208 + Interview Questions in THE-ALKALI-METALS IN GENERAL AWARENESS Page 1 InterviewSolution

1.	Among `KO_(2)`, `AlO_(2)^(-)`, `BaO_(2)` and `NO_(2)^(+)`, unpaired electrons is present inA. `NO_(2)^(+)` and `BaO_(2)`B. `KO_(2)` and `AlO_(2)^(-)`C. `KO_(2)` onlyD. `BaO_(2)` only.
Answer» Correct Answer - C A superoxide ion `O_(2)^(-)` (in `KO_(2)`) contains unpaired electron.

Discussion

2.	A combustible gas is liberated when caustic soda solution is heated withA. SB. `NH_(4)Cl`C. `I_(2)`D. Zn.
Answer» Correct Answer - D `Zn + 2NaOH overset(Delta)rarrunderset("Sod. zincate")(Na_(2)ZnO_(2))+H_(2)` `H_(2)` is a combustible gas.

Discussion

3.	A combustible gas is liberated when caustic soda solution is heated withA. `NH_(4)Cl`B. `I_(2)`C. ZnD. S.
Answer» Correct Answer - C `Zn + 2NaOH rarrNa_(2)ZnO_(2)+underset("Inflammable gas")(H_(2))`

Discussion

4.	When a substance a reacts with water, it produces a combustible gas B and a solution of substance C in water. When another substances D reacts with this solution of C . It also produce gas B on reaction with dilute sulphuric acid at room temperature . A imparts a deep golden yellow colour to the smokless flame of bunsen flame A,B , C and D are respectivelyA. Na, `H_(2)`, NaOH and ZnB. K, `H_(2)`, KOH and AlC. Ca, `H_(2)`, `Ca(OH)_(2)` and SnD. `CaC_(2), C_(2)H_(2)`, `Ca(OH)_(2)` and Fe.
Answer» Correct Answer - A `{:(2Na+2H_(2)Orarr,2NaOH,+H_(2),),((A),(C ),(B),),(2NaOH+Znrarr,Na_(2)ZnO_(2),+H_(2),),((C )" (D)",,(B),):}` Na(A) imparts a golden yellow colour to the flame.

Discussion

5.	An aqueous solution of sodium sulphate is electrolysed using inert electrodes. The products at the cathode and anode are respectivelyA. `H_(2), O_(2)`B. `O_(2), H_(2)`C. `O_(2), Na`D. `O_(2), SO_(2)`.
Answer» Correct Answer - A Electrolysis of a solution of `Na_(2)SO_(4)` with Pt (inert) electrodes gives `H_(2)` (at cathode) and `O_(2)` (at anode).

Discussion

6.	The metallic lustre exhibited by sodium is explained byA. Diffusion of sodium ionsB. Oscillation of loose electronsC. Excitation of free protonsD. Existence of body centred cubic lattice.
Answer» Correct Answer - B Metallic lustre of sodium is due to oscillation of loose electrons.

Discussion

7.	Assertion (A) The reaction LiI + KF `rarr` LiF + KI proceed in the direction indicated. Reasons (A) Fluorine, being more reactive can easily replace iodine.
Answer» Correct Answer - B Reason. Large cation stabilises larger anion.

Discussion

8.	Sodium peroxide which is yellow solid, when exposed to air becomes white due to the formation ofA. `H_(2)O_(2)`B. `Na_(2)O`C. `Na_(2)O + O_(3)`D. NaOH and `Na_(2)CO_(3)`
Answer» Correct Answer - D `CaCO_(3)overset(Delta)rarrunderset(("basic"))(CaO)+underset(("acidic"))(CO_(2))`

Discussion

9.	Which of the following carbonates is least soluble in water ?A. `CaCO_(3)`B. `NaHCO_(3)`C. `Na_(2)SO_(4)`D. `KHCO_(3)`.
Answer» Correct Answer - A It has high lattice energy.

