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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. |
How many orbitals are singly occupied in `O_(2)` molecule ?A. 2B. 1C. 3D. 4 |
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Answer» Correct Answer - A M.O. configuration of `O_(2)` : `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(sigma2p_(z)^(2))(pi2p_(x)^(2) = pi 2p_(y)^(2))(pi^(**)2p_(x)^91) = pi^(**) 2p_(y)^(1))` |
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| 252. |
Which of the following species is paramagnetic in nature ?A. `H_(2)`B. `Li_(2)`C. `B_(2)`D. `N_(2)` |
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Answer» Correct Answer - C `B_(2)` molecule has the following configuration : `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(pi 2p_(x)^(1)=pi2p_(y)^(1))` |
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| 253. |
Which of the following molecular orbital has the lowest energy ?A. `sigma2p_z`B. `sigma^** 2p_z`C. `pi^** 2p_x`D. `pi^** 2p_y` |
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Answer» Correct Answer - A Energy of bonding orbital is less than antibonding orbitals |
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| 254. |
Which among the following molecules is not flat?A. `C_6H_6`B. `C_2H_4`C. `SO_3`D. `C_2H_6` |
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Answer» Correct Answer - A Ethane `(C_2H_6)` molecule exhibits tetrahedral geometry (three dimensional structure). |
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| 255. |
Which of the following does not contain a coordinate bond?A. `H_(3)O^(+)`B. `BF_(4)^(-)`C. `HF_(2)^(-)`D. `NH_(4)^(+)` |
| Answer» (c) Among the given, only `HF_(2)^(-)` has H-bonding `[F-H…..F]^(-)` Rest all the molecules have coordinate bonds. | |
| 256. |
Which of the following is isoelectronic with carbon?A. `Na^(+)`B. `Al^(3)`C. `O_(2-)`D. `N^(+)` |
| Answer» (d) `thereforeN^(star)(7-1=6e^(-))` is isoelectronic with C as both have 6 electrons. | |
| 257. |
Which of the following diatomic species gets stabilised by losing an electronA. `O_2`B. `N_2`C. `O_2`D. `CN^-` |
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Answer» Correct Answer - A `O_2` loses electron from the antibonding MO, hence it gets stabilised after losing an electron |
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| 258. |
Non-bonding orbitals haveA. same energy as the atomic orbitals from which they are formedB. more energy than the atomic orbitals of the highest energy from which they are formedC. less energy than the atomic orbitals of the lowest energy from which they are formedD. none of these. |
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Answer» Correct Answer - A Non-bonding orbitals have same energy as the atomic orbitals from which they are formed |
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| 259. |
Which of the following has a linear structure?A. `C Cl_(4)`B. `SO_(4)`C. `C_(2)H_(2)`D. `C_(2)H_(4)` |
| Answer» (c ) `C_(2)H_(2)` has linear structure. | |
| 260. |
in compound `X` all the bond angles around central atom are `109^(@)28^(@)` one of the following will be `X` ? .A. ChloromethaneB. IodoformC. Carbon tetrachlorideD. Chloroform |
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Answer» Correct Answer - C Compound is carbotetrachloride because `C Cl_(4)` has `sp^(3)`- hybridization 4 orbitals giving regular tetrahedron geometry. In others the geometry is little distorted inspite of `Sp^(3)` hybridization due to different atoms on the vertices of tetrahedron |
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| 261. |
In compounds of type `ECl_3` where `E= B, P, As, Bi`. The angles `Cl - E -C l` for different `E` are in the order :A. `BgtP=As=Bi`B. `BgtPgtAsgtBi`C. `BltP=As=Bi`D. `BltPltAsltBi` |
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Answer» Correct Answer - b |
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| 262. |
Which one of the following is the correct statementA. `O_2` molecule has bond order 2 and is diamagneticB. `N_2` molecule has bond order 3 and is paramagneticC. `H_2` molecule has bond order zero and is diamagneticD. `C_2` molecule has bond order 2 and is diamagnetic |
