InterviewSolution
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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.
| 201. |
Which of the following is not true for the beryllium halides ?A. They are covalent.B. They are hygroscopic and fume in air.C. They sublime.D. They conduct electricity. |
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Answer» Correct Answer - D Being covalent,t hey are soluble in organic slvents and do not conduct electricity. Due to hydrolysis, they fume in air. `BeCl_(2)+2H_(2)OtoBe(OH)_(2)+2HCl` |
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| 202. |
The order of decreasing ionisation ethalpy in alkali metals isA. `Na gt Li gt K gt Rb`B. `Rb lt Na lt K lt Li`C. `Li gt Na gt K gt Rb`D. `K lt Li lt Na lt Rb` |
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Answer» Correct Answer - C Ionisation enthalpy of alkali metals decreases down the group from Li to Cs. This is because of increase in size which outweighs the increasing nuclear charge, and the outermost electron is very well screened from the nuclear charge. |
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| 203. |
Match the following |
| Answer» Correct Answer - A::B::C::D | |
| 204. |
Match the following |
| Answer» Correct Answer - A::B::C::D | |
| 205. |
Match the following |
| Answer» Correct Answer - A::B::C::D | |
| 206. |
The number of water of crystallisation in hypo are____. |
| Answer» Correct Answer - 5 | |
| 207. |
How many groups belong to the s-block of the periodic table ? |
| Answer» Correct Answer - 2 groups | |
| 208. |
How many electrons can be accommodated in the s-orbital? |
| Answer» Correct Answer - 2 electrons | |
| 209. |
Which of the following is not the point of difference between Be and other alkline earth metals?A. It has a tendency to form covalent bonds.B. It dissolves in alkalies with evolution of hydrogenC. Its oxides and hydroxides are amphoteric.D. its carbide gives acetylene on hydrolysis. |
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Answer» Correct Answer - D `Be_(2)C` gives methane on hydrolysis while other Carbides gives acetylene. `Be_(2)C+4H_(2)Oto2Be(OH)_(2)+CH_(4)` |
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| 210. |
Which of the following does not show diagonal relationship between beryllium and aluminium?A. Both BeO and `Al_(2)O_(3)` are amphoteric in nature.B. Both beryllium and aluminium form polymeric covalent hydrides.C. Both beryllium and aluminium form nitrides with nitrogen which evolve `NH_(3)` with water.D. Both metal carbonates are highly stable. |
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Answer» Correct Answer - D The carbonates of both the metals are unstable. |
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| 211. |
Beryllium shows a diagonal relationship withA. calciumB. boronC. aluminiumD. magnesium |
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Answer» Correct Answer - C Just as Li shows resemblance with its diagonally opposite element Al. This is because the two elements have the same electronegativity (be=1.5,Al=1.5) and possess similar polarizing power (i.e., charge/radius). |
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| 212. |
Beryllium shows diagonal relationship with aluminium. Which of the following similarly is incorrect?A. `Be_(2)C` like `Al_(4)C_(3)` yields methane on hydrolysisB. Be like Al is rendered passive by `HNO_(3)`C. `Be(OH)_(2)` like `Al(OH)_(3)` is basicD. Be forms beryllates and Al forms aluminates. |
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Answer» Correct Answer - C Both `Be(OH)_(2) and Al(OH)_(3)` are amphoteric in nature. |
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| 213. |
Assertion: Be is readily attacked by acids. Reason: Be shows diagonal relationship to Na.A. If both assertion and reason are true and reason is the correct explanation of assertionB. If both assertion and reason are true but reason is not the correct explanation of assertionC. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - D Be shows diagonal relationship to Al, and is not readily attacked by acids because of presence of an oxide film on the surace of the metal. |
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| 214. |
The similarity between Li to group 1 and Mg of group 2 is called a diagonal relation. It arises becauseA. Li and Mg atoms have similar sizesB. Li ad Mg ions have similar sizesC. Li and Mg have similar sizesD. all of these |
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Answer» Correct Answer - D On descending a group, the atoms and ions increase in size. On moving from left to right in the periodic table, the size decreases. Thus, on moving diagonally, the size reains nearly the same: `r(Li)=152pm,r(Mg)=160pm` `r(Li^(+))=76pm,r(Mg^(2+))=72pm` Similarly, on moving diagonally, the electrongetivities remains nearly the same. `{:(Li,Be),(1.0,1.5),(Na,Mg),(0.9,1.2):}` |
