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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
When sodium is heated in flame it givesA. Golden yellow colourB. Crimson red colourC. Brick red colourD. Violet colour |
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Answer» Correct Answer - A |
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| 152. |
Which of the following represents the electronic configuration of the most electropositive element ?A. `[He]2s^(2)`B. `[Ne]3s^(2)`C. `[Asr]4s^(2)`D. `[Kr]5s^(2)` |
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Answer» Correct Answer - D A amongst the elements listed, `[Kr]5s^(2),` i.e. Sr has the biggest size and hence is the most electropositive element. |
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| 153. |
To remove exhaled `CO_(2)` by astronauts in spaceship, the chemical used isA. `LiOH`B. `NaOH`C. `Mg(OH)_(2)`D. `Ca(OH)_(2)` |
| Answer» Correct Answer - A | |
| 154. |
Which statement is false for an element, having 2,8,8,2 electronic configuration:-A. This element is of `II^(nd)` groupB. This element is of `IV^(th)` periodC. It forms `MO_(2)` type oxideD. It forms `M_(2)O` type oxide |
| Answer» Correct Answer - D | |
| 155. |
The alkali metals are soft due to-A. B.C.C. structureB. 68% packing efficiencyC. Weak metallic bondD. All the above |
| Answer» Correct Answer - D | |
| 156. |
Which of the following hydroxisde is used to prepare soft soaps ?A. LiB. KC. NaD. Ca |
| Answer» Correct Answer - B | |
| 157. |
Which of the following best decribes the alkali metals?A. They are diatomic and form ions of the general formula `X^(+)`B. They are monoatomic and from ions of the general formula `X^(-)`C. They are diatomic and from ions of the general formula `X^(2+)`D. They are monoatomic and from ions of the general formula `X^(+)` |
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Answer» Correct Answer - D |
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| 158. |
Mostly metals are hard, but metals of Ist A group are soft, because:-A. Their metallic bond is weakB. They have close packingC. They have face-centred cubic latticeD. Their b.p is low |
| Answer» Correct Answer - A | |
| 159. |
The element having atomic number 56 belongs toA. ActinidesB. Alkaline earth metalsC. Transition seriesD. Lanthanides |
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Answer» Correct Answer - B Barium `Ba_(56)` is a alkaline earth metal. |
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| 160. |
Which of the following more hard than the restA. NaB. CsC. KD. Li |
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Answer» Correct Answer - D |
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| 161. |
The element with atomic numbe 87 belongs toA. s-blockB. p-blockC. d-blockD. f-block |
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Answer» Correct Answer - A |
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| 162. |
Among the s-block elements, the matals that do not react with cold water is/areA. Li,Mg,BeB. Li,BeC. Mg,BeD. Be only |
| Answer» Correct Answer - C | |
| 163. |
Which is wrong regarding the density alkli metals?A. `Li lt Na`B. `Na lt K`C. `K lt Rb`D. `Rb lt Cs` |
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Answer» Correct Answer - B |
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| 164. |
Alkli matals are not characteised byA. Good conductors of heat and electricityB. High oxidation potentialsC. High melting pointsD. Solubility in ammonia |
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Answer» Correct Answer - C |
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| 165. |
Which one of the following alkali metals gives hydrated salts?A. LiB. NaC. KD. Cs |
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Answer» Correct Answer - A |
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| 166. |
The solubility of alkli metals salts in water is due to the fact that the cations get hydrated by water molecules. The degree of hydration depends upon the size of the cation. If the trend of relative ionic radii is `Cs^(+) gt Rb^(+) gt K^(+) gt Na^(+) gt Li^(+) `. What is the relative degree of hydration?A. `Cs_((aq))^(+) gt Rb+((aq))^(+) gt K_((aq))^(+) gt Na_((aq))^(+) gr Li_((aq))^(+)`B. `Li_((aq))^(+) gt Na_((aq))^(+) gtK_((aq))^(+) gt Rb _((aq))^(+) gt Cs_((aq))^(+)`C. `Na_((aq))^(+) gt K _((aq))^(+) gt Rb _((aq))^(+) gt Cs_((aq))^(+) gt Li_((aq))^(+)`D. `Cs_((aq))^(+) gt Na_((aq))^(+) gt Li_((aq))^(+) gt K_((aq))^(+) gt Rb_((aq))^(+)` |