Discussion

10.	Which one of the alkali metals forms only the normal oxide, `M_(2)O`, on heating in air ?A. KB. LiC. NaD. Rb.
Answer» Correct Answer - C Lithium (Li) is the alkali metal which forms only normal oxide. `Li_(2)O` when heated in air. `2Li + 1//2O_(2) rarrLi_(2)O`

Discussion

11.	Which of the following alkali metal carbonates gives `CO_(2)` on heating as well as on treating with acids ?A. `Na_(2)CO_(3)`B. `K_(2)CO_(3)`C. `Rb_(2)CO_(3)`D. `Li_(2)CO_(3)`.
Answer» Correct Answer - D `Li_(2)CO_(3)rarrLi_(2)O+CO_(2)` and `Li_(2)CO_(3)+2HClrarr2LiCl +CO_(2)+H_(2)O`

Discussion

12.	Which of the following alkali metals form only, the normal oxide, `M_(2)O` on heating in air ? (where M is the alkali metal)A. RbB. KC. LiD. Na.
Answer» Correct Answer - C Li forms only the normal oxide, `Li_(2)O`

Discussion

13.	The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:A. `Rb^(+)ltK^(+)ltNa^(+) ltLi^(+)`B. `K^(+)ltNa^(+)ltRb^(+) ltLi^(+)`C. `Na^(+) lt Li^(+)lt K^(+)lt Rb^(+)`D. `Li^(+) lt K^(+) lt Na^(+) lt Rb^(+)`
Answer» Correct Answer - C Ease of adsorption of the hydrated alkali metal ions on an ion exchange resins decreases as the size of the alkali metal ions increases. Since, the order of size of alkali metal ions `Li^(+) lt Na^(+) lt K^(+) lt Rb^(+)` the ease of adsorption follows the order `Rb^(+) lt K^(+) lt Na ^(+) lt Li^(+)`

Discussion

14.	The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:A. `Li^(+) lt Na^(+) lt K^(+)lt Rb^(+)`B. `Rb^(+) lt K^(+) lt Na^(+) lt Li^(+)`C. `K^(+) lt Na^(+) lt Rb^(+) lt Li^(+)`D. `Na^(+) lt Li^(+) lt K^(+) lt Rb^(+)`.
Answer» Correct Answer - A Larger the size of the hydrated cation, smaller is the ease of adsorption. Thus ease of adsorption increase in the order : `Li^(+) lt Na^(+) lt K^(+) lt Rb^(+)`

Discussion

15.	Which of the following alkali metal ions in aqueous solution is the best conductor of electricity ?A. `Li^(+)`B. `Na^(+)`C. `K^(+)`D. `Cs^(+)`
Answer» Correct Answer - D Extent of hydration of ions decreases on moving down the group from top to bottom, `Cs^(+)` undergoes least hydration and hence has highest ionic mobility.

Discussion

16.	Among alkali metal salts, the lithium salts are the poore conductors of electricity in aqueous solution because ofA. Easy diffusion of `Li^(+)` ions to polarize water moleculesB. Lowest charge to radius ratioC. Lowest charge to radius ratioD. Higher degree of hydration of `Li^(+)` ions
Answer» Correct Answer - D `Li^(+)` ions due to high charge density, are hydrated to maximum extent, in water.

Discussion

17.	Among the alkali metals, the lithium salts are the poorest conductors of electricity in aqueous solution because ofA. easy diffusion of Li ionsB. lowest ability to polarise water moleculeC. lowest charge to radius ration of LiD. highest degree of hydration.
Answer» Correct Answer - D Highest degree of hydration.

Discussion

18.	The correct order of mobility of the alkali metal ions in aqueous solution isA. `Rb^(+)gtK^(+)gtNa^(+)gtLi^(+)`B. `Li^(+)gtNa^(+)gtK^(+)gtRb^(+)`C. `Na^(+)gtK^(+)gtRb^(+)gtLi^(+)`D. `K^(+)gtRb^(+)gtNa^(+)gtLi^(+)`.
Answer» Correct Answer - A On the basis of explanation of ionic mobility extent of an ion given in Q. 24, the mobility of alkali metal ions in aqueous solution follows the order. `Rb^(+) gt K^(+) gt Na^(+) gt Li^(+)`.

Discussion

19.	Which of the following is not correct ?A. `KI + I_(2) rarr KI_(3)`B. `KBr + ICI rarr K[BrICl]`C. `KF + BrF_(3) rarr K[BrF_(4)]`D. `KF + F_(2) rarr KF_(3)`.
Answer» Correct Answer - D Due to absence of d-orbitals, `F^(-)` does not combine with `F_(2)` to form `F_(3)^(-)` polyhalide ion.

Discussion

20.	Which of the following alkali metal ions in aqueous solution is the best conductor of electricity ?A. `Li^(+)`B. `Na^(+)`C. `Cs^(+)`D. `K^(+)`
Answer» Correct Answer - C The ion which is least hydrated shall have a greater molarity

Discussion

21.	The alkali metal used in photoelectric cell isA. NaB. CsC. RbD. Fr.
Answer» Correct Answer - A The metal with low I.E. is used in photoelectric cells.

