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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.
| 1201. |
Assertion . `Na_(2)SO_(4)` is soluble in water while `BaSO_(4)` is insoluble . Reason. Lattice energy of barium sulphate exceeds its hydration energy .A. If both assertion and reason are true, and reason is the true explanation of the assertion.B. If both assertion and reason are true, but reason is not the true explanation of the assertion.C. If assertion is true, but reason is falseD. If both assertion and reason are false. |
| Answer» Correct Answer - a | |
| 1202. |
How will you distinguish between (i) magnesium and calcium (ii) `Na_(2)SO_(4)` and `BaSO_(4)` |
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Answer» (i) Calcium when heated imparts brick red colour to the flame but magnesium does not . (ii) `Na_(2)SO_(4)` is soluble in water but `BaSO_(4)` is insoluble . |
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| 1203. |
Why `BaSO_(4)` is insoluble whereas `BeSO_(4)` is soluble in water ? |
| Answer» The lattice enthalpy of `BaSO_(4)` is much than its hydration enthalpy and hence it is insoluble in water . But on, the other hand , hydration enthalpy of `BeSO_(4)` is much higher than its lattice enthalpy because of small size of `Be^(2+)` ions . Therefore , it is highly soluble in water . | |
| 1204. |
Alkali and alkaline earth metals along with hydrogen and helium constitute s-block elements . They have low ionization enthalpies and hence exhibit characteristic flame colouration . They have highly negative electrode potentials and hence are strong reducing agents . Their solutions in liquid ammonia are conducting and also act as strong reducing agents than hydrogen , they are usually prepared by electrolysis of their fused chlorides . Their oxides are basic and the basic strength increases down the group . The solubility of carbonates and sulphates of alkali and alkaline earth metals show opposite trends . The carbonates of alkaline earth metals and lithium carbonate decompose on heating while the carbonates of other alkali metals do not decompose on heating . The bicarbonates of both alkali and alkaline earth metals on heating give carbonates . The compound insoluble in acetic acid isA. calcium oxideB. calcium carbonateC. calcium oxalateD. calcium hydroxide . |
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Answer» Correct Answer - C `CaO , CaCO_(3)` and `Ca(OH)_(2)` are all bases and hence must dissolve in acetic acid to form calcium acetate . Only calcium oxalate does not dissolve in `CH_(3)COOH` . |
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| 1205. |
The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:A. `Li^(+)ltK^(+)ltNa^(+)ltRb^(+)`B. `Rb^(+)ltK^(+)ltNa^(+)ltLi^(+)`C. `K^(+)ltNa^(+)ltRb^(+)ltLi^(+)`D. `Na^(+)ltLi^(+)ltK^(+)ltRb^(+)` |
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Answer» Correct Answer - b Ease of adsorption of the hydrated alkali metal ions on an ion exhchange resins decreases as the size of alkali metal ions increases. Since, the order of size of alkali metal ions is `Li^(+)ltNa^(+)ltK^(+)ltRb^(+)` Thus, the ease of adsorption follows the order `Rb^(+)ltK^(+)ltNa^(+)ltLi^(+)` |
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| 1206. |
Name one reagent or one operation to distinguish between (i) `BeSO_(4)` and `BaSO_(4)` (ii) `Be(OH)_(2)` and `Ba(OH)_(2)` (iii) `Na_(2)CO_(3)` and `NaHCO_(3)` |
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Answer» (i) Water : `BeSO_(4)` is soluble in `H_(2)O` while `BaSO_(4)` is not (ii) Alkali : `Be(OH)_(2)` dissolves in alkali but `Ba(OH)_(2)` does not (iii) Heat : `NaHCO_(3)` on heating gives `CO_(2)` which turns lime water milky . In constrast , `Na_(2)CO_(3)` does not decompose on heating to form `CO_(2)`. |
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| 1207. |
Why are `BeSO_(4)` and `MgSO_(4)` readily soluble in water while `CaSO_(4) , SrSO_(4)` and `BaSO_(4)` are insoluble ? |
