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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.
| 251. |
The correct sequence of increasing covalent character is represented byA. `BeCl_(2) lt naCl lt LiCl`B. `BaCl lt LiCl lt BeCl_(2)`C. `BeCl_(2) lt LiCl lt NaCl`D. `LiCl lt NaCl lt BeCl _(2)` |
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Answer» Correct Answer - B Covalent character increases in thr order `NaCl lt LiCl lt BeCl_(2)` as the size of the metal ion decreases. |
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| 252. |
Why the elements of second row (first short period) show a number of differences in properties from other members of their respective families ? |
| Answer» The difference in the properties of the first member of a group from those of the other members is due to (i) smaller size of the atom (ii) presence of one inner shell of only two electrons and (iii) absence of a orbitals . | |
| 253. |
Which of the following statement is incorrect for alkalli metal compounds ?A. superoxides are paramagnetic in natureB. basic strength of hydroxides decreases down the group.C. the conductivity of chlorides in their aqueous solutions decreases down the group.D. the basic nature of carbonates in aqueous solutions is due to anionic hydrolysis . |
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Answer» Correct Answer - B |
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| 254. |
Setting of plaster of paris isA. Oxisation with atomospheric oxygenB. endothermic reactionC. dehydrationD. hydration |
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Answer» Correct Answer - D |
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| 255. |
Which of the followings salts on heating gives a mixture of two gases ?A. `Ba(NO_(3))_(2)`B. `NaNO_(3)`C. `KNO_(3)`D. `RbNO_(3)` |
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Answer» Correct Answer - A `Ba(NO_(3))_(2)overset(Delta)rarr BaO+2NO_(2)+(1)/(2)O_(2),` Alkali metal nitrates give only `O_(2)` gas. Alkali metal nitrates give only `O_(2)` on heating below `500^(@)C` according to following reaction. `MNO_(3) rarr MNO_(2)+O_(2)` |
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| 256. |
Identify the correct statement-A. Gypsum contains a lower percentage of Ca than plaster of parisB. Gypsum is obtained by heating plaster of parisC. Plaster of paris can be obtained by hydration of gypsumD. Plaster of paris is obtained by partial oxidation of gypsum |
| Answer» Correct Answer - A | |
| 257. |
Setting of plaster of Paris involvesA. the oxidation with atmospheric oxygen.B. the removal of water to form anhydrous calcium sulphate.C. the hydration to form the othorhombic form of gypsum.D. the reaction with atmospheric carbon dioxide gas |
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Answer» Correct Answer - C `2CaSO_(4).H_(2)Ounderset(+H_(2)O)overset("setting")rarrCaSO_(4).2H_(2)O` (orthohombic gypsum). |
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| 258. |
Plaster of Paris hardens byA. giving off `CO_(2)`B. utilizing waterC. changing into `CaCO_(3)`D. giving out water |
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Answer» Correct Answer - B `2CaSO_(4).H_(2)O overset("Setting")underset(H_(2)O)rarrCaSO_(4).2H_(2)Ooverset("Harding")rarrCaSO_(4).2H_(2)O` |
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| 259. |
(a) Which compound of sodium is used for softening hard water? (b) What is the effect of heat on the compounds ? (Write equations for the reactions): (c ) Draw the structure of : (i) `BeCI_(2)` (in vapour state) (ii) `BeCI_(2)` (in solid state) |
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Answer» (a) Sodium hydrogen carbonate `(NaHCO_(3))` is used for softening hard water. (b) `underset(("Glysum"))(CaCO_(2)) overset("Heat")(to) CaO + CO_(2)` (ii) `underset(("Glysum"))(CaSO_(4).2H_(2)O) overset("Heat")(to) underset(("Plaster of pairs"))(CaSO_(4).1//22H_(2)O) + 3//2 H_(2)O` |
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| 260. |
which has the maximum m.p ?A. NaClB. NaFC. NaBrD. Nal |
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Answer» Correct Answer - B NaF is maximum ionic and has highest melting point |
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| 261. |
The stability of the following alkali metal chlorides follows the order:A. `LiCI gt KCI gt NaCI gt CsCI`B. `CsCI gt KCI gt NaCI gt LiCI`C. `NaCl gt KCI gt LiCI gt CsCI`D. `KCI gt CsCI gt NaCI gt LiCI` |