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Answer» Correct Answer - B Smaller the size of cation, greater is its charge density and greater is its hydration. |
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| 167. |
The reaction of water sodium and potassium isA. ReversibleB. Irreversible and endothermicC. ExothermicD. Endothermic |
| Answer» Correct Answer - C | |
| 168. |
When CO is passed over solid NaOH heated to `200^(@)C` , it formsA. `Na_(2) CO_(3)`B. `H_(2)CO_(3)`C. `HCOONa`D. All |
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Answer» Correct Answer - C `underset("Solid")(NaOH)+ Co overset(200^(#)C)to underset("Sod. Formate")(HCOONa` |
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| 169. |
Alkali metals are generally extracted byA. Reduction methodsB. Doutble decomposition methodsC. Displacement methodsD. Electrolytic methods |
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Answer» Correct Answer - D Alkali metals are highly electropositive and thus higly reducing. There is no other stronger rducing agent than those of alkali methal. Therefore, raduction, double decompositin and displacement methods for their extraction are not suitable. Only electrolytic methods are useful for their exteir extraction. |
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| 170. |
Alkali metals can be extracted form their salts byA. Reduction with carbonB. Electrolysis of aqueous solution of their halidesC. Electrolysis of fused halidesD. Reduction with aluminium |
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Answer» Correct Answer - C |
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| 171. |
Identify the correct statement:A. Elemental sodium is esily oxidisedB. Eliemental sodium is soluble in ammoniaC. Elemental sodium can be prepared and isolated electrolysing an aqueous solution of sodium chlorideD. both 1 & 2 |
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Answer» Correct Answer - D |
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| 172. |
Excess of `Na^(+)` ions in our system causesA. High `BP`B. Low `BP`C. DiabetesD. Anaemia |
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Answer» Correct Answer - A Excess of `Na^(+)` ion causes high `BP` |
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| 173. |
An element having eolectronic configuration `[Rn]6_(s)^(1)` willA. From basic oxideB. Can be used in photoelectric cellC. Has high ionisation enthalpyD. both 1 & 2 |
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Answer» Correct Answer - D |
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| 174. |
Duralumin is an alloy ofA. `Mg+Cu+Al+Mn`B. `Mg+Cu`C. `Cu+Al`D. `Mg+Al` |
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Answer» Correct Answer - a `Cu-4%,Mg-0.05%` `Mn.0.5%. Al-95%` |
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| 175. |
Excess of `Na^(+)` ions in our system causesA. DiabetesB. AnaemiaC. Low blood pressureD. High bloos pressure |
| Answer» Correct Answer - D | |
| 176. |
"Electron" is an alloy ofA. Mg and ZnB. Fe and MgC. Ni and ZnD. Al and Zn |
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Answer» Correct Answer - A "Elektron" is an alloy of Mg `(95%)` and Zn `(5%)` used in the construction of aircraft. |
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| 177. |
An alloy of Na and K isA. Liquid at room temperatureB. Used in specially desinged thermodynamicsC. UnstableD. Solid at room temperature |
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Answer» Correct Answer - B |
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| 178. |
Which of the following is the best `CO_(2)` absorber as well as source of `O_(2)` in space capsule ?A. KOHB. `K_(2)O_(2)`C. `KO_(2)`D. LiOH |
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Answer» Correct Answer - C |
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| 179. |
Select wrong statemnts about alkali metalsA. All from superoxides `(MO_(2))`B. all from ionic hydrides `(MH_(2))`C. all from nitride `(M_(3)N)`D. all the above |
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Answer» Correct Answer - D |
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| 180. |
What happens when a mixture of sodium sulphate, lime stone and coke is heated in a furnace ?A. Black ash containing sodium carbonate and calcium sulphide is formed.B. Carbon dioxide gas is liberated.C. Sodium carbonate and calcium sulphate is formed.D. `(a)` and `(b)` both |