| Answer» Because of big size of `SO_(4)^(2-)` ion as compared to `Be^(2+)` and `Mg^(2+)` ions , the lattice enthalpies of `BeSO_(4)` and `MgSO_(4)` are almost the same . But because of small size of `Be^(2+)` and `Mg^(2+)` ions their hydration enthalpies are much higher than their corresponding lattice enthalpies . As a result , `BeSO_(4)` and `MgSO_(4)` are highly soluble in water . | |
| 1208. |
Why are `BeSO_(4)` and `MgSO_(4)` readily soluble in water while `CaSO_(4),SrSO_(4)` and `BaSO_(4)` are insoluble? |
| Answer» In general,the solubility of the sulphates of alkaline earth metals in water decreases down the group. Thus, `BeSO_(4)` is maximum soluble in water while `BaSO_(4)` is almost insoluble. | |
| 1209. |
The ease of absorption of hydrated alkali metal ions on an 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^(+)` |
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Answer» Correct Answer - A Larger the size of the hydrated cation , smaller is the ease of absorption . Thus , case of absorption increases in the order : `Li^(+) lt Na^(+) lt K^(+) lt Rb^(+) ` i.e., option (a) is correct . |
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| 1210. |
Statement- 1. Among the alkali metals , caesium salts exhibit the maximum electrical conductance in aqueous solutions . Statement- 2 . The radius of hydrated caesium ion is the highest among alkali metals .A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for statement-1.C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True. |
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Answer» Correct Answer - c Correct explanation-2 . The radius of hydrated caesium ion is the smallest . |
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| 1211. |
Discuss the trend of the following : (i) Thermal stability of carbonates of Group 2 elements . (ii) The solubility and the nature of oxides of Group 2 elements . |
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Answer» (ii) All alkaline earth metals react with `O_(2)` to form their respective oxides (MO) , their reactivity , however , increases down the group with increase in atomic size . Solubility in water . BeO being covalent is insoluble in water , MgO is only sparingly soluble in wate but all other oxides , i.e. , CaO , SrO and BaO dissolve in water with evolution of heat forming their corresponding hydroxides . `CaO + H_(2)O to Ca(OH)_(2) + ` heat The solubility of these oxides/hydration increase down the group because both the their lattice enthalpies and hydration enthalpies decrease down the group but their lattice enthalpies decrease more rapidly than their hydration enthalpies . Nature of oxides . Due to small size and somewhat high ionization enthalpy of Be, BeO is amphoteric and dissolves in both acids and alkalies . `BeO + 2HCl to BeCl_(2) + H_(2)O , BeO + 2 NaOH to underset("Sodium berrylate")(Na_(2)BeO_(2)) + H_(2)O` All other oxides are basic in nature and their basic character increases down the group . |
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| 1212. |
Solubility of the alkaline metal sulphates in water decreases in the sequence .A. `Sr gt Ca gt Mg gt Ba`B. `Ba gt Mg gt Sr gt Ca`C. `Mg gt Ca gt Sr gt Ba`D. `Ca gt Sr gt Ba gt Mg` |
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Answer» Correct Answer - C The solubility of alkaline earth metal sulphates decreases down the group due to a corresponding decrease in hydration enthalpy . |
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| 1213. |
Which of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy ?A. `BaSO_(4)`B. `SrSO_(4)`C. `CaSO_(4)`D. `BeSO_(4)` |
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Answer» Correct Answer - D Among alkaline earth metal sulphates , lattice enthalpy remains almost constant but hydration enthalpy decreases down the group . Thus , `BeSO_(4)` has higher hydration enthalpy as compared to lattice enthalpy . |
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| 1214. |