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Answer» Correct Answer - D `O_2`: BO =2 but not diamagnetic `N_2` : BO = 3 but not paramagnetic `H_2`:BO = 1 but not zero `C_2 : K K sigma_(2s)^2 sigma_(2s)^(2**)pi_(2px)^(2)pi_(2py)^(2)` BO =`1/2`(6-2)=2 and it diamagnetic `He_2^(+)`=BO=`1/2` and not zero |
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| 263. |
Which of the following pairs is isostractural (i.e having the same shape and hybridization ?A. `[BCl_(3) "and " BrCl_(3)]`B. `[NH_(3)"and" NO_(3)^(-)]`C. `[NF_(3) " and " BF_(3)]`D. `[BF_(4)^(-) "and " NH_(4)^(+)]` |
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Answer» Correct Answer - D `BF_(4)^(-)` hybridization `sp^(3)`, tetrahedral structure. `NH_(4)^(+)` hybridization `sp^(3)`, tetrahedral structure. |
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| 264. |
Which of the following pairs is isostractural (i.e having the same shape and hybridization ?A. `BCl3` and `BrCl_3`B. `NH_3` and `NO_3^-`C. `NF_3` and `BF_3`D. `BF_4^-` and `NH_4^(3+)` |
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Answer» Correct Answer - D `BF_4^(-)` as well as `NH_4^(+)` ions have tetrahedra structure |
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| 265. |
Which of the following has giant convalent structure ?A. NaClB. `SiO_(2)`C. `AlCl_(3)`D. `PhO_(2)` |
| Answer» Correct Answer - (b) | |
| 266. |
Which one of the following constitutes a group of the is electronic species ?A. `C_2^(2-) , O_2^-, CO, NO`B. `No^+ ,C_2^(2-) , CN^-, N^_2`C. ` CN^- , N_2 , O_2^(2-) , C_2^(2-)`D. ` N_2 , O_2^- , NO^+ CO` |
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Answer» Correct Answer - B ` NO^+ , C_2^(2-) CN^(-) ` and ` N_2` all have `14` electrons. |
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| 267. |
In which of the following molecules all the bonds are not equal ?A. `AlF_3`B. `NF_3`C. `CIF_3`D. `BF_3` |
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Answer» Correct Answer - A `SN` of `Cl` in `CIF_3` is `3+2=5`. Thus, it has triagonal bipyramidal geometry and is T-shaped. It has axial bonds and equatorial bonds. Axial bonds are slightly longer. |
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| 268. |
Which of the following is not isostructural with `SiCkl_4` ?A. `PO_4^(3-)`B. `NH_4^(+1)`C. `SO_2^`D. `SO_4^(2-)` |
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Answer» Correct Answer - C S in `SCl_4` is `sp^3` d-byridised nad possesses see -saw structure with one lone pair on axial position ` SiCl_4` is tetrahedral. . |
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| 269. |
Which one of the following pairs of species have the same bond order ?A. `CN^- ` and ` NO^+`B. `CN^-` and ` CN^+`C. ` O_2^-` and `CN^-`D. ` NO^+` and `CN^+` |
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Answer» Correct Answer - A `CN^(-)` and `NO^(+)` are isoelectronic `14` and have same bond order . |
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| 270. |
The charge /size ratio of a cation dermines its polarizing power. Which one of the following sequences represents the increasing order of the polarixing power of the cationic species , `K^+ , Ca^+ , Mg^(2+), Be^(2+)` ?A. ` Mg^(2+) lt Be^(2+) lt K^+ lt Ca^(2+)`B. `Be^(2+) lt K^+ lt Ca^(2+) lt Mg^(2+)`C. `K^+ lt Ca^(2+) lt Mg^(2+) lt Be ^(2+)`D. `Ca^(2+) lt Mg^(2+) lt be^(2+) lt K^(+)` |
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Answer» Correct Answer - C Higher the charge`//`size ratio , more is the polarizing power . `:. k^(+) lt Ca^(2+) lt Mg^(2+) lt Be^( 2+)` . |
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| 271. |
Which of the following species has a linear shape ?A. `NO_2^(+)`B. `O_3`C. `NO_2^(-)`D. `SO_2` |
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Answer» Correct Answer - C `SN` of `N` in `NO_2^(+)` is `2+0=0` (linear), `SN` of `O` in `O_3` is `2+1=3` (bent), `SN` of `N` in `NO_2^(-)` is `2+1=3` (bent), and `SN` of `S` in `SO_2` is `2+1=3` (bent). |
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| 272. |
Which of the following species has a linear shape ?A. `NO_2^+`B. `O_3`C. `NO_3^-`D. `SO_2` |
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Answer» Correct Answer - A `O=overset (+)(N)=O,N` has no lone pair. |
