208 + Interview Questions in THE-ALKALI-METALS IN GENERAL AWARENESS Page 2 InterviewSolution

51.	The products obtained on heating `LiNO_(3)` will beA. `LiNO_(2)+O_(2)`B. `Li_(2)O+NO_(2)+O_(2)`C. `Li_(3)N+O_(2)`D. `Li_(2)O+NO+O_(2)`.
Answer» Correct Answer - B `4LiNO_(3)overset(Delta)rarr2Li_(2)O+4NO_(2)+O_(2)`.

Discussion

52.	In the reaction `M + O_(2)rarrMO_(2)` (superoxide) the metal M isA. LiB. NaC. KD. Ba.
Answer» Correct Answer - C Formation of oxides, peroxides and superoxides depend on the size of alkali metal. An atom with larger size produces super oxide. Li forms oxide, Na forms peroxide whereas K forms superoxide.

Discussion

53.	The most dangerous method of preparing hydrogen would be by the action of HCl onA. ZnB. KC. FeD. Al.
Answer» Correct Answer - B K reacts with HCl violently with vigorous evolution of hydrogen that catches fire.

Discussion

54.	Which of the following statements is false for alkali metals ?A. `Li^(+)` is exceptionally smallB. Sodium is amphoteric in natureC. Lithium is the strongest reducing agentD. All alkali metals give blue solution in liquid ammonia.
Answer» Correct Answer - B Sodium is basic in character.

Discussion

55.	A moderately concentrated solution of an alkali metal in `NH_(3)` (pick the odd one out)A. is blue colouredB. is paramagneticC. is a good conductor of electricity and its conductivity increases with increase in temperatureD. is meta stable.
Answer» Correct Answer - C A moderately concentrated solution of an alkali metal in `NH_(3)` is blue coloured, is paramagnetic, is metastable, is a good conductor of electricity showing a metallic conductance (i.e., conductances decreases with increase in temperature).

Discussion

56.	Pick out the false statement :A. The electropositive character of alkali metals decreases with increase in atomic numberB. Lithium is a hard metal nad cannot be cut with a knifeC. Alkali metals are strong reducing agentsD. The electronegativities of all alkali metals remain the same.
Answer» Correct Answer - A

Discussion

57.	Alkali metals never occur free in nature becauseA. they are unstable B. they are very reactive chemicallyC. their compounds with other elements are very stableD. none of these.
Answer» Correct Answer - B

Discussion

58.	Sodium metal is kept underA. Kerosene oilB. AlcoholC. WaterD. Acids.
Answer» Correct Answer - A Alkali metal are highly reactive so much so that they even react on exposure to air. Hence to avoid this reactivity they except Lithium are stored in kerosene oil

Discussion

59.	In a period, the electronegativity and ionization energy of alkali metal isA. maximumB. minimumC. intermediateD. equal to that of halogens.
Answer» Correct Answer - C Lithium metals have a large size.

Discussion

60.	Alkali metals never occur free in nature becauseA. they are unstableB. they are very reactive chemicallyC. their compounds with other elements are very stableD. none of these.
Answer» Correct Answer - B

Discussion

61.	The alkali metals are chemically similar becauseA. their valence shell electrons are equally energeticB. their outermost electrons have the same principal quantum numberC. their valence shell electronic configuration is sameD. their atomicity is one.
Answer» Correct Answer - C Chemical properties depend upon valence shell electronic configuration.

Discussion

62.	Alkali metals never occur free in nature becauseA. they are unstableB. Their chemical activity is very highC. Their compounds with other elements are highly stableD. None of these.
Answer» Correct Answer - B They are chemically very reactive.

