

Answer: Mg

Question: Lime water is an aqueous solution of

• a) MgSO₄  
• b) Ca(OH)₂
• c) CaCO₃ 
• d) CaSO₄

Answer:  Ca(OH)₂

Question: Which one of the following chlorides has maximum tendency to form hydrate?

• a) BaCl₂ 
• b) NaCl
• c) MgCl₂
• d) LiCl

Answer:  MgCl₂

Question: Setting of Plaster of Paris involves

• a) Oxidation with atmospheric oxygen
• b) Combination with atmospheric CO₂
• c) Dehydration
• d) Hydration

Answer: Hydration

Question: Which of the following is ‘dead burnt plaster’?

• a) CaCO₃
• b)

  

• c) CaSO₄·2H₂O
• d) CaSO₄

Answer:  CaSO₄

Question:  Identify the unknown product (x) in the following reaction Milk of lime + Cl₂→ x + CaCl₂+ H₂O

• a) Ca(OCl)₂ 
• b) Ca(OH)₂ 
• c) CaO
• d) CaCO₃

Answer:  Ca(OCl)₂ 

Question: Formula of Gypsum is

• a) CaSO₄·2H₂O 
• b) CaSO₄· ½ H₂O 
• c) 2CaSO₄·H₂O 
• d) CaSiO₃

Answer:  CaSO₄·2H₂O 

Question: Which one of the following compounds is the most soluble in water?

• a) Mg(OH)₂ 
• b) Sr(OH)₂
• c) Ca(OH)₂  
• d) Ba(OH)₂

Answer:  Ba(OH)₂

Question: Which of the following metals is most commonly used in photochemical cells?

• a) Lithium
• b) Calcium
• c) Caesium
• d) Francium

Answer: Caesium

Question: Which of the following is an amphoteric oxide?

• a) CaO
• b) NaOH
• c) BeO
• d) LiOH

Answer: BeO

Question: Which of the following statement is true for all the alkali metals?

• a) Their nitrates decompose on heating to give NO₂ and O₂
• b) Their carbonates decompose on heating to give CO₂ and metal oxide
• c) They react with oxygen to give mainly the oxide MO₂
• d) They react with halogens to give halides M⁺X^–

Answer:  They react with halogens to give halides M⁺X^–

Question: Which of these give oxide on strong heating?

• a) LiNO₃  
• b) NaNO₃
• c) KNO₃  
• d) RbNO₃

Answer:  LiNO₃  

Question: Which among the following shows the tendency to form peroxide?

• a) Li
• b) Mg
• c) Be
• d) Ba

Answer: Ba

Question: Which one of the following statements is correct? The chlorides of group II metals

• a) Are all hygroscopic in nature
• b) Increase in lattice enthalpy from BeCl₂ to BaCl₂
• c) Decrease in m.p. from BeCl₂ to BaCl₂
• d) Are all insoluble except BaCl₂

Answer: Are all hygroscopic in nature

Question: The solubility order of the chlorides of the alkali metals is

• a) NaCl > KCl > RbCl > CsCl
• b) CsCl > RbCl > KCl > NaCl
• c) KCl > NaCl > RbCl > CsCl
• d) CsCl > RbCl > NaCl > KCl

Answer: CsCl > RbCl > NaCl > KCl

Question: The thermal stability order of the carbonates is

• a) Na₂CO₃> K₂CO₃> BeCO₃> BaCO₃ 
• b) K₂CO₃> Na₂CO₃> BaCO₃> BeCO₃
• c) BaCO₃> BeCO₃> K₂CO₃> Na₂CO₃
• d) BeCO₃> Na₂CO₃> BaCO₃> K₂CO₃

Answer:  K₂CO₃> Na₂CO₃> BaCO₃> BeCO₃

Question: The thermal stability of alkaline earth metal carbonates increases from Be to Ba. This is because

• a) Covalent nature decreases and Ionic nature increases
• b) Lattice energy increases
• c) Electropositive nature decreases
• d) None of these

Answer: Covalent nature decreases and Ionic nature increases

Question: The solubility of sulphates in water decreases from MgSO₄ to BaSO₄ . It is due to the fact that

• a) Ionic nature increases
• b) Size of M²⁺ ion increases
• c) Lattice energy decreases
• d) Hydration enthalpy of M²⁺ ions decreases

Answer:  Hydration enthalpy of M²⁺ ions decreases

Question: Which of the following order is correct for thermal stability?

• a) MgCO₃< CaCO₃< BeCO₃
• b) BeCO₃< MgCO₃< CaCO₃
• c) CaCO₃< BeCO₃< MgCO₃
• d) CaCO₃< MgCO₃< BeCO₃

Answer:  BeCO₃< MgCO₃< CaCO₃

Question: Which one of the following statements concerning the compounds of Lithium is false?

• a) The hydroxide, carbonate, nitrate, decompose to give the oxide on heating
• b) It is the most electronegative among alkali metals
• c) The hydrogen carbonate cannot be isolated as a stable solid
• d) It forms a peroxide but not superoxide

Answer: It forms a peroxide but not superoxide

Question: Which of the following statements is incorrect for Be?