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Answer» Correct Answer - A `Na^(2)SO_(4)+CaCO_(3)+4C underset("furnace")overset(Delta)rarr ubrace(Na_(2)CO_(3)+CaS+CO)_("black ash")` |
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| 181. |
The order of basicity of hydroxides of alkali metals isA. `NaOH gt KOH gt RbOH`B. `NaOH gt RbOH gt KOH`C. `RbOH gt KOH gt NaOH`D. `RbOH gt NaOH gt KOH` |
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Answer» Correct Answer - C Basicity of hydroxides of alkali metals increases on descending the group. |
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| 182. |
Select the incorrect order for given properties :A. Thermal stability : `BaSO_(4)gtSrSO_(4)gtCaSO_(4)`B. Solubility : `BaSO_(4)gtSrSO_(4)gtCaSO_(4)`C. Thermal stability : `Li_(2)CO_(3)ltNa_(2)CO_(2)ltK_(2)CO_(3)`D. Solubility : `Li_(2)CO_(3)gtNa_(2)CO_(3)gtK_(2)CO_(3)` |
| Answer» Correct Answer - B::D | |
| 183. |
Hydrolysis of one mole of peroxodisulphuric acid producesA. two moles of sulphuric acidB. two moles of peroxomono sulphuric acidC. one mole opf sulphuric acid and one mole of peroxomono sulphuric acidD. one mole of sulphuric acid, one mple of peroxomono sulphuric acid and one mole of hydrogen peroxide |
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Answer» Correct Answer - C |
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| 184. |
The set representing the correct order of ionic radius isA. `Li^(+) gt Be^(2+) gt Na^(+) gt Mg^(2+)`B. `Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+)`C. `Li^(+) gt Na^(+) Mg^(2+) gt Be^(2+)`D. `Mg^(2+) gt Be^(2+) gt Li^(+) gt Na^(+)` |
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Answer» Correct Answer - B Is the correct order. In moving from left to right radii decreases while they increase downwards. `Li^(+)` and `Mg^(2+)` are diagonally related. The correct order is : `Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+)` |
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| 185. |
Consider (1) Sodium dissolves in ammonia to give a blue coloured solution (2) Sodium dies nto from amalgam with mercury (3) Sodium can be cut with a knife (4) Density of Na is more than that of Li Of the given statements, the correct areA. 1 and 2B. 3 and 4C. Only 2D. 1, 3 and 4 |
| Answer» Correct Answer - D | |
| 186. |
The charge/size ratio of a cation determines its polarising power. Which one of the following sequeces represents the increasing order of the polarising power of the cationic species, `K^(+),Ca^(2+),Mg^(2+),Be^(2+)`?A. `Ca^(2+) lt Mg^(2+) lt Be^(+) lt K^(+)`B. `Mg^(2+) lt Be^(2+) lt K^(+) lt Ca^(2+)`C. `Be^(2+) lt K^(+) lt Ca^(2+) lt Mg^(2+)`D. `K^(+) lt Ca^(2+) lt Mg^(2+) lt Be^(2+)` |
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Answer» Correct Answer - D High charge and small size of cation increases its polarising power. It is the correct order. |
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| 187. |
When `NaBH_(4)` is dissolved in waterA. `Na^(+) and BH_(4)^(-)` ions are formed which are stableB. It decomposes with the evolution of `H_(2)`C. `BH_(4)^(-)` is formed initially decompose to give `OH^(-)` ions, which prevent further decompositionD. `NaH and B_(2) H_(6)` are produced |
| Answer» Correct Answer - C | |
| 188. |
Which is maximum basic in the following ?A. `Na_(2)O`B. `BaO`C. `As_(2)O_(3)`D. `Al_(2)O_(3)` |
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Answer» Correct Answer - A `Na_(2)O` dissolves in water to form NaOH which is maximum basic |
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| 189. |
Which of the following compounds has the lowest anion to cation size ratio ?A. LiFB. NaClC. NaFD. KF |
| Answer» Correct Answer - D | |
| 190. |
Which of the following compounds has the lowest anion to cation size ratio ?A. LiFB. NaFC. CslD. CsF |
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Answer» Correct Answer - d For anion to cation ratio to be low, the anion must be small and cation must be large, i.e. `Cs^(+)F^(-)`. |
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| 191. |
`BeO + C Cl_(4) overset("Heat")(to)` |
| Answer» `2BeO + C CI_(2) overset("Heat")(to) 2BeCI_(2) + CO_(2)` | |
| 192. |
Ionic mobility of which of the following alkali metal ions is lowest when aqueous solution of their salts are put under an electric field ?A. `K`B. `Rb`C. `Li`D. `Na` |