Discussion

63.	When sodium is dissolved in pure liquid ammonia along with `H_(2)`, the other product isA. SodiumB. Sodium amideC. Sodium ammoniateD. Sodium tetra-ammoniate.
Answer» Correct Answer - B `Na+NH_(3)rarrNaNH_(2)+(1)/(2)H_(2)`

Discussion

64.	Which one of the elements reacts directly with nitrogen to form nitride ?A. LiB. BaC. KD. Rb.
Answer» Correct Answer - A The only alkali metal which react with `N_(2)` directly is Li. `6Li + N_(2) rarr2Li_(3)N`

Discussion

65.	When sodium is treated with sufficient oxygen/air, the product obtained isA. `Na_(2)O`B. `Na_(2)O_(2)`C. `NaO_(2)`D. `NaO`.
Answer» Correct Answer - B `2Na+O_(2)overset(Delta)rarrunderset("Sod. peroxide")(Na_(2)O_(2))`

Discussion

66.	The composition of common baking powder isA. Starch, sodium carbonate, acetic acidB. Sodium bicarbonate, hydrochloric acidC. Starch, sodium bicarbonate, citric acidD. Starch, sodium bicarbonate, potassium hydrogen tartrate.
Answer» Correct Answer - D Starch+sodium bicarbonate+potassium hydrogen tartarate.

Discussion

67.	Potassium is kept inA. WaterB. AmmoniaC. AlcoholD. Kerosene
Answer» Correct Answer - D Potassium is kept in kerosene.

Discussion

68.	The ionic conductance of the following cations in a given concentration is in the orderA. `Li^(+) lt Na^(+)ltK^(+)ltRb^(+)`B. `Li^(+) gt Na^(+)gtK^(+)gtRb^(+)`C. `Li^(+) gt Na^(+)ltK^(+)ltRb^(+)`D. `Li^(+) = Na^(+)ltK^(+)ltRb^(+)`.
Answer» Correct Answer - A `Li^(+)` cation being smallest of all is heavily hydrated and `Rb^(+)` being biggest is poorly hydrated. Hence ionic conductance of `Li^(+)` is lowest and that of `Rb^(+)` is highest.

Discussion

69.	Identify the correct statementA. Elemental sodium can be prepared and isolated by electrolysing an aqueous solution of NaCl.B. Elemental Na is a strong oxidising agentC. Elemental Na is insoluble in `NH_(3)`D. Elemental Na is easily oxidised.
Answer» Correct Answer - D Elemental Na is easily oxidised. It is a strong reducing agent. It is soluble in `NH_(3)`. It is prepared by electrolysis of fused NaCl.

Discussion

70.	Alcohol dissolvesA. KClB. NaClC. LiClD. RbCl.
Answer» Correct Answer - C

Discussion

71.	The oxide of which metal is most stable to heat :A. AgB. KC. HgD. none of these.
Answer» Correct Answer - B

Discussion

72.	Which of the following statements is false regarding saline hydrides?A. In the molten state they conduct electricityB. They dissolve in water giving off hydrogenC. They are used as reducing agentsD. They are covalent in nature.
Answer» Correct Answer - D Saline hydrides are ionic in nature.

Discussion

73.	Amongest the alkali metal hydrides, the most stable one isA. LiHB. NaHC. KHD. RbH.
Answer» Correct Answer - A LiH

Discussion

74.	Microcosmic salt isA. `Na_(2)HPO_(4).2H_(2)O`B. `(NH_(4)) _(2)HPO_(4).2H_(2)O`C. `Na(NH_(4))HPO_(4).4H_(2)O`D. None of the above.
Answer» Correct Answer - C Microcosmic salt is `Na(NH_(4))HPO_(4).4H_(2)O`

Discussion

75.	LiOH isA. a weak baseB. a strong baseC. an amphoteric compoundD. an acid compound.
Answer» Correct Answer - A LiOH is a weak base because of strong `M-OH` bond.

Discussion

76.	`LiNO_(3)overset("heat")rarr`A. `O_(2)`B. `NO_(2)`C. `O_(2)+NO_(2)`D. none of these.
Answer» Correct Answer - C `4LiNO_(3)overset(Delta)rarr2Li_(2)O+4NO_(2)+O_(2)`

Discussion

77.	Which one of the following has highest electropositive character ?A. CuB. CsC. BaD. Cr.
Answer» Correct Answer - B Out of the given four elements Cs is most electropositive.