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Answer» Correct Answer - D The stability of compound is linked with enthalpy of formation. Smaller the value, (greater the negative value) more will be the stability. Based on the values, LiCI is least stable while KCI is maximum stable `Delta_(f) H` for LiCI = - 408.8 kJ `mol^(-1)` `Delta_(f) H` for NaCI = - 412.5 kJ `mol^(-1)` `Delta_(f) H` for CsCI =- 433.0 kJ `mol^(-1)` `Delta_(f) H` for KCI = - 436.0 kJ `mol^(-1)` |
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| 262. |
The stability of the following alkali metal chlorides follows the order:A. `LiCL gt KCl gt NaCl gr CsCl`B. `CsCl gt KCl gt NaCl gt LiCl`C. `NaCl gt KCl gt LiCl gt CsCl`D. `KCl gt CsCl gt NaCl gt LiCl` |
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Answer» Correct Answer - D Stability of a compound depends upon its enthaolpy of formation `DeltaH_(f).` The more negative value of `DeltaH_(f)` show more stable of a compound. Thus KCl is more stable and LiCl is least stable. `DeltaH_(f) ` for `LiCl=-408.8 kJ mol ^(-1)` `Delta H_(f) ` for `NaCl=-412.5kJ mol ^(-1)` `Delta H_(f)` for `CsCl =-433 kJ mol ^(-1)` `Delta H_(f)` for `KCl =-436 kJ mol ^(-1)` |
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| 263. |
Which of the following has the highest melting point ?A. NaClB. NaFC. NaBrD. NaI |
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Answer» Correct Answer - B NaF due to its largest lattice energy has the highest melting point. |
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| 264. |
Which of the following halides has the highest melting point-A. `NaCI`B. `KCI`C. `NaBr`D. `NaF` |
| Answer» Correct Answer - D | |
| 265. |
Alkali metals show-A. Only `+1` oxidation stateB. Only `-1` oxidation stateC. `+1` and `+2` oxidation statesD. `-1` and `-2` oxidation states |
| Answer» Correct Answer - A | |
| 266. |
The density of-A. `Na gt K`B. `Na = K`C. `K gt Na`D. `Li gt K` |
| Answer» Correct Answer - A | |
| 267. |
Which of the following metal will give apple green colout on Busen flame-A. `Ba`B. `Sr`C. `Ca`D. K |
| Answer» Correct Answer - A | |
| 268. |
Which of the following properties among halogens decreases from fluorine to iodine ?A. densityB. Solubility of sulphateC. Solubolity of oxalateD. basic strength of `M(OH)_(2)` |
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Answer» Correct Answer - B |
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| 269. |
Which causes nerve signals in animals?A. Electrcal potential gradient due to transfer of `K^(+)` ionsB. Electrical potential gradient due to transfer of `Ca^(2+)` ions in `(Na^(+)-K^(+))` pumpsC. Electrical potential gradient due to transfer of `Ca^(2+)`D. No never signal exists in animals |
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Answer» Correct Answer - A |
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| 270. |
The compound called microscomic salt is:A. `Na_(2)HPO_(4^.)2H_(2)O`B. `Na_(2)(NH_(4))HPO_(4^.)4H_(2)O`C. `Na_(2)NH_(4)PO_(4^.)2H_(2)O`D. `(NH_(4))_(2)HPO_(4^.)2H_(2)O` |
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Answer» Correct Answer - B |
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| 271. |
Alkaline earth metal nitrates on heating decompose to give `:`A. `M(NO_(2))_(2)` and `O_(2)` onlyB. `MO,N_(2)` and `O_(2)`C. `MO,NO_(2)` and `O_(2)`D. `MO` and `NO_(2)` only |
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Answer» Correct Answer - C `2M(NO_(3))_(2)overset(Delta)rarr2MO+NO_(2)+O_(2)(M=Be,Mg,Ca,Sr,Ba)` |
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| 272. |
Which of the following statements reagarding alkali metals is not correct?A. Alkali metals are reactive.B. They belong s-block of periodic tabelC. They hydroxides are alkaline in natere.D. They from carbonates which decompse on heating. |
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Answer» Correct Answer - D |
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| 273. |
In which one of the followig sets are there three members of the alkaline earth family of metals ?A. Aluminium, sodium, potassiumB. Lithium, sodium, potassiumC. Magnesium, barium, calciumD. Rubidium, caesium, francium |
| Answer» Correct Answer - C | |
| 274. |
Select from each of the following sets those elements which belong to the same group of sub-group of the periodic table ?A. At. Nos. `12,4,88`B. At. Nos. `9,16,35,3`C. At nos. `11,19,27,5`D. At.nos, `24,47,42,55` |
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Answer» Correct Answer - A Atomic numbers `:12 (Mg) , 38 (Sr) , 4 (Be) , 88 (Ra)` represent alkaline earth metals. |
