NCERT Class 11 Chemistry Chapter 10 S Block Elements Very Short Answer Questions

NCERT Solutions For Class 11 Chemistry Chapter 10 S Block Elements Very Short Question And Answers

Question 1. Explain why sodium carbonate is used in fire extinguishers.
Answer: In fire extinguishers, Na₂CO₃ is used as it reacts with dil. H₂SO₄ to produce CO₂

Question 2. Why docs sodium hydrogen carbonate called baking soda?
Answer: NaHCO₃ is an important ingredient in baking powder. Thus, it is also called baking soda.

Question 3. Name a bivalent element whose oxide is soluble in excess NaOH solution.
Answer:  Beryllium; BeO + 2NaOH→ Na₂BeO₂ + H₂O

Question 4. Which of the alkali metals exhibits abnormal behavior?
Answer: Lithium

Read and Learn More NCERT Class 11 Chemistry Very Short Answer Questions

Question 5. Which alkali metal is most abundant in the earth’s crust?
Answer: Sodium (Na)

Question 6. What type of crystal lattice is formed by the alkali metals?
Answer:  Alkali metals form a body-centered cubic lattice

Question 7. Name an alkali metal that is used in Lassaigne’s test for the detection of nitrogen, sulfur, and halogen in the organic compounds.
Answer: Sodium

Question 8. Write the general electronic configuration of group-2 elements.
Answer: Electronic configuration: [Inert gas] ns²

Question 9. Which element of group 2 shows abnormal behavior?
Answer: Beryllium (Be) shows abnormal behavior

Question 10. Why CaF₂ is considered the most important fluoride salt among all the fluoride salts of alkaline earth metals?
Answer:  CaF₂ is the most important source for the preparation of fluorine

Question 11. Which out of LIF of Lil is more covalent?
Answer:  Lil is more covalent.

Question 12. Which alkali metal carbonate easily liberates CO₂ on heating?
Answer: Li₂CO₃ easily liberates CO₂ on heating.

Question 13. Which alkali metal chloride imparts violet color to the bunsen burner flame?
Answer: Potassium chloride (KCl)

Question 14. Which alkali metal hydride is used as a source of hydrogen for filling up meteorological balloons?
Answer: Lithium hydride (LiH).

Question 15. Name the products formed in the following reaction. Explain Lil + KF→? + ?
Answer: LiF and KI. The larger K⁺ ion stabilizes the larger I^– ion while the smaller Li⁺ ion stabilizes the smaller F- ion.

Question 16.  What is water glass?
Answer: Sodium silicate (NaOSiO₃).

Question 17. Which alkali metal combines with nitrogen to form the corresponding nitride?
Answer: Lithium (Li).

Question 13. What are the raw materials used for the manufacture of sodium carbonate by the Solvay process?
Answer: The raw materials are NaCl, CaCO and NH₃.

Question 18. Which out of the Na₂CO₃ solution & NaHCO₃ solution, changes the color of phenolphthalein into pink?
Answer: Na₂CO₃ solution.

Question 19. What is the main ingredient of baking powder?
Answer: Sodium bicarbonate (NaHCO₃).

Question 20. Which compound is used to treat the flue gases from coal and oil-fired power stations and to remove SO₂ and H₂SO₄ responsible for acid rain?
Answer: Na₂CO₃.

Question 21. What are the ingredients of the fusion mixture that is used in dry tests in inorganic analysis?
Answer: K₂CO₃ and Na₂CO₃

Question 22. Which alkaline earth metal is the most abundant in the earth’s crust?
Answer: Calcium (Ca).

Question 23. Which alkaline earth metal is radioactive?
Answer: Radium (Ra).

Question 24. Name the metal of group-2 which is used to prepare Grignard reagent.
Answer: Magnesium (Mg).

Question 25. Name the element of group 2 that resembles lithium in characteristics.
Answer: Magnesium (Mg).

Question 26. Which alkaline earth metals do not impart any color to the flame of a Bunsen burner?
Answer: Be anil Mg.

Question 27. Name an alkaline earth metal compound that can be used as a portable source of hydrogen.
Answer: Calcium hydride (CaH₂).

Question 28. Which Gr-2 metal forms covalent compounds?
Answer: Beryllium (Be).

Question 29. Which Gr-2 metal burns readily when exposed to air?
Answer: Barium (B a).