Discussion

78.	Which of the following compound is most stable ?A. LiFB. LiClC. LiBrD. LiI.
Answer» Correct Answer - A Because of the small size of Li, LiF has highest lattice enthalpy and hence most stable.

Discussion

79.	Main process for the manufacture of `Na_(3)CO_(3)` isA. Castner processB. Solvay processC. Down processD. Nelson process.
Answer» Correct Answer - B `Na_(2)CO_(3)` is mainly manufactured by Solvay process.

Discussion

80.	Which of the following sets can be called isoelectronic species ?A. `Na^(+), Mg^(+)`B. `Na, Mg^(+)`C. Na, MgD. Na, `Mg^(+)`
Answer» Correct Answer - B Na : `1s^(2)2s^(2)2p^(6)3s^(1)` `Mg^(+) : 1s^(2)2s^(2)2p^(6)3s^(1)` are isoelectronic species.

Discussion

81.	Which of the following is known as fusion mixture ?A. Mixture of `Na_(2)CO_(3) + NaHCO_(3)`B. `Na_(2)CO_(3).10H_(2)O`C. Mixture of `K_(2)CO_(3) + Na_(2)CO_(3)`D. `NaHCO_(3)`.
Answer» Correct Answer - C Fusion mixture is `Na_(2)CO_(3) + K_(2)CO_(3)`.

Discussion

82.	Which of the following statements is false for alkali metals ?A. Lithium is the strongest reducing agentB. Sodium is amphoteric in natureC. `Li^(+)` is exceptionally smallD. All alkali metals give blue solution in liquid ammonia.
Answer» Correct Answer - B Oxides of sodium are distinctly basic and as such have no amphoteric character.

Discussion

83.	NaCl crystals consist ofA. NaCl moleculesB. Na and Cl atomsC. `Na^(+)` and `Cl^(+)` ionsD. `Na^(-)` and `Cl^(+)` ions.
Answer» Correct Answer - C NaCl crystal consists of `Na^(+)` and `Cl^(-)` ions.

Discussion

84.	Which of the following does not liberate `O_(2)` in Bunsen burner ?A. `MgO`B. `NaNO_(3)`C. `Pb_(3)O_(4)`D. `KClO_(3)`
Answer» Correct Answer - A Magnesium oxide (MgO) on heating does not produce `O_(2)` `2NaNO_(3)overset(Delta)rarr2NaNO_(2)+O_(2)` `2Pb_(3)O_(4)overset(Delta)rarr6PbO + O_(2)` `2KClO_(3)overset(Delta)rarr2KCl+3O_(2)`

Discussion

85.	In electrolysis of `NaCl` when `Pt` electrode is taken `H_(2)` is liberated at cathode while `Hg` cathode it forms sodium amalgam becauseA. Hg is more inert than PtB. More voltage is required to reduce `H^(+)` at Hg than at PtC. Na is dissolved in Hg while it does not dissolve in PtD. Concentration of `H^(+)` ions is larger when Pt electrode is taken.
Answer» Correct Answer - B More voltage is required to reduce `H^(+)` at Hg-cathode than at Pt-cathode.

Discussion

86.	Alkali metal(s) which can be produced by metal displacement method is (are)A. LiB. KC. RbD. Na.
Answer» Correct Answer - A::B::C Only Na can not be produced by metal displacement method. Sodium is produced by the electrolysis of its fused chlorides (NaCl).

Discussion

87.	Which of the following alkali metals form complex hydrides?A. LiB. KC. NaD. Rb.
Answer» Correct Answer - A::C Li and Na form complex hydrides `underset("Lithium aluminium hydride ")(LiAlH_(4))underset("Sodium borohydride")(NaBH_(4))`

Discussion

88.	The statement(s) not correct about lithium is (are)A. Lithium is least reactive of all alkali metals.B. It is the weakest reducing agent among all alkali metalsC. It forms no acetylides with acetylene.D. `LiHCO_(3)` is a white crystalline solid.
Answer» Correct Answer - B::D Lithium is the strongest reducing agent among the alkali metals. `LiHCO_(3)` does not exist in solid state.