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| 215. |
Which of the following compounds contains both magnesium and silicon as constituents ?A. MicasB. TalcC. OlivineD. All of these |
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Answer» Correct Answer - D Mg occurs in a wide range of silicate minerals , olivine `(Mg,Fe)_(2)SiO_(4), " talc " Mg_(3)(OH)_(2)Si_(4)O_(10), " chrysotile " Mg_(3)(OH)_(4)Si_(2)O_(5) (" asbestos "), " and micas such as " K^(+)[Mg_(3)(OH)_(2)AISi_(3)O_(10)]^(-)`. |
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| 216. |
Kieserite is an ore ofA. KB. CaC. MgD. Na |
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Answer» Correct Answer - C Kieserite is the sulphate ore of `Mg: MgSO_(4).H_(2)O. " Epsomite is " MgSO_(4).7H_(2)O` |
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| 217. |
A solution of `MgCl_(2)` in water has pHA. `lt7`B. `gt7`C. 7D. 14.2 |
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Answer» Correct Answer - A `MgCl_(2)` is a salt of weak base `[Mg(OH)_(2)]` and strong acid (HCl). Therefore, it undergoes cationic hydrolysis to give an acidic solution having `pHlt7`. `Mg^(2+)+2H-OHrarrMh(OH)_(2)+2H^(+)` Magnesium hydroxide is almost completely insoluble in water. |
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| 218. |
Anhydrous magnesium chloride can be prepared by heating `MgCl_(2)6H_(2)O`A. in an atmosphere of nitrogenB. in a current of dry HCl gasC. with magnesiumD. with concentrated HCl |
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Answer» Correct Answer - B The presence of hydrogen chloride suppresses the hydrolysis of magnesium chloride by its water of crystalization. |
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| 219. |
Write one use of cement. |
| Answer» It is used in concrete and reinforced concrete. | |
| 220. |
Write two uses of calcium carbonate. |
| Answer» It is used as building material in the form of marble and with magnesium it is used as flux in extraction of iron. | |
| 221. |
`Ca^(2+)` is isoelectronic withA. `Na`B. `Mg^(2+)`C. `Ba^(2+)`D. Ar |
| Answer» Correct Answer - D | |
| 222. |
`RbO_(2)` is aA. peroxide and diamagneticB. superoxide and paramagneticC. superoxide and diamagneticD. peroxide and paramagnetic |
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Answer» Correct Answer - B Rubindium surepoxide `(RbO_(2))` contains superoxide ion `(O_(2)^(-))` which contains one upaired electron in the antibondingmolecular orbital. This makes `RbO_(2)` paramagnetic. |
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| 223. |
What happens when `CaCO_(3)` reacts with dilute acid? |
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Answer» It reacts with dilute acid to liberate carbon dioxide. `CaCO_(3)+2HCl to CaCl_(2)+H_(2)O+CO_(2)` `CaCO_(3)+H_(2)SO_(4)toCaSO_(4)+H_(2)O+CO_(2)`. |
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| 224. |
K, Rb and Cs form which type of compounds with oxygen? |
| Answer» Correct Answer - superoxide | |
| 225. |
Write two reasons behind the anomalous behaviour of first element of each group. |
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Answer» (i) Smaller size of the atom as compared to other members. (ii) The ionization enthalpies of first element is higher than that of the other members. |
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| 226. |
What are oxo-acids? |
| Answer» Oxo acids are those acids in which the acidic proton is on a hydroxyl group with an oxo-group attached to the same atom. | |
| 227. |
The following two figures represent A. (i) `BeCl_(2)` is a dimer in vapour phase, (ii) `BeCl_(2)` is chain structure in solid stateB. (i) `BeCl_(2)` is solid state, (ii) `BeCl_(2)` is in vapour phaseC. (i) `BeCl_(2)` is monomer in solid state, (ii) `BeCl_(2)` is linear polymer in vapour phaseD. (i) `BeCl_(2)` is linear monomer, (ii) `BeCl_(2)` is three dimensional dimer |
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Answer» Correct Answer - A (i) is a dimer of `BeCl_(2)` is vapour phase. (ii) is a chain structure of `BeCl_(2)` is solid state. |
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| 228. |
When `BeCl_(2)` is hydrolysed, white fumes of gas are given out. The intensity of fumesintensifies when a rod dipped in moist ammonia is brought near the mouth of the test tube. The gas which comes out during hydrolysis isA. `Cl_(2)`B. `HCl`C. `NH_(4)OH`D. `NH_(4)Cl` |
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Answer» Correct Answer - B `BeCl_(2)+2H_(2)O to Be(OH)_(2)+ underset(("fumes"))(2HCl)HCl+NH_(3) to underset(("intense fumes"))(NH_(4)Cl)` |
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| 229. |