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| 275. |
Which is not anm ore of Ca ?A. lime stone B. FluorsparC. DolomiteD. Epsom salt |
| Answer» Epsom salt is `MgSO_(4). 7H_(2)O,` an ore of magnesium. | |
| 276. |
The ore of potassium isA. bauxiteB. dolomiteC. carnaliteD. cryolite |
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Answer» Correct Answer - c `KCl.MgCl_(2).6H_(2)O` (carnalite) is an ore of potassium. |
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| 277. |
Which is not anm ore of Ca ?A. lime stoneB. FluorsparC. DolomiteD. Epsom salt |
| Answer» Epsom salt is `MgSO_(4). 7H_(2)O,` an ore of magnesium. | |
| 278. |
Which of the following statement about the sulphate of alkali metal is correct ?A. Ecept `Li_(2)SO_(4)` all sulphate of other alkali metals are soluble in waterB. All sulphates of alkali metals except lithium sulphate forms alumC. The sulphates of alkali metals except lithium sulphate do not decompose at high temperatureD. All of the above |
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Answer» Correct Answer - D Li does not form alum because of small size of `Li^(+)`. |
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| 279. |
Which of the following statement about the sulphate of alkali metal is correct ?A. Except `Li_(2)SO_(4),` all sulphated of other metals are soluble in water.B. All sulpher of alkali metal except lithium sulphate froms alums.C. The sulphated of alkali metals connot be hydrolysed.D. All of these |
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Answer» Correct Answer - D |
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| 280. |
The sulphate of which metal does not form alum:-A. `Li`B. `Na`C. KD. `Cs` |
| Answer» Correct Answer - A | |
| 281. |
In aqueous solution, the largest ion is :A. `Na(aq)`B. `Cs(aq.)`C. `Rb(aq.)`D. `Li(aq.)` |
| Answer» Correct Answer - D | |
| 282. |
The radius of which hydrated ion is largestA. `RB^(+)`B. `K^(+)`C. `Na^(+)`D. `Li^(+)` |
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Answer» Correct Answer - D |
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| 283. |
The alkaline reath metal ion that has least electrical conducitivty in aqueous solution isA. `Ba^(2+)`B. `Ca^(2+)`C. `Be^(2+)`D. `Cs^(+)` |
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Answer» Correct Answer - 3 |
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| 284. |
Assertion : Caesium is used in photoelectric cells. Reason : Caesium is most electropositive element.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - a Because of the low ionization enthalpy of caesium, when irradiated with light, the light energy absorbed in sufficient to make an atom lose electron. This property makes caesium useful as electrodes in photoelectric cells. |
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| 285. |
Lithium ion batteries are now commonly used in rechargeable consumer electronic devices. The main reason lithium is used in these devices is because :A. lithium has a lower electronegativity than nickel in common nickel-cadmium batteriesB. lithium batteries are not as toxic as common alkaline batteriesC. lithium batteries have a reduced risk of leakage of chemicalsD. lithium batteries achieve a greater amount of energy stored per unit mass than other common batteries |
| Answer» Correct Answer - D | |
| 286. |
Alkali metals are soft ans have relatively low m.pt. and low density. This is becauseA. Interatomic bonds are weakB. Interatomic bond are strongC. Of their ionisation potentialD. Of their position in the periodic table |
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Answer» Correct Answer - A |
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| 287. |
Sodium gets dissolved in liquid ammonia because of ____________ .A. The adsorption of hydrogen by palladium is commonly known as…….B.C.D. |
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Answer» Correct Answer - solvated electrons |
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| 288. |
The lightest metal known isA. BerylliumB. LithiumC. SodiumD. Marcury |
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Answer» Correct Answer - B Lithium has the lowest density `(0.534 gm cm^(-3)).` |
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| 289. |
The value of X is maximum forA. `MgSO_(4). X H_(2)O`B. `CaSO_(4). X H_(2)O`C. `BaSO_(4).xH_(2)O`D. All have the same value of x |