Discussion

89.	Aqueous solution of KI dissolves `I_(2)` to form `KI_(3)`. Which of the following statements is (are) true ?A. The solution contains `K^(3+)` and `I^(-)` ions.B. The solution contains `K^(+)` and `I_(3)^(-)` ions.C. The solution is violet in colour.D. In `KI_(3), I_(2)` behaves as Lewis acid and `I^(-)` as Lewis base.
Answer» Correct Answer - B::C::D `KI(aq)+I_(2)(s)rarrKI_(3)(aq)+K^(+)(aq) +I_(3)^(-)(aq)` In polyhalide ion `I_(3)^(-)`, `I^(-)` behaves as a Lewis base and `I_(2)` as Lewis acid. `I_(3)^(-)` (aq) are violet coloured.

Discussion

90.	The reactivity of the alkali metal sodium with water, is made use ofA. in drying of alcoholsB. in drying of benzeneC. in drying of ammonia solutionD. as a general drying agent.
Answer» Correct Answer - B Sodium metal react with alcohols, it reacts as well as dissolve in `NH_(3)`. Sodium is used to dry benzene.

Discussion

91.	Considering greater polarization in LiCl compared to that in NaCl, which of the following statements you would expect to be wrong ?A. LiCl has lower melting point than NaClB. LiCl dissolves more in organic solvents than NaClC. LiCl will ionize in water more than NaClD. Fused LiCl would be less conducting than fused NaCl.
Answer» Correct Answer - D LiCl is a covalent compound so it will ionize less in water.

Discussion

92.	Strongest bond is betweenA. CsFB. NaClC. Both (A) and (B)D. None of the above.
Answer» Correct Answer - A Ionic bond is strongest when the difference in electronegativities is maximum. Cs is more electropositive than Na and F is more electronegative than Cl. Therefore, bond in CsF will have more ionic character than NaCl and the bond in CsF will be stronger than in NaCl.

Discussion

93.	Baking soda isA. `NaHCO_(3)`B. `NaHCO_(3).6H_(2)O`C. `Na_(2)CO_(3)`D. `Na_(2)CO_(3).10H_(2)O`.
Answer» Correct Answer - A Baking soda is `NaHCO_(3)`

Discussion

94.	The strongest base among the following will beA. LiOHB. NaOHC. KOHD. RbOH.
Answer» Correct Answer - D The strength depends on the strength of M-OH bond which depends on the size of alkali metal. Larger the size smaller is the strength.

Discussion

95.	When washing soda is heated.A. CO is releasedB. `CO + CO_(2)` is releasedC. `CO_(2)` is releasedD. Water vapour is released.
Answer» Correct Answer - D `Na_(2)CO_(3).10H_(2)Ounderset(-9H_(2)O)overset(Delta)rarrNa_(2)CO_(3).H_(2)OrarrNa_(2)CO_(3)+H_(2)Ouarr`

Discussion

96.	Smallest among these species isA. HydrogenB. HeliumC. LithiumD. Lithion ion.
Answer» Correct Answer - A Hydrogen is the smallest.

Discussion

97.	Which one of the following atoms will have the smallest size ?A. MgB. NaC. BeD. Li.
Answer» Correct Answer - C Atomic sizes are in the order : `Be(112 p m)ltLi(152 p m ) lt Mg (160 p m) lt Na(186 p m)`

Discussion

98.	The yellow light used for illumination is fromA. Mercury vapour lampB. Sodium vapour lampC. Neon gas lampD. None of these.
Answer» Correct Answer - B Sodium vapour lamp.

Discussion

99.	Chemical name of soda ash isA. sodium carbonateB. Sodium bicarbonateC. Sodium hydroxideD. None of these.
Answer» Correct Answer - A `Na_(2)CO_(3)` (anhyd.) is called soda ash. Sodium bicarbonate is called baking soda. Sodium hydroxide is called caustic soda.