A solution of a compound X in dilute HCl on treatment with a solution of `BaCl_(2)` gives a white precipitate of compound Y which is insoluble in conc. `HNO_(3)` and and conc. `HCl`. Compound X imparts golden yellow colour to the flame. `underset(("immparts golden yellow colour"))(X("Solution in dilute HCl"))+BaCl_(2) to underset("White")(Y)underset("Conc. HCl")overset("Conc. "HNO_(3))to`Insoluble What are compounds X and Y?A. X is `MgCl_(2)` and Y is `BaSO_(4)`B. X is `CaCl_(2) and Y` is `BaSO_(4)`C. X is `Na_(2)SO_(4)` and Y is `BaSO_(4)`D. X is `MgSO_(4)` and Y is `BaSO_(4)` |
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Answer» Correct Answer - C `underset((X))(Na_(2)SO_(4))+BaCl_(2) to underset((Y))(BaSO_(4))+2NaCl` |
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| 230. |
The solubility of most salts depends on the lattice energy of the solid and the hydration energy of the ions. On descending the group, the hydration energy decreases more rapidly than the lattice energy, hence the compound become less soluble as the metals gets larger. however, with the fluorides and hydroxides and the lattice energy decreases more rapidly than the hydration energy and so their solubility increases on descending the group. Q. The most soluble hydroxide will beA. `Mg(OH)_(2)`B. `Ca(OH)_(2)`C. `Sr(OH)_(2)`D. `Ba(OH)_(2)` |
| Answer» Correct Answer - D | |
| 231. |
Which of the chloride shows least solubility in water?A. LiClB. NaClC. KClD. RbCl |
| Answer» Correct Answer - C | |
| 232. |
Order of lattice enthalpy is asA. `BeF_(2) gt MgF_(2) gt CaF_(2) gt SrF_(2)`B. `BeF_(2) lt MgF_(2) lt CaF_(2) lt SrF_(2)`C. `LiF lt LiCl lt LiBr lt Lil`D. `Lil lt LiBr lt CsBr lt Csl` |
| Answer» Correct Answer - A | |
| 233. |
Which of the following I a correct statement?A. The firstand second ionization enthalpies of group elementsare greater than those of group 1 elementsB. the first and second ionization enthalpies of group elementsare smaller than those of group 1 elementsC. the first ionization enthalpy of group 2 element greater but he second ionization enthalpy issmall than those of group 1 elements.D. The first ionization enthalpy of group 2 elements smaller but the seconds but the seconds ionization enthalpy is greater that those of group 1 elements. |
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Answer» Correct Answer - C As such, group 2 elements (like group 1 elements) possesslow ionization enethalpies on account of relatively smaller nuclear charge andrealtively larger atomic size. The first ionization enthalpies of group 2 elements are greater than those of group 1 elements because of increased effective than those of group 1 elements because of increased effective nuclear charge in addition to decreased atomic size. However, the second ionization enthalpies of group 2 elements are smaller than those of group 1 elements because after the loss of second electron, they acquire stable configuration of the nearest noble gas while alkali metals already possess noble gas configuration after the loss of first electron. The third ionization enthalpies of group 2 elements are very high and greater than those of group 1 elements. |
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| 234. |
Which of the following ions has the maximum hyration enthalpy?A. `Be^(2+)`B. `Mg^(2+)`C. `Ca^(2+)`D. `Sr^(2+)` |
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Answer» Correct Answer - A Like alkali metal ions,the hydration enthalpies of alkaline earth metal ions decrease withh increase in ionic size down te group: `Be^(2+) gt Mg^(2+) gt Ca^(2+) gt Sr^(2+) gt Ba^(2+)` |
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| 235. |
Why first ionization energy of alkaline earth metals is higher than that of alkali metals? |
| Answer» This is due to their smaller size as compared to the corresponding alkali metal. | |
| 236. |
The second ionization enthalpies `(Delta_(i)H_(2))` of alkali metals areA. very lowB. lowC. highD. very high |
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Answer» Correct Answer - D Because the electron is to be knocked off from the noble gas electronic configuration of unipositive ions. |
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| 237. |
Which of the following has the lowest first ionization thalpy?A. CaB. SrC. BaD. Ra |
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Answer» Correct Answer - C Down the group, ionization enthalpy decreases on account of increase of size. However, Ra has slightly higher first ionization enthalpy relative to Ba on ccount of the presence of poor sheilding 4 f electrons. The same is true for its 2nd ionization enthalpy. |
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| 238. |
Why does ionization energy decreases down the group? |