Question 30. Which alkaline earth metal reacts with alkali to form hydrogen gas?
Answer: Beryllium (Be).

Question 31. What is the composition of the alloy, electron?
Answer: 95% of Mg+ and 5% of Zn.

Question 32. Which reagent is used to analyze Ca²⁺ and Mg²⁺ ions quantitatively?
Answer: EDTA (Ethylenediaminetetraacetic acid).

Question 33. What is the medicinal name of the aqueous solution of Mg(OH)₂?
Answer: Milk of magnesia.

Question 34. What is anhydrous?
Answer: Magnesium perchlorate, Mg(ClO₄)₂ is known as anhydrous.

Question 35. How will you distinguish between BeSO₄ & BaSO₄?
Answer: BeSO₄ is water soluble but BaSO₄ is insoluble in water.

Question 36. Which out of MgCO₃, SrCO_3, and BaCO₄, possesses the highest thermal stability?
Answer: BaCO₄ has the highest thermal stability.

Question 37. Distinguish between Be(OH)₂ and Ba(OH)₂
Answer: Be(OH)₂ is soluble in caustic soda solution while Ba(OH)2 is insoluble in it.

Question 38. Why is BeCl₂ soluble in organic solvents?
Answer: BeCl₂ is covalent.

Question 39. Which Gr-2 metal carbonate is unstable in the air?
Answer: BeCO₃.

Question 40. Which alkaline earth metal sulfate is useful in diagnosing stomach ulcers by X-ray?
Answer: BaSO₄ (in ‘barium meal’ X-ray).

Question 41. BeO is covalent but still, it has a much higher melting point— mention the reason.
Answer: This is due to its polymeric structure.

Question 42. What is the difference between lime water and milk of lime?
Answer: Mg²⁺

Question 43. Write a reaction by which BeCl₂ can be prepared.
Answer:

Question 44. What is the composition of soda lime used for the preparation of hydrocarbons in the laboratory?
Answer: NaOH and CEO
.
Question 45. ED Name two acidic oxides which react similarly with calcium hydroxide [Ca(OH)₂].
Answer: CO₂ and SO₂.

Question 46. Which alkaline earth metal oxide is used as a flux in metallurgy to remove siliceous impurities?
Answer: Calcium oxide (CaO)

Question 47. What is the commercial name of the disinfectant powder obtained when Cl2 reacts with slightly moist slaked lime at 40°C?
Answer: Bleaching powder.

Question 48. What is Plaster of Paris?
Answer: Hemihydrate of calcium sulphate, (CaSO₄)₂-H₂O is called Plaster of Paris.

Question 49. What type of impurities in gypsum should be avoided in preparing Plaster of Paris from it?
Answer: Carbonaceous impurities are to be avoided.

Question 50. Why KNO₃ is used instead of NaNO₃ in gunpowder?
Answer: NaNO₃ is deliquescent. Hence, KNO₃ is preferred over NaNO₃ for the preparation of gunpowder.

Question 51. What do you mean by ‘black ash
Answer: A mixture of sodium carbonate (Na₂CO₃) and calcium sulfide (CaS) is called black

Question 52. What happens when magnesium is heated with | acetylene at 875K?
Answer: Magnesium on heating with acetylene at 875K forms magnesium carbide (Mg₃C₂)

Question 53. Write the composition of gunpowder.
Answer: Gunpowder is an explosive mixture containing KNO₃ along with charcoal and sulfur

Question 54. Why is Na₂S₂O₃ used in photography?
Answer: In photography, Na₂S₂O₃ is used to dissolve the unexposed AgBr.

Question 55. The affinity of sodium towards water is used in drying benzene. Explain.
Answer: Sodium does not react with benzene. Hence it can be used effectively for drying benzene.