The sulphates of which of the following metals dissolve in water . `SrSO_(4) , K_(2)SO_(4) , BeSO_(4) , Li_(2)SO_(4) , MgSO_(4) , BaSO_(4) , Na_(2)SO_(4) , CaSO_(4) , Rb_(2)SO_(4)`. |
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Answer» Correct Answer - 6 Six , `K_(2)SO_(4) . BeSO_(4) , Li_(2)SO_(4) , MgSO_(4) , Na_(2)SO_(4) , Rb_(2) SO_(4)`. |
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| 1215. |
Which one of the following alkali metals gives hydrated salts ?A. LiB. NaC. KD. Cs |
| Answer» Among alkali metal ions , `Li^(+)` is the smallest . Therefore , it has the highest charge density and hence attracts the water molecules more strongly than any other alkali metal cation . Thus , option (a) is correct . | |
| 1216. |
Which of the following is least thermally stableA. `MgCO_(3)`B. `CaCO_(3)`C. `SrCO_(3)`D. `BeCO_(3)` |
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Answer» Correct Answer - D Since `Be(OH)_(2)` is least basic , therefore , its carbonate is least stable , i.e., option (d) is correct . |
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| 1217. |
Assertion . `Li_(2)CO_(3)` and `Na_(2)CO_(3)` are thermally stable. Reason . Both the carbonates are salts of large cations and large anions .A. If both assertion and reason are true, and reason is the true explanation of the assertion.B. If both assertion and reason are true, but reason is not the true explanation of the assertion.C. If assertion is true, but reason is falseD. If both assertion and reason are false. |
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Answer» Correct Answer - d Correct assertion . `Li_(2)CO_(3)` is unstable and decompose on heating to form `Li_(2)O` and `CO_(2)` but `Na_(2)CO_(3)` is thermally stable . Correct reason . `Li_(2)CO_(3)` is thermally unstable because it is salt of a small cation and big anion . In contrast , `Na_(2)CO_(3)` is thermally stable because a bigger cation stabilizes a bigger anion . |
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| 1218. |
Why does the solubility of alkaline earth metal carbonates and sulphates in water decrease down the group ? |
| Answer» The size of `CO_(3)^(2-)` and `SO_(4)^(-)` ions are much bigger than those of the cations . Therefore , the lattice enthalpies of carbonates and sulphates remain almost the same as we move down the group . Since the hydration enthalpies decrease as the size of the cation increases down the group , the solubility of carbonates and sulphates of alkaline earth metals decreases down the group . | |
| 1219. |
Among the following , the least thermally stable isA. `K_(2)CO_(3)`B. `Na_(2)CO_(3)`C. `BaCO_(3)`D. `Li_(2)CO_(3)` |
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Answer» Correct Answer - D Among `Li^(+) , Na^(+) , K^(+)` and `Ba^(2+) , Li^(+)` has the smallest size and hence the highest polarising power . As a result , `Li_(2)CO_(3)` has the least ionic character and hence has the least stability . |
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| 1220. |
According to Fajan rules , the percentage of covalent character in an ionic compound increases . If the cation is highly charged or the cation is small and the anion is large or the cation has pseudo inert gas configuration . As a result of increased covalent character , the melting point decreases and solubility in less polar solvent increases . The correct order of increasing ionic character isA. `BeCl_(2) lt MgCl_(2) lt CaCl_(2) lt BaCl_(2)`B. `BeCl_(2) lt MgCl_(2) lt BaCl_(2) lt CaCl_(2)`C. `BeCl_(2) lt BaCl_(2) lt MgCl_(2) lt CaCl_(2)`D. `BaCl_(2) lt CaCl_(2) lt MgCl_(2) lt BeCl_(2)` |
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Answer» Correct Answer - A As the size of the cation increases , electronegativity decreases but the electronegativity difference increases and hence ionic character increases accordingly , i.e., option (a) is correct . |
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| 1221. |