Discussion

22.	Rb[IC`I_(2)`] on heating givesA. `RbCl + ICI`B. `2Rb + 2Cl_(2) + I_(2)` (from two molecules)C. `RbI + Cl_(2)`D. `2Rb[ICI] + Cl_(2)` (from two molecules).
Answer» Correct Answer - A Alkali metal halides combine with interhalogen compounds forming polyhalides. On heating the reverse reaction occurs. `Rb[ICl_(2)]overset(Delta)rarrRbCl+ICl`

Discussion

23.	The correct arrangement of increasing order of atomic radius among Na, K, Mg, Rb isA. Na `gt` K `gt` Mg `gt` RbB. K `gt` Na `gt` Mg `gt` RbC. Na `gt` Mg `gt` K `gt` RbD. Mg `gt` Na `gt` K `gt` Rb.
Answer» Correct Answer - D The increasing order of atomic radius (metallic) is Mg(160 pm) `lt` Na (180 pm) `lt` K (227 pm) `lt` Rb (248 pm)

Discussion

24.	Which of the following are arranged in correct increasing order of solubilities ?A. `CaCO_(3) gt KHCO_(3) gt NaHCO_(3)`B. `NaHCO_(3) gt NaHCO_(3) gt CaCO_(3)`C. `KHCO_(3) gt NaHCO_(3) gt CaCO_(3)`D. `CaCO_(3) lt NaHCO_(3) gt KHCO_(3)`
Answer» Correct Answer - D Correct order of solubilities in water `CaCO_(3) lt NaHCO_(3) lt KHCO_(3)`

Discussion

25.	Which of the following oxides is formed when potassium metal is burnt in excess air ?A. `K_(2)O`B. KOC. `KO_(2)`D. `K_(2)O_(2)`.
Answer» Correct Answer - C When potassium is burnt in excess of air, potassium superoxide is formed. `K +O_(2) rarrKO_(2)`

Discussion

26.	Which of the following has the highest solubility product ?A. KOHB. CsOHC. LiOHD. RbOH.
Answer» Correct Answer - B Solubilities of alkali metal hydroxides increase down the group `LiOH lt KOH lt RbOH lt CsOH`

Discussion

27.	Which one of the following has minimum value of cation/anion ratio ?A. NaClB. KClC. `MgCl_(2)`D. `CaF_(2)`.
Answer» Correct Answer - C Size of cation `Mg^(2+)(72 p m) lt Ca^(2+)(100 p m)ltNa^(+) (102 p m) lt K^(+) (138 p m)` Size of anion. `F^(-)(133 p m) lt Cl^(-)(184p m)` Size of cation/anion will be minimum when size of cation is minimum and size of anion is maximum (i.e. `Mg^(2+)//Cl^(-)`) i.e., in `MgCl_(2)`.

Discussion

28.	Which of the following electronic configuration corresponds to an element with the lowest ionization energy ?A. `1s^(2)2s^(2)2p^(3)`B. `1s^(2)2s^(2)2p^(5)`C. `Is^(2)s^(2)2p^(6)`D. `Is^(2)2s^(2)2p^(6)3s^(1)`
Answer» Correct Answer - D Alkali metals have low ionisation energies. Outer electronic configurations of alkali metals are `(n-1)s^(2)p^(6),ns^(1)`.

Discussion

29.	Which of the following compounds has the lowest anion to cation size ratio ?A. LiFB. NaFC. CsID. CsF.
Answer» Correct Answer - D Size of cations `Li^(+)ltNa^(+)ltCs^(+)` Sizes of anions `F^(-) lt I^(-)` Lowest anion/cation is `F^(-)//Cs^(+)` i.e., in case of CsF.

Discussion

30.	In Castner-Kellner cell, sodium hydroxide is formed in the central compartment.A. GoldB. SilverC. IronD. Mercury.
Answer» Correct Answer - C

Discussion

31.	Which of the following is not correct ?A. Iodine oxidises sodium thiosulphate to sodium tetrathionateB. Sodium thiosulphate is soluble in waterC. Ozone is used to identify the presence of unsaturation in alkeneD. Sodium thiosulphate reacts with iodine to form sodium sulphate.
Answer» Correct Answer - D `I_(2)` reacts with `Na_(2)S_(2)O_(3)` to give sod tetrathionate `I_(2)+2Na_(2)S_(2)O_(3)rarrNa_(2)S_(4)O_(6)+2NaI` In this reaction `I_(2)` acts as an oxidising agent.