Question 56.  Name a pair of elements that exhibits a diagonal relationship.
Answer:  Lithium (Li) and magnesium (Mg) CO₂

Question 57. Name an alkaline earth metal.
Answer: Calcium (ca)

Question 58. Write the balanced equation for the reaction when water is added to calcium carbide.
Answer: CaC₂ + 2M₂O →MC=CH + Ca(OH)₂

Question 59. Which alkali metal ion has the highest polarising power?
Answer: Li⁺

Question 60. What are the common oxidation states exhibited by group-1 and group-2- 2 metals respectively?
Answer: +2 And +1 respectively

Question 61. Name the alkali metals which form superoxides when heated with excess oxygen.
Answer: K, Rb, and cs

Question 62. Which one is the lightest and which one is the heaviest of all the metals?
Answer: Lithium (Li) and Osmium(os) respectively

Question 63. What is the composition of the white powder obtained when metallic magnesium is burnt in the air?
Answer: A mixture of MgO and Mg₃N₂

Question 64. Name two metals of group 2 which do not impart any color to the flame.
Answer: Mg and Be

Question 65. Which alkali metal cannot be stored in kerosene?
Answer: Li

Question 66. Which alkali metal is used as a scavenger in metallurgy to remove O₂ and N₂ gases?
Answer: Li

Question 67. Which Gr-2 metal carbide reacts with water to produce methane?
Answer: Be₂ C

Question 68. In an aqueous solution, which alkali metal ion has the lowest mobility?
Answer: Li⁺

Question 69. Which is the most abundant alkaline earth metal in the earth’s crust?
Answer: Calcium

Question 70. Name one group-2 metal.
Answer: Chlorophyll

Question 71. Which alkali metal ion forms a stable complex with 18- crown-6
Answer: Potassium(K)

Question 72. Which alkaline earth metal is largely used as a lightweight construction metal?
Answer: Mg

Question 73. Which alkaline earth metal forms an organometallic compound known as Grignard reagent?
Answer: Mg

Question 74. Which alkali and alkaline earth metals are radioactive?
Answer: Fr and Ra

Question 75.  The salts of which alkali metals are commonly hydrated?
Answer: Li

Question 76. Which alkali metal acts as the strongest reducing agent in aqueous solution?
Answer: Li

Question 77. Which is the least stable alkali metal carbonate?
Answer: Li₂CO₃

Question 78. What is baryta water?
Answer: Ba(OH ₂ solution

Question 79. Which alkaline earth metal hydroxide is most soluble in water?
Answer: Ba(OH)₂

Question 80. Which alkaline earth metal imparts crimson color to flame?
Answer: Srcl₂

Question 81. BeO is covalent and still has high melting points — why?
Answer: It is polymeric

Question 82. What is anhydrous?
Answer: Magnesium perchlorate Mg(ClO₄)₂

Question 83. Which alkaline earth metal carbonate can be kept only in an atmosphere of CO₂?
Answer: BeCO₃

Question 84. Which alkaline earth metal chloride is used as a desiccant in the laboratory?
Answer: CaCl₂

Question 85. The basic strength of which alkali metal hydroxide is the highest?
Answer: CsOH

Question 86. Which alkaline earth metal hydroxide is amphoteric?
Answer: Be(OH)₂

Question 87. How will you distinguish between Ba(OH)₂ and Be(OH)₂?
Answer: Be(OH)₂ dissolves in alkali but Ba(OH)₂ does not

Question 88. What are the raw materials used for the manufacture of washing soda by the Solvay process?
Answer: NaCl, CaCO₃ and NH₃

Question 89. What is soda ash?
Answer: . Anhydrous Na₂CO₃

Question 90. Which alkaline earth metal hydroxide and alkali metal carbonate are used for softening hard water?
Answer: Ca(OH)₂ and Na₂CO₃;

Question 91. What is the formula of Plaster of Paris?
Answer: 2CaSO₄ .H₂O

Question 92. What is dead burnt plaster?
Answer: Anhydrous CaSO₄;

Question 93. Which alkaline earth metal carbonate is used as an ingredient of chewing gum?
Answer: CaCO₃

Question 94. What is a fusion mixture?
Answer: A mixture of Na₂CO₃ and K₂CO₃

Question 95. What is the most abundant source of sodium chloride?
Answer: Seawater

Question 96. For which of its chief properties is Plaster of Pariswide used?
Answer: On mixing with water, it forms a plastic mass which sets into a hard mass within 5 to 15 minutes;

Question 97. What is used for making blackboard chalks?
Answer: CaCO₃

Question 98. Which compound is generally used for the detection of CO₂ in the laboratory?
Answer: Lime water [Ca(OH)₂]

Question 99. What is the diagonal relationship? Give one example
Answer:

See ‘General Discussion on s -block elements

Question 100. Which of the alkaline earth metal hydroxides are amphotericin in nature?
Answer:

Beryllium hydroxide [Be(OH)₂] is amphoteric in nature

Question 101. What is hydrolysis?
Answer:

Calcium hydride [CaH₂] is known as hydrolytic

Question 102. Find out the oxidation state of sodium in Na₂O₂.
Answer:

Let the oxidation state of Na be x. The oxidation state of oxygen in the peroxides is -1

2x + 2(-1) = 0; 2x = 2,x= +1.