Which one of the following alkaline earth metal carbonates is thermally the most stable ?A. `MgCO_(3)`B. `CaCO_(3)`C. `SrCO_(3)`D. `BaCO_(3)` |
| Answer» As the electropositive character of the metal increases or the basicity of their hydroxides increases down the group, their thermal stability increases . Thus , `BaCO_(3)` is the most stable and hence option (d) is correct . | |
| 1222. |
The alkaline earth metal which has the least density is :A. MgB. BeC. SrD. Ca |
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Answer» Correct Answer - D Ca has the least density . |
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| 1223. |
The set representing the correct order of ionic radii isA. `Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+)`B. `Li^(+) gt Na^(+) gt Mg^(2+) gt Be^(2+)`C. `Mg^(2+) gt Be^(2+) gt Li^(+)gt Na^(+)`D. `Li^(+) gt Be^(2+) gt Na^(+) gt Mg^(2+)` |
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Answer» Correct Answer - A The ionic radii of alkali metal ions are larger than those of the corresponding alkaline earth metal ions . Also ionic radii increase down the group . Therefore , the ionic size radii decrease in the order : `Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+) ` i.e., option (a) is correct . |
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| 1224. |
Why are lithium salts commonly hydrated while those of other alkali metal ions ar usually anhydrous? |
| Answer» In the lithium salts, the lithium ion `(Li^(+))` due to very small size gests readily hydrated on coming in contact with moisture (or water). Therefore, lithium salts are commonly hydrated. But the other alkali metal ions are comparatively big in size. They hav therefore, lesser tendency to get hydrated. These salts are usually anhydrous. | |
| 1225. |
Complete and balance the following equations. (i) `Mg(HCO_(3))_(2) + Ca(OH)_(2) to MgCO_(3) + … + H_(2)O` (ii) `MgO + CaC_(2) to Mg + …. 2C` (iii) `CaO + c overset("Heat")(to) … + CO` |
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Answer» (i) `Mg(HCO_(3))_(2) + Ca(OH_(2) to MgCO_(3) + CaCO_(3) + 2H_(2) O` (ii) `MgO + CaC_(2) overset("Heat")(to) Mg + CaO + 2C` (iii) `CaO + 3C overset("Heat")(to) CaC_(2) + CO` |
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| 1226. |
Highly pure dilute solution of sodium in ammonia :A. shows blue colouration due to solvated electronsB. shows electrical conductivity due to both solvated electrons as well as solvated sodium ionsC. shows red colouration due to solvated electrons but a bad conductor of electricityD. produces hydrogen gas or carbonate |
| Answer» Correct Answer - A::B | |
| 1227. |
A highly pure dilute solution of sodium in liquid ammonia:A. shows blue colourB. do not exhibit electrical conductivityC. produces sodium amideD. produces hydrogen gas |
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Answer» Correct Answer - A Due to ammonia solvated electrons. |
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| 1228. |
`CsBr_(3)` containsA. `Cs-Br` covalent bondsB. `Cs^(3+)" and "Br^(-)` ionsC. `Cs^(+)" and "Br_(3)^(-)` ionsD. `Cs^(3+)" and "Br_(3)^(3-)` ions |
| Answer» Correct Answer - C | |
| 1229. |
A fire of lithium , sodium and potassium can be extinguished byA. `H_(2)O`B. NitrogenC. `CO_(2)`D. Asbestos blanket |
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Answer» Correct Answer - C Carbon dioxide does not help in burning, also it forms carbonate with alkali metals. |
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| 1230. |
Which statement is false in case of alkali metals ?A. Lithium is the strongest reducing agentB. Sodium is amphoteric in natureC. `Li^(+)` ion is exceptionally smallD. All alkali metals give blue colour in liquid ammonia |
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Answer» Correct Answer - B Alkali metals are strong bases and sodium hydroxide cannot be amphoteric in nature |
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| 1231. |