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| 273. |
Linus Pauling received the Nobel Prize for his work onA. atomic structureB. photosynthesisC. chemical bondsD. thermodynamics |
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Answer» Correct Answer - C Linus Pauling contributed to chemical bonding, so, he received the Nobel Prize for this work in chemical bonding. |
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| 274. |
Among the following orbital bonds, the angle is minimum betweenA. `sp^3` bondB. `p_x and p_y` -orbitalsC. H-O-H in waterD. sp bonds |
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Answer» Correct Answer - B When `p_x` and `p_y` form bond, then the bond angle is minimum and it is only `90^@`. NOTE Bond angle in `sp^3` bonds, H-O-H in water and in sp bonds are `109^@28, 180^@` and `180^@` respectively. |
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| 275. |
Of the following sets ,which one does not contain isoeletronic species ?A. `PO_4^(3-), SO_4^(2-), ClO_4^-`B. `CN^-, N_2, C_2^(2-)`C. `SO_3^(2-),CO_3^(2-), NO_3^-`D. `BO_3^(3-), CO_3^(2-), NO_3^-` |
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Answer» Correct Answer - C (A) `PO_4^(3-)` (No. of electrons = 15+8 x 4+3=50) `SO_4^(2-)` (No. of electrons= 16+8 x 4+2=50) `ClO_4^(-)` (No. of electrons = 17 + 8 x 4 + 1 = 50) (B) `CN^(-)` (No. of electrons = 6 + 7 + 1 = 14) `N_2` (No. of electrons=2 x 7= 14) `C_2^(2-)` (No. of electrons=2 x 6 +2 =14 ) (C) `SO_3^(2-)` (No. of electrons=16 + 3 x 8 + 2 = 42) `CO_3^(2-)` (No. of electrons =6+8 x 3 +2=32) `NO_3^(-)` (No. of electrons = 7+8 x 3+1 = 32) (D) `BO_3^(3-), CO_3^(2-), NO_3^(-)` (Each of these ions have 32 electrons each) Thus `SO_3^(2-), CO_3^(2-)` and `NO_3^(-)` are not isoelectronic. |
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| 276. |
Find the bond order of ` CO`A. 2B. 2.5C. 3D. 3.5 |
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Answer» Correct Answer - C `BF_3` has planar symmetrical trigonal structure in which dipole moments of 3B-F bonds cancel each other and net dipole moment is zero |
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| 277. |
Some of the properies of the two species `NO_(2)^(-)` and `H_(3)O` are described below which one of them is correct ?A. Dissimilar in hybridization for the central atom with different structuresB. Isostructural with same hybridization for the central atomC. Isostructural with different hybridization for the central atomD. Similar in hybridization for the central atom with different structures. |
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Answer» Correct Answer - A `NO_3^(-)` ion has a planar structure and nitrogen atom in it is `sp^2` hybridised whereas in `H_3^(+)O` central oxygen atom is `sp^3` hybridised and `H_3^(+)O` has tetrahedral structure |
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| 278. |
For the two compounds, the vapour pressure of (i) at a particular temperature is expected to be A. higher than (i)B. lower than that of (i)C. same as that of (i)D. can be higher or lower depending upon the size of the vessel. |
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Answer» Correct Answer - A In B, intramolecular H-bonding will occur while in A, intermolecular H-bonding will occur. Thus, interparticle forces (H-Bonds) are stronger in A |
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| 279. |
Which carbon is more electronegative ?A. `sp^3` hybridised carbonB. sp hybridised carbonC. `sp^2` hybridised carbonD. The electron attracting power of C is always same irrespective of its hybrid state. |
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Answer» Correct Answer - B Due to greatest percentage of s-character |
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| 280. |
The species having octahedral shape is :A. `SF_6`B. `BF_4^(-)`C. `PCl_5`D. `BO_3^(3-)` |
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Answer» Correct Answer - A `S` atom in ` SF_6` has ` sp^3 d^2` -hybridsation leading to octahedral shape . |
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| 281. |