Question 103. Which two alkaline earth metals cannot be identified by flame test?
Answer:

Beryllium (Be) and magnesium (Mg) cannot be identified by flame test

Question 104. Magnesium occurs in nature largely as MgCO₃but beryllium never occurs as BeCO₃. Explain.
Answer:

The strong polarising power of Be²⁺ ion makes BeCO₃ unstable;

Question 105. Out of Na and Mg which one has a higher second ionization enthalpy? Why?
Answer:

The second ionization enthalpy of Na is higher than that of Mg;

Question 106. The chloride of a metal is soluble in an organic solvent. The chloride can be CaCl₂, NaCl, MgCl₂, BeCl₂
Answer: BeCl₂

Question 107. Why does common salt become wet in the rainy season?
Answer:

Due to the absorption of aerial moisture by deliquescent impurities like MgCl₂, CaCl_2, etc;

NCERT Solutions For Class 11 Chemistry Chapter 10 S Block Elements Fill In The Blanks

Question 1. _____________ has no d-orbital in its valence shell.
Answer: Lithium

Question 2. _____________ reacts with nitrogen to give nitrides.
Answer: Lithium

Question 3. _____________ imparts a golden-yellow color to the flame.
Answer: Sodium

Question 4. Potassium, in reaction with dioxygen, produces _____________
Answer: KO₂

Question 5. The outermost electronic configuration of the radioactive alkali metal is _____________
Answer: 7s¹

Question 6. The bicarbonate salt_____________ of does not exist in solid state.
Answer: Lithium

Question 7. Ionic conductance of Li+ ion in aqueous solution is lowest _____________ is highest
Answer: Hydration

Question 8. _____________ion has maximum polarising power
Answer: Li⁺

Question 9. _____________ is the most abundant alkali metal in Earth’s
Answer: Sodium

Question 10. The basicity of the alkali metal hydroxides _____________ down the group.
Answer: Increases

Question 11._____________ is used as a source of oxygen in submarines, space shuttles, and oxygen masks.
Answer: KO₂

Question 12. The alkali metals combine with mercury to give_____________
Answer: Amalgams

Question 13. The alkali metals exist as_____________ lattices having cordination number 8.
Answer: Body Center cubic

Question 14. Lil _____________ is more soluble than KI in ethanol.
Answer: More

Question 15. K₂CO₃ cannot be produced by the Solvay process because _____________ does not get precipitated in the aqueous solution.
Answer: KHCO₃

Question 16. _____________ and _____________ do not respond to flame test.
Answer: Be,  Mg

Question 17. _____________ ion exhibits maximum does not respond tendency to complexes.
Answer: Be²⁺

Question 18. Only _____________ can displace hydrogen from dilute HNO₃
Answer: Mg

Question 19. Common salt gets wet due to the presence of _____________ as impurity.
Answer: MgCl₂

Question 20. Hydration enthalpy of Mg²⁺ is _____________ Ca²⁺. as than that of
Answer: Greater

Question 21. Hydrolysis of calcium carbide produces _____________
Answer: Acetylene

Question 22. The commercial name of _____________is hydrolith
Answer: CaH₂,

Question 23. BeCO₃ is stable only in an atmosphere of _____________
Answer: CO₂

Question 24. Lime water is a transparent aqueous solution of _____________
Answer: Ca(OH)₂

Question 25. The second ionization enthalpy of the alkaline earth metals is _____________ than their first ionization enthalpy.
Answer: Greater

Question 26. _____________ is used to prepare Grignard reagents
Answer: Greater

Question 27. The melting point of the alkaline earth metals is _____________ than that of alkali metals
Answer: Mg

Question 28. Between Ca and Na, _____________ is used to dehydrate alcohols
Answer: Ca

Question 29. Among the alkaline earth metals, _____________ is abundant in the earth’s crust.
Answer: Ca

Question 30. Temperature of the mixture of _____________  -54°C. Is most and ice is about
Answer: CaCl²⁺