Discussion

32.	An aqueous solution of sodium carbonate is alkaline because sodium carbonate is a salt ofA. Weak acid and weak baseB. Strong acid and weak baseC. Weak acid and strong baseD. Strong acid and strong base.
Answer» Correct Answer - C An aqueous solution of `Na_(2)CO_(3)` is basic because it is a salt of weak acid `(H_(2)CO_(3))` and strong base (NaOH).

Discussion

33.	The carbonate that will not decompose on heating isA. `Na_(2)CO_(3)`B. `CaCO_(3)`C. `BaCO_(3)`D. `SrCO_(3)`
Answer» Correct Answer - A Alkali metal carbonates (i.e., `Na_(2)CO_(3), K_(2)CO_(3)`, etc.) except `Li_(2)CO_(3)` do not decompose on heating.

Discussion

34.	The alkali metal which can be obtained by reduction of its carbonate with carbon isA. NaB. LiC. RbD. None.
Answer» Correct Answer - C Rubidium can even be obtained by reduction of its carbonate with C. `Rb_(2)CO_(3)+2Coverset(Delta)rarr2Rbuarr+3COuarr`

Discussion

35.	In the replacement reaction `rarrC-I+MF rarr rarr C-F+MI` The reaction will be most favourable if `M` happens to beA. NaB. KC. RbD. Li.
Answer» Correct Answer - C `3^(@)` Alkyl halides undergo `S_(N^(1))` reaction in which a nucleophiles attacks a carbocation. Thus more the ionic character of the M-F bond, more favourable will be the replacement reaction. Since amongest Li, Na, K and Rb, Rb has the largest size, therefore Rb-F bond has the highest ionic character and therefore, option (C ) is correct.

Discussion

36.	Alkali metals have negative reduction potential and hence they behave asA. oxidising agentsB. Lewis baseC. reducing agentsD. electrolytes.
Answer» Correct Answer - C Elements having `-ve E^(@)` act as a reducing agents.

Discussion

37.	Which of the following is a wrong statements ?A. Potassium reacts vigorously with water and gives alkaline solution with the liberation of hydrogen gasB. The alkali metal hydroxides are strong bases because they ionize completely in dilute aqueous solutionsC. Potassium carbonate cannot be prepared by Solvay processD. Lithium chloride is insoluble in alcohol but soluble in water.
Answer» Correct Answer - D Actually LiCl is a covalent compound and is soluble in alcohol.

Discussion

38.	Which of the following is the correct order of chemical reactivity with water according to electrochemical series ?A. `KgtMggtZngtCu`B. `KgtMggtCugtZn`C. `Cu gt Zn gt K gt Mg`D. `Mg gt K gt Cu gt Zn`.
Answer» Correct Answer - A Reactivity of metals depend on I.E. Lowest is the value of I.E. more is the reactivity.

Discussion

39.	On heating sodium metal in a current of dry ammonia, the compound formed isA. Sodium amideB. Sodium azideC. Sodium nitrideD. Sodium hydride.
Answer» Correct Answer - A `Na + NH_(3) rarrunderset("Sodium amide")(NaNH_(2))+H_(2)`

Discussion

40.	On heating sodium metal in a current of ammonia the compound formed isA. Sodium nitrideB. Sodium hydrideC. Sodium amideD. Sodium azide.
Answer» Correct Answer - C `2Na+2NH_(3)rarrunderset("sodamide")(2NaNH_(2))+H_(2)`

Discussion

41.	Electrochemical process (electrolysis of fused salt) is employed to extractA. IronB. MgC. NaD. Both Na and Mg.
Answer» Correct Answer - D Both Na and Mg are extracted by electrolysis process.

