CBSE Class 11 Chemistry s-Block Elements MCQs Set C

Question: The ionic mobility of alkali metal ions in aqueous solution is maximum for
a) Li⁺
b) Na⁺
c) K⁺
d) Rb⁺
Answer: d

Question: The element which on burning in air gives peroxide is
a) lithium
b) sodium
c) rubidium
d) caesium
Answer: b

Question: In crystals which one of the following ionic compounds would you expect maximum distance between centres of cations and anions?
a) LiF
b) CsF
c) CsI
d) LiI
Answer: c

Question: Which of the following alkali metal is highly radioactive?
a) Rubidium
b) Caesium
c) Francium
d) Both Rubidium and Francium
Answer: c

 Question: On heating anhydrous Na₂CO₃,.......is evolved
a) CO₂
b) water vapour
c) CO
d) no gas
Answer: d

Question: Which hydride is most stable
a) NaH
b) KH
c) CsH
d) LiH
Answer: d

Question: Which of the following statements is not correct for alkali metals?
a) Alkali metals are the most electropositive metals.
b) Alkali metals exist in free state in nature.
c) These metals have the largest size in a particular period of the periodic table.
d) Both Alkali metals exist in free state in nature. and These metals have the largest size in a particular period of the periodic table.
Answer: b

Question: The alkali metals have low melting point. Which of the following alkali metal is expected to melt if the room temperature rises to 30°C?
a) Na
b) K
c) Rb
d) Cs
Answer: d

Question: Identify the correct statement
a) Elemental sodium can be prepared and isolated by electrolysing an aqueous solution of sodium chloride
b) Elemental sodium is a strong oxidising agent
c) Elemental sodium is insoluble in ammonia
d) Elemental sodium is easily oxidised
Answer: d

Question: The process associated with sodium carbonate manufacture is known as
a) Chamber
b) Haber
c) LeBlanc
d) Castner
Answer: c

Question: Which of the following has density greater than water?
a) Li
b) Na
c) K
d) Rb
Answer: d

Question: Which of the following represents a correct sequence of reducing power of the following elements?
a) Li > Cs > Rb
b) Rb > Cs > Li
c) Cs > Li > Rb
d) Li > Rb > Cs
Answer: a

Question: Which of the following is non-metallic?
a) B
b) Be
c) Mg
d) Al
Answer: a

Question: Which is most basic in character ?
a) CsOH
b) KOH
c) NaOH
d) LiOH
Answer: a

Question: For an aqueous solution under an electric field which of the following have lowest mobility ?
a) Li⁺
b) Na⁺
c) K⁺
d) Rb⁺
Answer: a

Question: Washing soda has formula
a) Na₂CO₃.7H₂O
b) Na₂CO₃.10H₂O
c) Na₂CO₃.3H₂O
d) Na₂CO₃
Answer: b

Question: In the case of the alkali metals
a) the cation is less stable than the atom
b) the cation is smaller than the atom
c) the cation and the atom have about the same size
d) the cation is larger than the atom
Answer: b

Question: Which is the most basic of the following?
a) Na₂O
b) BaO
c) As₂O₃
d) Al₂O₃
Answer: a

Question: Which of the following does not illustrate the anomalous properties of lithium?
a) The melting point and boiling point of Li are comparatively high
b) Li is much softer than the other group I metals
c) Li forms a nitride Li3N unlike group I metals
d) The ion of Li and its compounds are more heavily hydrated than those of the rest of the group
Answer: b

Question: Which of the following are found in biological fluids Na+, Mg²⁺, Ca²⁺, K+, Sr²⁺, Li+ and Ba²⁺
a) Mg²⁺, Ca²⁺, and Sr²⁺
b) Na^{2 +}and K⁺
c) Na⁺, K+, Mg²⁺and Ca²⁺
d) Sr⁺, Li and Ba²⁺
Answer: c

Question: Which of the following is used as a source of oxygen in space capsules, submarines and breathing masks ?
a) Li₂O
b) Na₂O₂
c) KO₂
d) K₂O₂
Answer: c

 Question: How NH₃ is recovered in Solvay process?
a) By reaction of NH₄Cl and Ca(OH)₂
b) By reaction of NH₄HCO₃ and NaCl
c) By reaction of (NH₄)₂CO₃ with H₂O
d) By any of the above
Answer: a

Question: What is the colour of solution of alkali metals in liquid ammonia?
a) Bronze
b) Blue
c) Green
d) Violet
Answer: b

Question: In Solvay ammonia process, sodium bicarbonate is precipitate due to
a) presence of NH₃
b) reaction with CO₂
c) reaction with brine solution
d) reaction with NaOH
Answer: c

Question: The elements of group 1 provide a colour to the flame of Bunsen burner due to
a) low ionization potential
b) low melting point
c) softness
d) presence of one electron in the outermost orbit
Answer: a

Question: Which one of the following properties of alkali metals increases in magnitude as the atomic number rises ?
a) Ionic radius
b) Melting point
c) Electronegativity
d) First ionization energy.
Answer: a