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Answer» Correct Answer - A `MgSO_(4). 7H_(2)O.` Because of smaller size, `Mg^(2+)` ions are extensively hydrated. |
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| 290. |
Calcium metal is used to produce high vaccum because itA. can remove waterB. can remove both `O_(2) and N_(2)`C. is a good reductantD. is highly electropositive |
| Answer» Correct Answer - B | |
| 291. |
Which of the following is not the use to calcium ?A. Used in chewing gumB. Used to manufacture cementC. Used in manufacture high quality paperD. Used to preserve meat and fish |
| Answer» Correct Answer - D | |
| 292. |
`M+(X+Y)NH_(3) rarr [M(NH_(3))_(x)]^(2+)+ 2[e^(-)(NH_(3))_(4)]^(-)` where M=alkaline earth metal. Value of x is ….. |
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Answer» Correct Answer - 6 |
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| 293. |
Consider the following abbreviations for hydrated alkaline earth metal ions `x=[Be(H_(2)O)_(n)]^(2+),Y=[Mg(H_(2))_(n)]^(2+),Z=[Ca(H_(2)O)_(n)]^(2+` what is the correct order of size of these hydrated alkline metal ions?A. `XgtYgtZ`B. `ZgtYgtX`C. `X=Y=Z`D. `ZgtXgtY` |
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Answer» Correct Answer - 1 |
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| 294. |
The pair of amphoteric hydroxides isA. `AI(OH)_(3),LiOH`B. `Be(OH)_(2),Mg(OH)_(2)`C. `B(OH)_(3),Be(OH)_(2)`D. `Be(OH)_(2),Zn(OH)_(2)` |
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Answer» Correct Answer - D `Be(OH)_(2)//Zn(OH)_(2)` |
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| 295. |
Lithium is strongest reducing agent among alkali metals due to which of the following factor ?A. Ionisation energyB. Electron afficityC. Hydration energyD. Lattice energy |
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Answer» Correct Answer - C Li due to highest hydration energy among the alkali metals in strongest reducing agent. |
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| 296. |
The number of covalent bonds formed by beryllium isA. 2B. 3C. 4D. 5 |
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Answer» Correct Answer - A Since be has two valence electrons, it forms only two covalent bonds. |
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| 297. |
Which is not correctly matched? I) Basic strength of oxides `Cs_(2)OltRb_(2)OltK_(2)OltNa_(2)OltLi_(2)O` II) Stability of peroxides `Na_(2)O_(2)ltK_(2)O_(2)ltRb_(2)O_(2)ltCs_(2)O_(2)` III) Stability of biocarbonate `LiHCO_(3)ltNaHCO_(3)ltKHCO_(3)ltRbHCO_(3)` IV) Melting point `NaFltNaClltNaBrltNaI`A. 1 and 4B. 1 and 3C. 1 and 2D. 2 and 3 |
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Answer» Correct Answer - A |
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| 298. |
Which of the following has correct increasing basic strenght ?A. `MgO lt BeO lt CaO lt BaO`B. `BeO lt MgO lt CaO lt BaO`C. `BaO lt CaO lt MgO lt BeO`D. `CaO lt BaO lt BeO lt MgO` |
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Answer» Correct Answer - B `BeO lt MgO lt CaO lt BaO. ` The basic character of the oxides increases down the group. |
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| 299. |
Assertion: Be and Mg do not impat characteristic colour to the flame. Reason: both Be and Mg have high ionization energy.A. Both assertion and reason are true and reason is the correct explanation of assertionB. Both assertion and reason are true but reason is not the correct explanation of assertionC. Assertion is ture but reason is falseD. But assertion and reason are false |
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Answer» Correct Answer - A Due to high ionisation energy Be and Mg are not excited by the flame. |
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| 300. |
Compolete the following equations : (i) `Na_(2)O_92)+ 2H_(2) O to (W) +H_(2)O_(2)` (ii) `2KO_(2)+2H_(2)O to (X) +(Y) +O_(2)` (iii) `Na_(2) O+ CO_(2)to (Z).`A. `{:(W, X , Y , Z) , (4Na , K_(2)O , H_(2)O_(2) , Na_(2)CO_(3)):}`B. `{:(W, X , Y , Z) , (4Na , K_(2)O , H_(2)O_(2) , Na_(2)CO_(3)):}`C. `{:(W, X , Y , Z) , (4NaOH , 2KOH , H_(2)O , Na_(2)O_(2)):}`D. `{:(W, X , Y , Z) , (2NaOH , 2KOH , H_(2)O_(2) , Na_(2)CO_(3)):}` |
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Answer» Correct Answer - D `Na_(2)O_(2)+ 2H_(2)O to underset((W))(2NaOH)+ H_(2)O_(2)` `2KO_(2)+ 2H_(2)O to underset((X))(2KOH)+ underset((Y))(H_(2)O_(2))+ O_(2)` `Na_(2) O+CO_(2) to underset((Z))(Na_(2) CO_(3))` |
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