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Answer» Correct Answer - C Ionic mobility `prop (1)/("size of hydrated ion")` Smallar size hydrated ion in aq. Solution `-Rb^(+)(aq)` Larger size hydrated ion in aq. Solution `-Li^(+)(aq)` Lowes ionic mobility in aq. Solution `rarr Li^(+)(aq)` due to high hydration. |
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| 193. |
Compared with the alkaline earth metals, the alkali metals exhibitA. smaller ionic radiiB. Higher boiling pointsC. Greater hardnessD. Lower ionisation enthalpies |
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Answer» Correct Answer - D Alkali metal have lower ionisation enthalpies `(DeltaiH^(1))` because of bigger size and less symmetrical configuration. |
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| 194. |
The correct order of solubility of the sulphates of alkaline earth metals in water isA. `Be gt Ca gt Mg gt Ba gt Sr`B. `Mg gt Be gt Ba gt Ca gt Sr`C. `Be gt Mg gt Ca gt Sr gt Ba`D. `Mg gt Ca gt Ba gt Be gt Sr` |
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Answer» Correct Answer - C Because of decrease in the magnitude of hydration enthalpy down the group. |
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| 195. |
Solubility of alkaline earth metal sulphates decreases down the group 2 becauseA. they become more ionicB. lattica energy of sulphates does not vary siginifacantlyC. hydration energy decreases rapidly from `Be^(2+)` to `Ba^(2+)`D. latica energy plays more predominant role than hydration energy |
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Answer» Correct Answer - c Duet to very large size of sulphate ions, the magnitude of lattice energy of alkaline earth metal sulphates remains almost constant. Thus, their solubility is only govermed by hydration energy which decreases from `Be^(2+)` to `Ba^(2+)` |
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| 196. |
Solubility of alkaline earth metal sulphates decreases down the group 2 becauseA. they become more ionicB. lattice energy of sulphates does not vary significantlyC. hydration energy decrease rapidly from `Be^(2+)` to `Ba^(2+)`D. lattice energy plays more predominant role than hydration energy. |
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Answer» Correct Answer - C Due to very large size of sulphate ions, the magnitude of lattice energy of alkaline earth metal sulphates remains almost constant. Thus, their solubility is governed by only hydration energy decreases fromo `Be^(2+)` to `Ba^(2+)`. |
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| 197. |
The correct order of solubility of alkali metal fluorides in water isA. `CsF lt NaF lt KF lt LiF`B. `LiF lt KF lt NaF lt CsF`C. `LiF lt NaF lt KF lt CsF`D. `CsF lt KF lt NaF lt LiF` |
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Answer» Correct Answer - C The correct order of solubility of alkali metal fluorides in water is `LiF lt NaF lt KF lt CsF` The solubility of alkali metal is inversely proportional to the lattice energy. More the lattice energy, lesser will be solubility . |
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| 198. |
The correct order of solubility isA. `CaCO_(3) lt KHCO_(3) lt NaHCO_(3)`B. `KHCO_(3) lt CaCO_(3) lt NaHCO_(3)`C. `NaHCO_(3) lt CaCO_(3) lt KHCO_(3)`D. `CaCO_(3) lt NaHCO_(3) lt KHCO_(3)` |
| Answer» Correct Answer - D | |
| 199. |
Sodium and potassium react with water much more vigorously than lithium because `:`A. sodium and potassium have high values of hydration energy as compared to that of lithium.B. sodium and potassium have higher melting point than that of lithium.C. sodium and potassium have lower melting point than that of lithium.D. sodium and potassium have lower hydration energy htan that of lithium. |
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Answer» Correct Answer - 3 When sodium and potassium react with water, the heat evolved causes them to meld, giving a larger area of contact with water, lithium on the other hand, does not melt under these condition and thus reacts more slowly. Melting point `(.^(@)C)` `{:(Li,Na,Na,),(180,98,64,):}` |
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| 200. |
Which of the following about solution lf alkali metals in lioquid ammonia is correct ?A. The solution have strong oxidizing properties.B. Both the dilute solution as well as concentrated solution are paramagnetic in nature.C. Charge transfer is the responsible for the colour of the solution.D. none of the above |
| Answer» Correct Answer - B | |