| Answer» Because the attractive force of nucleus on electrons of outermost cell decreases down the group. Therefore ionization becomes easier. | |
| 239. |
A metal M reaccts with nitrogen to give nitride which on reaction with water produces ammonia gas. Metal M can beA. NaB. KC. LiD. Rb |
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Answer» Correct Answer - C `6Li+N_(2) overset(Delta)to 2Li_(3)N` `Li_(3)N+3H_(2)Oto3LiOH+NH_(3)` |
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| 240. |
What colour is imparted by Rubidium in flame test? |
| Answer» Correct Answer - Red violet. | |
| 241. |
One mole of magnesium nitride on reaction with an excess of water givesA. two moles of ammoniaB. two moles of nitric acidC. one mole of nitric acidD. one mole of ammonia |
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Answer» Correct Answer - A It is a case of hydrolysis: `(Mg^(2+))_(3)(N^(3-))_(2)+6overset(delta-)H-Ooverset(delta-)Hrarr3Mg(OH)_(2)+2NH_(3)` |
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| 242. |
Sodium and potassium, although so similar chemically, differ qualitatively in theirA. ability to penetrate cell membranesB. transport mechanismsC. efficiency to activate enzymesD. all of these |
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Answer» Correct Answer - D `K^(+)` ions are the most abundant cations within cell fluids. Thus they activate many enzymes and participate in the oxidation of glucose to produce ATP (adenosine triphosphate). |
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| 243. |
Group 2 nitrates are prepared in solution by the action of nitric acid onA. oxidesB. hydroxidesC. carbonatesD. all of these |
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Answer» Correct Answer - D `MO+2HNO_(3)toM(NO_(3))_(2)+H_(2)O` `M(OH)_(2)+2HNO_(3)toM(NO_(3))_(2)+2H_(2)O` `MCO_(3)+2HNO_(3)toM(NO_(3))_(2)+CO_(2)+H_(2)O` |
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| 244. |
Which of the following nitrates crystallizes as anhydroms salt?A. `Be(NO_(3))_(2)`B. `Ba(NO_(3))_(2)`C. `Mg(NO_(3))_(2)`D. `Ca(NO_(3))_(2)` |
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Answer» Correct Answer - D Magnesium nitrate crystallizes with six molecules of water while barium nitrate crystallizes as the anhydrous salt. This again shows that the tendency to form hydrates decreases with increasing size and decreasing hydration enthalpy down the group. |
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| 245. |
Which alkali mettal do not show photoelectric effect? |
| Answer» Correct Answer - Lithium | |
| 246. |
Among potassium and sodium which one is lighter metal? |
| Answer» Correct Answer - Potassium. | |
| 247. |
Which of the alkali metals is lighter than water?A. kB. NaC. LiD. All of these |
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Answer» Correct Answer - D On account of large atoms which are less closely packed, alkali metals have remarkably low densities in coparison to other metals. Li metal is only about half as densities in comparison to other metals. Li metal is only about half as densas water `(0.54g cm^(-3)`, while Na and K are slightly less dense than water (0.97 and 0.86 g `cm^(-3)`). |
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| 248. |
Photoelectric effect is the maximum inA. CsB. NaC. KD. Li |
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Answer» Correct Answer - A Photoelectric effect is the emission of electrons by substances when irradiated with a light of frequency greater than a certain minimum frequency called threshold frequency. It is maximum in Cs as it has the lowest ionization enthalpy. |
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| 249. |
The number and type of bonds between two carbon atoms in `CaC_(2)` are:A. two sigma, two piB. two sigma, one piC. one sigma, two piD. one sigma, one pi |
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Answer» Correct Answer - C Calcium carbide is properly written as `Ca^(2+)(overlineC-=overlineC)` There is a triple bond between two C atoms which consist of one sigma and two pi bonds. |
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| 250. |
Which of the following is the most powerful reducing agent in the gas phase ?A. CsB. LiC. KD. Na |
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Answer» Correct Answer - A The tendency of an element to lose electrons in the gas phase is measured in terms of ionization enthalpy. Lower the `Delta_(i)H`, greater the tendency to lose electrons, stronger the reducing character, and higher the reactivity of the element. Since `Delta_(i)H` decreases down the group, reducing character (or reactivity in the gas phase) increases from Li to Cs : `Li lt Na lt K lt Rb lt Cs`. |
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