A sodium fire in the laboratory is extinguished byA. `CCI_(4)`B. sandC. waterD. kerosene |
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Answer» Correct Answer - A Only `C CI_(4)` is highly non-inflammable. Sand contains some moisture while kerosene is highly flammable. |
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| 1232. |
Which of the following on thermal decomposition yields a basic as well as an acidic oxide?A. `KClO_(3)`B. `CaCO_(3)`C. `NH_(4)NO_(3)`D. `NaNO_(3)` |
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Answer» Correct Answer - B `CaCO_(3) overset(Delta)rarr underset("basic oxide")(CaO)+underset("Acidic oxide")(CO_(2))` |
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| 1233. |
Which of the following on thermal decomposition yields a basic as well as an acidic oxide?A. `NH_(4)NO_(3)`B. `NaNO_(3)`C. `KCIO_(3)`D. `CaCO_(3)` |
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Answer» Correct Answer - D `CaCO_(3) rarr underset("basic")(CaO)+ underset("acidic")(CO_(2))` |
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| 1234. |
Which reaction is not feasible?A. `HCequivCH+LirarrLi^(+)overset(-)Cequivoverset(-)CLi^(+)+H_(2)`B. `4NaNO_(3)overset(Delta)rarr2Na_(2)O_(2)+4NO_(2)+O_(2)`C. `LiCl+2H_(2)OrarrLiCl.2H_(2)O`D. `MgCl_(2)+6H_(2)OrarrMgCl_(2).6H_(2)O` |
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Answer» Correct Answer - A::B (a) Li does not form ethynide. (b) `2NaNO_(3)overset(Delta)rarr2NaNO_(2)+O_(2)` |
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| 1235. |
`F_(2)+2% NaOH to W+ X +Y` `F_(2)+ conc NaOH to Z+X+Y` Which of the following is wrong statement?A. W is `OF_(2)`B. W is `O_(2)F_(2)`C. Z is `O_(2)`D. X and Y are NaF and `H_(2)O` |
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Answer» Correct Answer - B |
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| 1236. |
Which of the following reaction is not feasible.A. `Zn+NaOH+NaOHrarr Na_(2)ZnO_(2)+N_(2)+H_(2)O`B. `Al+NaOH+H_(2)O to NaAlO_(2)+H_(2)`C. `Br_(2)+Na_(2)CO_(3)toCaBr+NaBrO_(3)+CO_(2)`D. `Sn+NaOH+H_(2)OtoNa_(2)SnO_(3)+H_(2)` |
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Answer» Correct Answer - A |
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| 1237. |
Which of the following is true ?A. Sodium when heated in excess of exygen it hives oxideB. Oxidation state of oxygen in `KO_(2)` is -1C. Sodium amalgam is better reducing agent then hydrogenD. Sodium nitrate on heating gives introgen dioxide |
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Answer» Correct Answer - C |
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| 1238. |
`aq.NaOH+P_(4)(white)rarrPH_(3)+X,` compound X is :A. `NaH_(2)PO_(2)`B. `NaH_(2)PO_(4)`C. `Na_(2)CO_(3)`D. `NaHCO_(3)` |
| Answer» Correct Answer - A | |
| 1239. |
What would you observe if excess of dilute NaOH solution is added and shaken with an aq solution of aluminium chloride?A. Permance white precipitate is formed immediately.B. Bonchange at first but a white precipitate is formed on standing.C. A white precipitate is formed which later dissolves.D. A green precipitate which turns red on standing in air. |
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Answer» Correct Answer - C |
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| 1240. |
If NaOH is added to an aqueous solution of `Zn^(2+)` ions a white precipitate apperars and on adding excess of NaOH, the precipitate dissolves. In this solution Zinc exists in_____A. Cationic partB. Anionic partC. Both in cationic and anionic partD. There is no zinc left in the solution |
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Answer» Correct Answer - B `NaOH+Zn^(+2)rarrunderset(Na_(2)ZnO_(2)"soluble")underset(" "darr"excessive")underset(" ""white ppt")(Zn(OH)_(2))` |
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| 1241. |
If NaOH is added to an aqueous solution of `Zn^(2+)` ions a white precipitate apperars and on adding excess of NaOH, the precipitate dissolves. In this solution Zinc exists in_____A. Cationic partB. Anionic partC. both in cationic and anionic parts 0D. There is no zine left in the solution |