Discussion

100.	Which of the following reacts with water at a high rate ?A. LiB. KC. NaD. Rb.
Answer» Correct Answer - D Out of Li, Na, K and Rb, Rb reacts fastest with water. The rate of reaction increases down the group.

Discussion

Explore topic-wise InterviewSolutions in .

The products obtained on heating `LiNO_(3)` will beA. `LiNO_(2)+O_(2)`B. `Li_(2)O+NO_(2)+O_(2)`C. `Li_(3)N+O_(2)`D. `Li_(2)O+NO+O_(2)`.

In the reaction `M + O_(2)rarrMO_(2)` (superoxide) the metal M isA. LiB. NaC. KD. Ba.

The most dangerous method of preparing hydrogen would be by the action of HCl onA. ZnB. KC. FeD. Al.

Which of the following statements is false for alkali metals ?A. `Li^(+)` is exceptionally smallB. Sodium is amphoteric in natureC. Lithium is the strongest reducing agentD. All alkali metals give blue solution in liquid ammonia.

A moderately concentrated solution of an alkali metal in `NH_(3)` (pick the odd one out)A. is blue colouredB. is paramagneticC. is a good conductor of electricity and its conductivity increases with increase in temperatureD. is meta stable.

Pick out the false statement :A. The electropositive character of alkali metals decreases with increase in atomic numberB. Lithium is a hard metal nad cannot be cut with a knifeC. Alkali metals are strong reducing agentsD. The electronegativities of all alkali metals remain the same.

Alkali metals never occur free in nature becauseA. they are unstable B. they are very reactive chemicallyC. their compounds with other elements are very stableD. none of these.

Sodium metal is kept underA. Kerosene oilB. AlcoholC. WaterD. Acids.

In a period, the electronegativity and ionization energy of alkali metal isA. maximumB. minimumC. intermediateD. equal to that of halogens.

Alkali metals never occur free in nature becauseA. they are unstableB. they are very reactive chemicallyC. their compounds with other elements are very stableD. none of these.

The alkali metals are chemically similar becauseA. their valence shell electrons are equally energeticB. their outermost electrons have the same principal quantum numberC. their valence shell electronic configuration is sameD. their atomicity is one.

Alkali metals never occur free in nature becauseA. they are unstableB. Their chemical activity is very highC. Their compounds with other elements are highly stableD. None of these.

When sodium is dissolved in pure liquid ammonia along with `H_(2)`, the other product isA. SodiumB. Sodium amideC. Sodium ammoniateD. Sodium tetra-ammoniate.

Which one of the elements reacts directly with nitrogen to form nitride ?A. LiB. BaC. KD. Rb.

When sodium is treated with sufficient oxygen/air, the product obtained isA. `Na_(2)O`B. `Na_(2)O_(2)`C. `NaO_(2)`D. `NaO`.

The composition of common baking powder isA. Starch, sodium carbonate, acetic acidB. Sodium bicarbonate, hydrochloric acidC. Starch, sodium bicarbonate, citric acidD. Starch, sodium bicarbonate, potassium hydrogen tartrate.

Potassium is kept inA. WaterB. AmmoniaC. AlcoholD. Kerosene

The ionic conductance of the following cations in a given concentration is in the orderA. `Li^(+) lt Na^(+)ltK^(+)ltRb^(+)`B. `Li^(+) gt Na^(+)gtK^(+)gtRb^(+)`C. `Li^(+) gt Na^(+)ltK^(+)ltRb^(+)`D. `Li^(+) = Na^(+)ltK^(+)ltRb^(+)`.

Identify the correct statementA. Elemental sodium can be prepared and isolated by electrolysing an aqueous solution of NaCl.B. Elemental Na is a strong oxidising agentC. Elemental Na is insoluble in `NH_(3)`D. Elemental Na is easily oxidised.

Alcohol dissolvesA. KClB. NaClC. LiClD. RbCl.