Discussion

42.	In the following reaction `NaOH+SrarrA+Na_(2)S+H_(2)O, A`A. `Na_(2)SO_(4)`B. `Na_(2)SO_(3)`C. `Na_(2)S`D. `Na_(2)S_(2)O_(3)`.
Answer» Correct Answer - D `4S+6NaOH rarrNa_(2)S_(2)O_(3)+2Na_(2)S+3H_(2)`

Discussion

43.	The stability of the following alkali metal chlorides follows the order:A. LiCl `gt` KCl `gt` NaCl `gt` CsClB. CsCl `gt` KCl `gt` NaCl `gt` LiClC. NaCl `gt` KCl `gt` LiCl `gt` CsClD. KCl `gt` CsCl `gt` NaCl `gt` LiCl.
Answer» Correct Answer - D Standard enthalpies of formation of alkali metal chlorides, are `DeltaH_(f)^(@) (LiCl) = - 408.8 " kJ mol" ^(-1)` `DeltaH_(f)^(@) (NaCl) = - 411.15 " kJ mol" ^(-1)` `DeltaH_(f)^(@) (CsCl) = - 433 " kJ mol" ^(-1)` `DeltaH_(f)^(@) (KCl) = - 436 " kJ mol" ^(-1)`. More the magnitude of enthalpy of formation (heat evolved when one mole of the compound is formed from the elements) more the stability of the compound. Therefore order of stabilities is `LiCl lt NaCl lt CsCl lt KCl`.

Discussion

44.	In the Solvary process of manufacture of `Na_(2)CO_(3)`. the byproducts areA. `NH_(4)Cl, CaO`B. `CaO, Na_(2)CO_(3)`C. `CaCl_(2), CO_(2), NH_(3)`D. `Na_(2)CO_(3), CO_(2)`.
Answer» Correct Answer - C By products of Solvay process are `CaCl_(2)` (main) `CO_(2)`. Etc.

Discussion

45.	Assertion (A) `Rb_(2)CO_(3)+2Coverset(Delta)rarr2Rb +3CO` Reason (A) Rubidium cannot be produced by reduction with carbon.
Answer» Correct Answer - C Reason. Rubidium is volatile at the reaction temperature and CO has the highest bond energy among all the diatomic molecules.

Discussion

46.	Sodium metal cannot be stored underA. BenzeneB. Kerosene oilC. AlcoholD. Toluene
Answer» Correct Answer - C Sodium reacts with alcohols. `underset("Alcohol")(2Na)+2ROH rarrunderset("Sod.alkoxide")(2RONa)+H_(2)uarr`

Discussion

47.	Sodium conducts electricity becauseA. It is a soft alkali metalB. It has only one electron in the outermost orbitC. It has mobile electronsD. It gives hydrogen with water.
Answer» Correct Answer - C Sodium conducts electricity due to free mobile electrons (metallic conductance).

Discussion

48.	The following are some of the methods commonly employed for the extraction of metals from their ores. Which of the following methods is generally employed for the extraction of sodium ?A. Reduction of an oxide with cokeB. Electrolysis of an aqueous solution of a chlorideC. Electrolysis of a molten chlorideD. Reduction of a chloride with more reactive metal.
Answer» Correct Answer - C Sodium is obtained by the electrolysis of molten sodium chloride.

Discussion

49.	The only oxidation state of alkali metals in their compounds isA. `+ 1`B. `+ 2`C. `- 1`D. zero.
Answer» Correct Answer - A Alkali metals exhibit + oxidation state only.

Discussion

50.	`NaNO_(3)` on heating givesA. `O_(2)`B. `NO_(2)`C. `O_(2)+NO_(2)`D. none of these.
Answer» Correct Answer - A `NaNO_(3)overset(Delta)rarrNaNO_(2)+(1)/(2)O_(2)`

Discussion

Explore topic-wise InterviewSolutions in .

Among `KO_(2)`, `AlO_(2)^(-)`, `BaO_(2)` and `NO_(2)^(+)`, unpaired electrons is present inA. `NO_(2)^(+)` and `BaO_(2)`B. `KO_(2)` and `AlO_(2)^(-)`C. `KO_(2)` onlyD. `BaO_(2)` only.

A combustible gas is liberated when caustic soda solution is heated withA. SB. `NH_(4)Cl`C. `I_(2)`D. Zn.

A combustible gas is liberated when caustic soda solution is heated withA. `NH_(4)Cl`B. `I_(2)`C. ZnD. S.

An aqueous solution of sodium sulphate is electrolysed using inert electrodes. The products at the cathode and anode are respectivelyA. `H_(2), O_(2)`B. `O_(2), H_(2)`C. `O_(2), Na`D. `O_(2), SO_(2)`.

The metallic lustre exhibited by sodium is explained byA. Diffusion of sodium ionsB. Oscillation of loose electronsC. Excitation of free protonsD. Existence of body centred cubic lattice.

