Free NCERT Solutions For Class 11 Chemistry Chapter 10 : The s-Block Elements Free PDF Download

Question 1:
What are the common physical and chemical features of alkali metals?

Question 2:
Discuss the general characteristics and gradation in properties of alkaline earth metals.

Question 3:
Why are alkali metals not found in nature?

Question 5:
Explain why is sodium less reactive than potassium.

Question 6:
Compare the alkali metals and alkaline earth metals with respect to
(i) ionization enthalpy,
(ii) basicity of oxides,
(iii) solubility of hydroxides.

Question 7:
In what ways lithium shows similarities to magnesium in its chemical behaviour?

Question 8:
Explain why can alkali and alkaline earth metals not be obtained by chemical reduction
method.

Question 9:
Why are potassium and caesium, rather than lithium used in photoelectric cells?

Question 11:
Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why?

Question 13:
Potassium carbonate cannot be prepared by Solvay process. Why?

Question 14:
Why is Li2CO3 decomposed at a lower temperature whereas Na2CO3 at higher temperature?

Question 15:
Compare the solubility and thermal stability of the following compounds of the alkali metals with those of the alkaline earth metals.
(a) Nitrates
(b) Carbonates
(c) Sulphates

Question 16:
Starting with sodium chloride how would you proceed to prepare.
(i) Sodium metal
(ii) Sodium hydroxide
(iii) Sodium peroxide
(iv) Sodium carbonate?

Question 17:
What happens when (i) magnesium is burnt in air, (ii) Quick lime is heated with silica (iii) chlorine reacts with slaked lime (iv) calcium nitrate is heated?

Question 18:
Describe two important uses of each of the following:,
(i) caustic soda
(ii) sodium carbonate
(iii) quick lime

Question 20:
The hydroxides and carbonates of sodium and potassium are easily soluble in water while the
corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.

Question 21:
Describe the importance of the following:
(i) Limestone (ii) Cement (iii) Plaster of Paris.

Question 22:
Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?

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Question 23:
Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in
acetone?

Question 24:
Explain the significance of sodium, potassium, magnesium and calcium in biological fluids.

Question 25:
What happens when
(i) Sodium metal is dropped in water?
(ii) Sodium metal is heated in free supply of air?
(iii) Sodium peroxide dissolves in water?

Question 27:
State as to why
(a) a solution of Na2CO3 is alkaline?
(b) alkali metals are prepared by electrolysis of their fused chlorides?
(c) Sodium is found to be more useful than potassium?

Question 30:
Which of the alkali metal is having least melting point?
(a) Na (b) K (c) Rb (d) Cs

I. Very Short Answer Type Questions

Question 9:
Arrange the following in the increasing order of solubility in water.
MgCl2, CaCl2, SrCl2, BaCl2

Question 12:
What happens when sodium metal is heated in free supply of air?

II. Short Answer Type Questions

Question 3:
Explain the following:
(a) Lithium iodide is more covalent than lithium fluoride.
(b) Lattice enthalpy of LiF is maximum among all the alkali metal halides.

Question 4:
Write the chemical formula of the following compounds.
(i) Chile salt petre (ii) Marble (iii) Brine

Question 5:
Explain the following:
(a) Why Cs is considered as the most electropositive element?
(b) Lithium cannot be used in making photoelectric cells.
(c) Lithium does not form alums.

Question 6:
(a) What makes lithium to show properties uncommon to the rest of the alkali metals?
(b) When is a cation highly polarizing? Which alkali metal cation has the highest polarizing power?

Question 7:
Why are ionic hydrides of only alkali metals and alkaline earth metals are known? Give two examples.

Question 9:
Give the important uses of the following compounds.
(i) NaHCO3 (ii) NaOH

Question 10:
What is the mixture of CaC2 and N2 called? How is it prepared?

III. Long Answer Type Questions

Question 1:
(a) Compare four properties of alkali metals and alkaline earth metals.
(b) What happens when alkali metals are dissolved in ammonia?
(c) MgCl2 is electrolyzed

Question 2:
State as to why
(a) Alkali metals show only +1 oxidation state.
(b) Na and K impart colour to the flame but Mg does not.
(c) Lithium on being heated in air mainly forms the monoxide and not the peroxide.
(d) Li is the best reducing agent in aqueous solution.

IV. Multiple Choice Questions

Question 10:
Which of the following is used in photoelectric cells?
(a) Na (b) K (c) Li (d) Cs

V. Hots Questions

Question 1:
Why are alkali metals soft and have low melting points?

Question 2:
Which out of the following can be used to store an alkali metal?
H2O, C2H5OH and Benzene

Question 3:
Potassium carbonate cannot be prepared by Solvay process. Why?

Question 4:
The hydroxides and carbonates of sodium and potassium are easily soluble in water while the
corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.

Question 5:
Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone?