Objective Type Questions and Answers on Class 11 Chemistry Chapter 10 The S Block Elements

1 The alkali metals are low melting. 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

View Answer

Answer:Cs

2 Alkali metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously?

A Li

B Na

C K

D Cs

View Answer

Answer:Li

3 The reducing power of a metal depends on various factors. Suggest the factor which makes Li, the strongest reducing agent in aqueous solution.

A Sublimation enthalpy

B Ionisation enthalpy

C Hydration enthalpy

D Electron-gain enthalpy

View Answer

Answer:Hydration enthalpy

4 Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?

A MgCO₃

B CaCO₃

C SrCO₃

D BaCO₃

View Answer

Answer:BaCO₃

5 Which of the carbonates given below is unstable in air and is kept in CO2 atmosphere to avoid decomposition.

A BeCO3

B MgCO3

C CaCO3

D BaCO3

View Answer

Answer:BeCO3

6 Metals form basic hydroxides. Which of the following metal hydroxide is the least basic?

A Mg(OH₂

B Ca(OH)₂

C Sr(OH)₂

D Ba(OH)₂

View Answer

Answer:Mg(OH₂

7 Some of the Group 2 metal halides are covalent and soluble in organic solvents. Among the following metal halides, the one which is soluble in ethanol is

A BeCl₂

B MgCl₂

C CaCl₂

D SrCl₂

View Answer

Answer:BeCl₂

8 The order of decreasing ionisation enthalpy in alkali metals is

A Na > Li > K > Rb

B Rb < Na < K < Li

C Li > Na > K > Rb

D K < Li < Na < Rb

View Answer

Answer:Li > Na > K > Rb

9 The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to

A Ionic nature of lithium fluoride

B High lattice enthalpy

C High hydration enthalpy for lithium ion.

D Low ionisation enthalpy of lithium atom

View Answer

Answer:High lattice enthalpy

10 Amphoteric hydroxides react with both alkalies and acids. Which of the following Group 2 metal hydroxides is soluble in sodium hydroxide?

A Be(OH)₂

B Mg(OH)₂

C Ca(OH)₂

D Ba(OH)₂

View Answer

Answer:Be(OH)₂

11 In the synthesis of sodium carbonate, the recovery of ammonia is done by treating NH₄Cl with Ca(OH)₂. The by-product obtained in this process is

A CaCl₂

B NaCl

C NaOH

D NaHCO₃

View Answer

Answer:CaCl₂

12 When sodium is dissolved in liquid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to

A ammoniated electron

B sodium ion

C sodium amide

D ammoniated sodium ion

View Answer

Answer:ammoniated electron

13 By adding gypsum to cement

A setting time of cement becomes less.

B setting time of cement increases.

C colour of cement becomes light.

D shining surface is obtained.

View Answer

Answer:setting time of cement increases.

14 Dead burnt plaster is

S Block Element

A (i)

B (ii)

C (iii)

D (iv)

View Answer

Answer:(i)

15 Suspension of slaked lime in water is known as

A lime water

B quick lime

C milk of lime

D aqueous solution of slaked lime

View Answer

Answer:milk of lime

16 Which of the following elements does not form hydride by direct heating with dihydrogen?

A Be

B Mg

C Sr

D Ba

View Answer

Answer:Be

17 The formula of soda ash is

A Na₂CO₃.10H₂O

B Na₂CO₃.2H₂O

C Na₂CO₃.H₂O

D Na₂CO₃

View Answer

Answer:Na₂CO₃

18 A substance which gives brick red flame and breaks down on heating to give oxygen and a brown gas is

A Magnesium nitrate

B Calcium nitrate

C Barium nitrate

D Strontium nitrate

View Answer

Answer: Calcium nitrate

19 Which of the following statements is true about Ca(OH)2?

A It is used in the preparation of bleaching powder

B It is a light blue solid

C It does not possess disinfectant property.

D It is used in the manufacture of cement.

View Answer

Answer:It is used in the preparation of bleaching powder

20 A chemical A is used for the preparation of washing soda to recover ammonia. When CO₂ is bubbled through an aqueous solution of A, the solution turns milky. It is used in white washing due to disinfectant nature. What is the chemical formula of A?

A Ca(HCO₃)₂

B CaO

C Ca(OH)₂

D CaCO₃

View Answer