Assertion (A) The reaction LiI + KF `rarr` LiF + KI proceed in the direction indicated. Reasons (A) Fluorine, being more reactive can easily replace iodine.

Sodium peroxide which is yellow solid, when exposed to air becomes white due to the formation ofA. `H_(2)O_(2)`B. `Na_(2)O`C. `Na_(2)O + O_(3)`D. NaOH and `Na_(2)CO_(3)`

Which of the following carbonates is least soluble in water ?A. `CaCO_(3)`B. `NaHCO_(3)`C. `Na_(2)SO_(4)`D. `KHCO_(3)`.

Which one of the alkali metals forms only the normal oxide, `M_(2)O`, on heating in air ?A. KB. LiC. NaD. Rb.

Which of the following alkali metal carbonates gives `CO_(2)` on heating as well as on treating with acids ?A. `Na_(2)CO_(3)`B. `K_(2)CO_(3)`C. `Rb_(2)CO_(3)`D. `Li_(2)CO_(3)`.

Which of the following alkali metals form only, the normal oxide, `M_(2)O` on heating in air ? (where M is the alkali metal)A. RbB. KC. LiD. Na.

The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:A. `Rb^(+)ltK^(+)ltNa^(+) ltLi^(+)`B. `K^(+)ltNa^(+)ltRb^(+) ltLi^(+)`C. `Na^(+) lt Li^(+)lt K^(+)lt Rb^(+)`D. `Li^(+) lt K^(+) lt Na^(+) lt Rb^(+)`

The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:A. `Li^(+) lt Na^(+) lt K^(+)lt Rb^(+)`B. `Rb^(+) lt K^(+) lt Na^(+) lt Li^(+)`C. `K^(+) lt Na^(+) lt Rb^(+) lt Li^(+)`D. `Na^(+) lt Li^(+) lt K^(+) lt Rb^(+)`.

Which of the following alkali metal ions in aqueous solution is the best conductor of electricity ?A. `Li^(+)`B. `Na^(+)`C. `K^(+)`D. `Cs^(+)`

Among alkali metal salts, the lithium salts are the poore conductors of electricity in aqueous solution because ofA. Easy diffusion of `Li^(+)` ions to polarize water moleculesB. Lowest charge to radius ratioC. Lowest charge to radius ratioD. Higher degree of hydration of `Li^(+)` ions

Among the alkali metals, the lithium salts are the poorest conductors of electricity in aqueous solution because ofA. easy diffusion of Li ionsB. lowest ability to polarise water moleculeC. lowest charge to radius ration of LiD. highest degree of hydration.

The correct order of mobility of the alkali metal ions in aqueous solution isA. `Rb^(+)gtK^(+)gtNa^(+)gtLi^(+)`B. `Li^(+)gtNa^(+)gtK^(+)gtRb^(+)`C. `Na^(+)gtK^(+)gtRb^(+)gtLi^(+)`D. `K^(+)gtRb^(+)gtNa^(+)gtLi^(+)`.

Which of the following is not correct ?A. `KI + I_(2) rarr KI_(3)`B. `KBr + ICI rarr K[BrICl]`C. `KF + BrF_(3) rarr K[BrF_(4)]`D. `KF + F_(2) rarr KF_(3)`.

Which of the following alkali metal ions in aqueous solution is the best conductor of electricity ?A. `Li^(+)`B. `Na^(+)`C. `Cs^(+)`D. `K^(+)`

The alkali metal used in photoelectric cell isA. NaB. CsC. RbD. Fr.

Rb[IC`I_(2)`] on heating givesA. `RbCl + ICI`B. `2Rb + 2Cl_(2) + I_(2)` (from two molecules)C. `RbI + Cl_(2)`D. `2Rb[ICI] + Cl_(2)` (from two molecules).

The correct arrangement of increasing order of atomic radius among Na, K, Mg, Rb isA. Na `gt` K `gt` Mg `gt` RbB. K `gt` Na `gt` Mg `gt` RbC. Na `gt` Mg `gt` K `gt` RbD. Mg `gt` Na `gt` K `gt` Rb.

Which of the following are arranged in correct increasing order of solubilities ?A. `CaCO_(3) gt KHCO_(3) gt NaHCO_(3)`B. `NaHCO_(3) gt NaHCO_(3) gt CaCO_(3)`C. `KHCO_(3) gt NaHCO_(3) gt CaCO_(3)`D. `CaCO_(3) lt NaHCO_(3) gt KHCO_(3)`

Which of the following oxides is formed when potassium metal is burnt in excess air ?A. `K_(2)O`B. KOC. `KO_(2)`D. `K_(2)O_(2)`.