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Answer» Correct Answer - B |
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| 1242. |
When sulphur is heated with NaOH (aq) the compounds formed are:A. `Na_(2)S+H_(2)O`B. `Na_(2)SO_(3)+H_(2)O`C. `Na_(2)S_(2)+Na_(2)S_(2)O_(3)+H_(2)O`D. `Na_(2)S_(2)O_(3)+H_(2)O` |
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Answer» Correct Answer - C |
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| 1243. |
Baking powder contains:A. `NaHCO_(3), Ca(H_(2)PO_(2))_(2)` and starchB. `NaHCO_(3), Ca(H_(2)PO_(2))_(2)`C. `NaHCO_(3)`, starchD. `NaHCO_(3)` |
| Answer» Correct Answer - A | |
| 1244. |
When a standard solution of NaOH is left in air for a few hours:A. a precipitate will fromB. strngth of solution will decreaseC. the strength of solution will increaseD. the concentration of `Na^(+)` ion in solution will remain same |
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Answer» Correct Answer - B |
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| 1245. |
If NaOH is added to an aqueous solution of `Zn^(2+)` ions a white precipitate apperars and on adding excess of NaOH, the precipitate dissolves. In this solution Zinc exists in_____A. Cationic partB. Anionic partC. Both in cationic and anionic partsD. There is no zinc left in the solution |
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Answer» Correct Answer - B |
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| 1246. |
Baking powder contains:A. `NaHCO_(3), Ca(H_(2)PO_(4))_(2)` and starchB. `NaHCO_(3), Ca(H_(2)PO_(2))_(2)`C. `NaHCO_(3),` StarchD. `NaHCO_(3)` |
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Answer» Correct Answer - A Baking powder contains `NaHCO_(3) , Ca(H_(2)PO_(4))` and starch. |
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| 1247. |
Baking powder used to make cake is a mixture of starch, `NaHCO_(3)` and `Ca(H_(2)PO_(4))_(2^.)` The function of `Ca(H_(2)PO_(4))_(2)` isA. to slow down the relese of `CO_(2)` gasB. it has acidic hydrogen and gives `CO_(2)` when moistened with `NaHCO_(3)`C. to act as a filterD. None of these |
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Answer» Correct Answer - B |
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| 1248. |
On being placed in water, sodium peroxide not only produces an alkaline solution but also bubble. If we assume that the peroxide ion picks up two protons from water to profice a compound that can be seen as the dibasic conjugate acid of peroxide ion and then this compound undergoes a rodox disproportion `Na_(2)O(s)+H_(2)O(l)to(A)+(B)," "(A) "adn"(B)"are"`A. `H_(2)O_(2)` and `NaOH`B. `H_(2)O` and `O_(2)`C. `NaOH` and `O_(2)`D. `N a_(2)O` and `NaOH` |
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Answer» Correct Answer - C |
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| 1249. |
Baking powder is a mixture of (i) `NaHCO_(3)` , (ii) starch (iii) `Ca(H_(2)PO_(4))_(2) , (iv) NaAI(SO_(4))_(2)`A. `Ca(H_(2)PO_(4))_(2)` is acidic and when moistened it reacts with `NaHCO_(3)` evolving `CO_(2)` gas.B. NaAl `(SO_(4))_(2)` slows down the decomposition reaction of `NaHCO_(3)` so that `CO_(2)` is evolved more sloely.C. NaAl `(SO_(4))_(2)` is acidic and when moistened it reacts with `NaHCO_(3)` evolving `CO_(2)`D. Both (a) and (b) |
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Answer» Correct Answer - D |
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| 1250. |
Bakng powder used to make cake is a mixture of starch, `NaHCO_(3)` and `Ca(H_(2)PO_(4))_(2^.)` The function of `Ca(H_(2)PO_(4))_(2)` isA. to slow down the release of `CO_(2)` gasB. being acidic in nature and gives `CO_(2)` when moistened with `NaHCO_(3)`C. to act as a fillerD. None of these |
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Answer» Correct Answer - B |
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