The oxide of which metal is most stable to heat :A. AgB. KC. HgD. none of these.

Which of the following statements is false regarding saline hydrides?A. In the molten state they conduct electricityB. They dissolve in water giving off hydrogenC. They are used as reducing agentsD. They are covalent in nature.

Amongest the alkali metal hydrides, the most stable one isA. LiHB. NaHC. KHD. RbH.

Microcosmic salt isA. `Na_(2)HPO_(4).2H_(2)O`B. `(NH_(4)) _(2)HPO_(4).2H_(2)O`C. `Na(NH_(4))HPO_(4).4H_(2)O`D. None of the above.

LiOH isA. a weak baseB. a strong baseC. an amphoteric compoundD. an acid compound.

`LiNO_(3)overset("heat")rarr`A. `O_(2)`B. `NO_(2)`C. `O_(2)+NO_(2)`D. none of these.

Which one of the following has highest electropositive character ?A. CuB. CsC. BaD. Cr.

Which of the following compound is most stable ?A. LiFB. LiClC. LiBrD. LiI.

Main process for the manufacture of `Na_(3)CO_(3)` isA. Castner processB. Solvay processC. Down processD. Nelson process.

Which of the following sets can be called isoelectronic species ?A. `Na^(+), Mg^(+)`B. `Na, Mg^(+)`C. Na, MgD. Na, `Mg^(+)`

Which of the following is known as fusion mixture ?A. Mixture of `Na_(2)CO_(3) + NaHCO_(3)`B. `Na_(2)CO_(3).10H_(2)O`C. Mixture of `K_(2)CO_(3) + Na_(2)CO_(3)`D. `NaHCO_(3)`.

Which of the following statements is false for alkali metals ?A. Lithium is the strongest reducing agentB. Sodium is amphoteric in natureC. `Li^(+)` is exceptionally smallD. All alkali metals give blue solution in liquid ammonia.

NaCl crystals consist ofA. NaCl moleculesB. Na and Cl atomsC. `Na^(+)` and `Cl^(+)` ionsD. `Na^(-)` and `Cl^(+)` ions.

Which of the following does not liberate `O_(2)` in Bunsen burner ?A. `MgO`B. `NaNO_(3)`C. `Pb_(3)O_(4)`D. `KClO_(3)`

Alkali metal(s) which can be produced by metal displacement method is (are)A. LiB. KC. RbD. Na.

Which of the following alkali metals form complex hydrides?A. LiB. KC. NaD. Rb.

The statement(s) not correct about lithium is (are)A. Lithium is least reactive of all alkali metals.B. It is the weakest reducing agent among all alkali metalsC. It forms no acetylides with acetylene.D. `LiHCO_(3)` is a white crystalline solid.

The reactivity of the alkali metal sodium with water, is made use ofA. in drying of alcoholsB. in drying of benzeneC. in drying of ammonia solutionD. as a general drying agent.

Strongest bond is betweenA. CsFB. NaClC. Both (A) and (B)D. None of the above.

Baking soda isA. `NaHCO_(3)`B. `NaHCO_(3).6H_(2)O`C. `Na_(2)CO_(3)`D. `Na_(2)CO_(3).10H_(2)O`.

The strongest base among the following will beA. LiOHB. NaOHC. KOHD. RbOH.

When washing soda is heated.A. CO is releasedB. `CO + CO_(2)` is releasedC. `CO_(2)` is releasedD. Water vapour is released.

Smallest among these species isA. HydrogenB. HeliumC. LithiumD. Lithion ion.

Which one of the following atoms will have the smallest size ?A. MgB. NaC. BeD. Li.

The yellow light used for illumination is fromA. Mercury vapour lampB. Sodium vapour lampC. Neon gas lampD. None of these.

Chemical name of soda ash isA. sodium carbonateB. Sodium bicarbonateC. Sodium hydroxideD. None of these.

Which of the following reacts with water at a high rate ?A. LiB. KC. NaD. Rb.