Which of the following has the highest solubility product ?A. KOHB. CsOHC. LiOHD. RbOH.

Which one of the following has minimum value of cation/anion ratio ?A. NaClB. KClC. `MgCl_(2)`D. `CaF_(2)`.

Which of the following electronic configuration corresponds to an element with the lowest ionization energy ?A. `1s^(2)2s^(2)2p^(3)`B. `1s^(2)2s^(2)2p^(5)`C. `Is^(2)s^(2)2p^(6)`D. `Is^(2)2s^(2)2p^(6)3s^(1)`

Which of the following compounds has the lowest anion to cation size ratio ?A. LiFB. NaFC. CsID. CsF.

In Castner-Kellner cell, sodium hydroxide is formed in the central compartment.A. GoldB. SilverC. IronD. Mercury.

Which of the following is not correct ?A. Iodine oxidises sodium thiosulphate to sodium tetrathionateB. Sodium thiosulphate is soluble in waterC. Ozone is used to identify the presence of unsaturation in alkeneD. Sodium thiosulphate reacts with iodine to form sodium sulphate.

An aqueous solution of sodium carbonate is alkaline because sodium carbonate is a salt ofA. Weak acid and weak baseB. Strong acid and weak baseC. Weak acid and strong baseD. Strong acid and strong base.

The carbonate that will not decompose on heating isA. `Na_(2)CO_(3)`B. `CaCO_(3)`C. `BaCO_(3)`D. `SrCO_(3)`

The alkali metal which can be obtained by reduction of its carbonate with carbon isA. NaB. LiC. RbD. None.

In the replacement reaction `rarrC-I+MF rarr rarr C-F+MI` The reaction will be most favourable if `M` happens to beA. NaB. KC. RbD. Li.

Alkali metals have negative reduction potential and hence they behave asA. oxidising agentsB. Lewis baseC. reducing agentsD. electrolytes.

Which of the following is the correct order of chemical reactivity with water according to electrochemical series ?A. `KgtMggtZngtCu`B. `KgtMggtCugtZn`C. `Cu gt Zn gt K gt Mg`D. `Mg gt K gt Cu gt Zn`.

On heating sodium metal in a current of dry ammonia, the compound formed isA. Sodium amideB. Sodium azideC. Sodium nitrideD. Sodium hydride.

On heating sodium metal in a current of ammonia the compound formed isA. Sodium nitrideB. Sodium hydrideC. Sodium amideD. Sodium azide.

Electrochemical process (electrolysis of fused salt) is employed to extractA. IronB. MgC. NaD. Both Na and Mg.

In the following reaction `NaOH+SrarrA+Na_(2)S+H_(2)O, A`A. `Na_(2)SO_(4)`B. `Na_(2)SO_(3)`C. `Na_(2)S`D. `Na_(2)S_(2)O_(3)`.

The stability of the following alkali metal chlorides follows the order:A. LiCl `gt` KCl `gt` NaCl `gt` CsClB. CsCl `gt` KCl `gt` NaCl `gt` LiClC. NaCl `gt` KCl `gt` LiCl `gt` CsClD. KCl `gt` CsCl `gt` NaCl `gt` LiCl.

In the Solvary process of manufacture of `Na_(2)CO_(3)`. the byproducts areA. `NH_(4)Cl, CaO`B. `CaO, Na_(2)CO_(3)`C. `CaCl_(2), CO_(2), NH_(3)`D. `Na_(2)CO_(3), CO_(2)`.

Assertion (A) `Rb_(2)CO_(3)+2Coverset(Delta)rarr2Rb +3CO` Reason (A) Rubidium cannot be produced by reduction with carbon.

Sodium metal cannot be stored underA. BenzeneB. Kerosene oilC. AlcoholD. Toluene

Sodium conducts electricity becauseA. It is a soft alkali metalB. It has only one electron in the outermost orbitC. It has mobile electronsD. It gives hydrogen with water.

The only oxidation state of alkali metals in their compounds isA. `+ 1`B. `+ 2`C. `- 1`D. zero.

`NaNO_(3)` on heating givesA. `O_(2)`B. `NO_(2)`C. `O_(2)+NO_(2)`D. none of these.