• a) Most of its compound are largely covalent
• b) BeCl₂ has bridged covalent structure and is a linear molecule above 1200 K
• c) It has distinctive group properties due to smaller size and high electronegativity
• d) It forms Be²⁺ ions because of the lower value the sum of Ist and 2nd I.E.

Answer:  It forms Be²⁺ ions because of the lower value the sum of Ist and 2nd I.E.

Question: Which of the following is not an acidic salt?

• a) NaH₂PO₂    
• b) NaH₂PO₃ 
• c) NaH₂PO₄
• d) Na₂HPO₄     

Answer:  NaH₂PO₂    

Question: Sodium is usually kept under

• a) Alcohol
• b) Kerosene oil
• c) Water
• d) Petrol

Answer: Kerosene oil

Question: Baking soda is

• a) NaCl
• b) NaHCO₃  
• c) Na₂SO₄
• d) Na₂CO₃

Answer:  NaHCO₃  

Question: Metallic Magnesium is prepared by

• a) Displacement of Mg by iron from MgSO₄ solution
• b) Electrolysis of an aqueous solution of Mg(NO₃)₂
• c) Electrolysis of molten MgCl₂  
• d) Reduction of MgO by aluminium

Answer:  Electrolysis of molten MgCl₂  

Question: Chemical ‘A’ is used for water softening to remove temporary hardness. ‘A’ reacts with sodium carbonate to generate caustic soda. When carbon dioxide is bubbled through ‘A’, it turns cloudy. What is the chemical formula of ‘A’?

• a) CaCO₃  
• b) CaO
• c) Ca(OH)₂
• d) Ca(HCO₃)₂

Answer:  Ca(OH)₂

Question: Alums are not formed by which alkali metal?

• a) Li
• b) K
• c) Na
• d) Cs

Answer: Li

Question:  The electrolysis of molten KCl · MgCl₂· 6H₂O gives

• a) Mg only
• b) K only
• c) K and Mg only
• d) Mg and Cl₂

Answer:  Mg and Cl₂

Question: Epsom salt’s chemical formula is

• a) MgSO₄· 7H₂O   
• b) Mg(OH)₂
• c) 2CaSO₄· H₂O 
• d) BaSO₄

Answer:  MgSO₄· 7H₂O   

Question: Compared with the alkaline earth metals, the alkali metals show

• a) Greater hardness
• b) Higher m.p.
• c) Smaller ionic radii
• d) Lower ionization energy

Answer: Lower ionization energy

Question: Molecular formula of Glauber’s salt is

• a) MgSO₄· 7H₂O 
• b) CuSO₄· 5H₂O
• c) FeSO₄· 7H₂O 
• d) Na₂SO₄· 10H₂O

Answer:  Na₂SO₄· 10H₂O

Question: Which is not the compound of sodium?

• a) Chile salt petre
• b) Salt petre
• c) Glauber's salt
• d) Soda ash

Answer: Salt petre

Question:

Product D is

• a) CaCl₂  
• b) Ca(OH)₂
• c) CaCl₂.6H₂O 
• d) CaOCl₂

Answer:  CaOCl₂

Question: Correct order of solubility

• a) BeSO₄> BaSO₄ 
• b) LiCl > LiF
• c) NaHCO₃< KHCO₃ 
• d) All of these

Answer: All of these

Question: Among the oxides of group 2, least basic is

• a) MgO
• b) CaO
• c) SrO
• d) BaO

Answer: MgO

Question: Beryllium on ignition in air gives

• a) BeO
• b) Be₃N₂
• c) Both (1) & (2)
• d) BeC

Answer: Both (1) & (2)

Question:  Na₂CO₃+ H₂O + CO₂ → (A). White crystalline powder (A) on reaction with phenolphthalein gives

• a) Pink colour
• b) Yellow colour
• c) Orange colour
• d) No colour

Answer: Pink colour

Question: Composition of baking soda is

• a) Starch
• b) Ca(H₂PO₄)₂
• c) NaHCO₃ 
• d) All of these

Answer:  NaHCO₃ 

Question: Which of the following statement is true?

• a) NaHCO₃ is strongly basic in nature
• b) Pure NaCl is hygroscopic
• c) On increasing temperature increase in solubility of NaCl in water occurs
• d) All of these

Answer: On increasing temperature increase in solubility of NaCl in water occurs

Question:   Alkaline earth metals form hydrated crystalline solids such as MgCl₂· 6H₂O and CaCl₂· 6H₂O. This is due to

• a) Smaller ionic size
• b) Increased charge on ions
• c) Higher hydration enthalpies
• d) High oxidation potential

Answer: Higher hydration enthalpies

Question: On heating sodium hydrogen carbonate, the product formed is

• a) Na₂O + CO₂+ H₂O 
• b) Na₂CO₃+ CO₂
• c) Na₂CO₃+ H₂O + CO₂ 
• d) Na₂CO₃+ H₂O

Answer:  Na₂CO₃+ H₂O + CO₂