Question: The most stable compound is
a) LiF
b) LiCl
c) LiBr
d) LiI
Answer: a

Question: The metal that produces red-violet colour in the nonluminous flame is
a) Ba
b) Ag
c) Rb
d) Pb
Answer: c

Question: Which of the following pairs of substances would give same gaseous product on reaction with water?
a) Na and Na₂O₂
b) Ca and CaH₂
c) Ca and CaO
d) Ba and BaO₂
Answer: b

Question: Which of the following metal is used as a coolant in breeder nuclear reactors?
a) Potassium
b) Sodium
c) Caesium
d) Rubidium
Answer: b

Question: Which is manufactured by electrolysis of fused NaCl ?
a) NaOH
b) Na
c) NaClO
d) NaClO₃.
Answer: b

Question: The outer electronic configuration of alkaline earth metal is
a) ns²
b) ns¹
c) np⁶
d) nd¹⁰
Answer: a

Question: Baking soda is
a) NaHCO₃
b) K₂CO₃
c) Na₂CO₃
d) NaOH
Answer: a

Question: Which of the following is the most abundant ion within cell fluids?
a) Sodium ions
b) Potassium ions
c) Calcium ions
d) None of the options
Answer: b

Question: Among LiI, NaI, KI, the one which is more ionic and more soluble in water is
a) KI
b) NaI
c) LiI
d) None of the options
Answer: a

Question: Which of the following has largest size ?
a) Na
b) Na⁺
c) Na^–
d) Can’t be predicted
Answer: c

Question: Ionization potential of Na would be numerically the same as
a) electron affinity of Na⁺
b) electronegativity of Na⁺
c) electron affinity of He
d) ionization potential of Mg
Answer: a

Question: Which one of the alkali metals, forms only, the normal oxide, M₂O on heating in air ?
a) Rb
b) K
c) Li
d) Na
Answer: c

Question: Sodium carbonate is manufactured by Solvay process. The products which can be recycled are
a) CO₂ and NH₃
b) CO₂ and NH₄Cl
c) NaCl and CaO
d) CaCl₂ and CaO.
Answer: a

Question: Na metal is stored in
a) C₆H₆
b) kerosene
c) alcohol
d) toluene
Answer: b

Question: Why Solvay process cannot be extended to the manufacture of potassium carbonate?
a) Ammonium hydrogen carbonate does not react with potassium chloride.
b) Potassium hydrogen carbonate is too soluble to be precipitated by the addition of ammonium hydrogencarbonate to a saturated solution of potassium chloride.
c) Ammonium carbonate is precipitated out instead of potassium hydrogen carbonate on reaction of ammonium hydrogen carbonate with potassium chloride
d) None of the options
Answer: b

 Question: Which of the following metal is used along with lithium to make the alloy named ‘white metal’ ?
a) Nickel
b) Aluminium
c) Silver
d) Lead
Answer: d

Question: Baking powder contains :
a) NaHCO₃, Ca(H₂PO₂)₂ and starch
b) NaHCO₃, Ca(H₂PO₂)₂
c) NaHCO₃, starch
d) NaHCO₃
Answer: a

 Question: The products obtained on heating LiNO₂ will be
a) Li₂O+ NO₂ +O₂
b) Li₃N + O₂
c) Li₂O+ NO+ O₂
d) LiNO₃ + O₂
Answer: a

Question: Why lithium react less vigorously with water than other alkali metals?
a) Lithium has most negative E ^Θ value
b) Lithium has small size and very high hydration energy.
c) Lithium has least negative E ^Θ value
d) Both Lithium has most negative E ^Θ value and Lithium has small size and very high hydration energy.
Answer: b

Question: Electronic configuration of calcium atom may be written as
a) [Ne], 4p²
b) [Ar], 4s²
c) [Ne], 4s²
d) [Ar], 4p²
Answer: b

 Question: Which compound will show the highest lattice energy ?
a) RbF
b) CsF
c) NaF
d) KF
Answer: c

Question: Complete the following two reactions.
(i) 4LiNO₃ → x + O₂
(ii) 2NaNO₃ → y + O₂
a) x = LiNO₂, y = NaNO₂
b) x = Li₂O + NO₂, y = Na₂O + NO₂
c) x = Li₂O + NO₂, y = NaNO₂
d) x = LiNO₂, y = Na₂O + NO₂
Answer: c

Question: Which of the following is/are present as impurity in crude sodium chloride, obtained by crystallisation of brine solution?
(i) Sodium sulphate
(ii) Calcium chloride
(iii) Magnesium chloride
(iv) Potassium chloride
a) (i), (ii) and (iv)
b) (ii) and (iii)
c) (iii) and (iv)
d) (i), (ii) and (iii)
Answer: d

Question: Group 2 elements are called alkaline earth metals why? Choose the correct reason(s).
(i) Hydroxides formed by group 2 elements are alkaline in nature.
(ii) Their metal oxides are found in the earth’s crust.
(iii) Their oxides are alkaline in nature
(iv) Group 2 elements react with alkalies.
a) (i) and (ii)
b) (ii) and (iv)
c) (i), (ii) and (iii)
d) (ii) and (iii)
Answer: c