The energy of `sigma_(2x)`, is greater than that of `sigma_(1s)^**` orbital becauseA. `sigma_(2s)` orbital is formed only after `1s`B. `sigma_(2s)` orbital is bigger than `sigma_(1s)` orbitalC. `sigma_(2s)` orbital has a greater value of `n` than `sigma_(1s)^**`D. `sigma_(2s)` is a bonding orbital while `sigma_(2x)^**` is an antibonding orbital. |
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Answer» Correct Answer - C Although the antibonding orbital `(sigma_(1s)^**)` has higher energy and is, thus, less stable than the bonding orbitals `(sigma_(1s))`, but this antibonding orbital has greater stability than the bonding orbital `(sigma_(2s))` because the energy of an MO increases as the value of the principal quantum number `(n)` increases. This simply reminds us that the concepts of stability and energy applied here are relative. |
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| 282. |
Which of the following having plane of symmetry ?A. `H_(2)SO_(4)`B. `H_(2)O`C. `HNO_(3)`D. `C Cl_(4)` |
| Answer» Correct Answer - C | |
| 283. |
Which has the lowest boiling point?A. `NH_3`B. `PH_3`C. `AsH_3`D. `SbH_3` |
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Answer» Correct Answer - B The order of decrease in B.pl. is `NH_3 gt SbH_3 AsH_3 gt PH_3`. Ammonia has highest b.pt. due to H-bonding. Greater size of Sb and As in comparison to P, makes the boiling of their hydrides more than that of `PH_3`. |
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| 284. |
The d-orbitals involved in `sp^(3)d` hybridisation is:A. `d_(x^(2)-y^(2))`B. `d_(xy) `C. `d_(z^(2))`D. `d_(zx)` |
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Answer» Correct Answer - C `dsp^(3) ` or `sp^(3)d` one `s^(+)` three `p^(+)` one d(`d_(z^(2))`) |
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| 285. |
Which of the following compounds has `sp^(2)`-hybridisation?A. `CO_(2)`B. `SO_(2)`C. `N_(2)O`D. `CO` |
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Answer» Correct Answer - b |
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| 286. |
`sp^2`-hybridisation is involved in the molecule ofA. pyramidalB. tetrahedralC. octahedralD. trigonal planar |
| Answer» Correct Answer - D | |
| 287. |
Stability of the species `Li_(2), Li_(2)^(-), Li_(2)^(+)` increases in the order ofA. `Li_ 2 lt Li_2^(+) lt Li_2^(-)`B. `Li_2^(-) lt Li_2 lt Li_2^(+)`C. `Li_2 lt Li_2^(-) lt Li_2^(+)`D. `Li_2^(-) lt Li_2^(+) lt Li_2` |
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Answer» Correct Answer - D Atomic number of Li is 3. Thus, the total number of electrons in `Li_2` is 6. `Li_2(6)sigma1s^2sigma^**1s^2sigma2s^2` Bond order `=(N_b-N_a)/(2)=(4-2)/(2)=1` `Li_2^(+)` is formed by the loss of one `e^(-)` from `sigma2s` molecular orbital. `Li_2^(+)(5)sigma1s^2sigma^**2s^2sigma2s^1` Bond order `=(N_b-N_a)/(2)=(3-2)/(2)=0.5` `Li_2^(-)` is formed by the gain of one `e^(-)` into `sigma^**2s` orbital. `Li_2^(-)(7)=(N_b-N_a)/(2)=(4-3)/(2)=0.5` Both `Li_2^(+)` and `Li_2^(-)` have identical bond orders but `Li_2^(+)` is more stable than `Li_2^(-)` because `Li_2^(-)` has more antibonding electrons. (Note that antibonding influence is greater than bonding influence.) Thus, the correct order is `Li_2^(-) lt Li_2^(+) lt Li_2` |
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| 288. |
Which are isostructural species ?A. `CH_3^- ` and ` CH_3^+`B. `NH_4^+` and `NH_3`C. `SO_4^(2-)` and ` BF_4^(-)`D. `NH_2^-` and `BeF_2` |
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Answer» Correct Answer - C Both are terahedral in nature . |
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| 289. |
Match the list I and list II and write the correct matching A. A-2,B-1,C-3,D-5,E-4B. A-1,B-5,C-2,D-3,E-4C. A-5,B-1,C-2,D-3,E-4D. A-1,B-5,C-2,D-3,E-2 |
| Answer» Correct Answer - C | |
| 290. |
All carbon atoms are `sp^(2)`-hybridised in:A. 1,3-butadieneB. `CH_(2)=C=CH_(2)`C. CyclohexaneD. 2-butene |
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Answer» Correct Answer - A `underset("1,3 -butadiene")(overset(sp^(2))(CH_(2))=overset(sp^(2))(C)H-overset(sp^(2))(C)H =overset(sp^(2))(C)H_(2))` |
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| 291. |
The incorrectly matched pair, among the following isA. `{:("Molecules",,"Shape"),(BrF_(5),,"Trigonal bipyramidal"):}`B. `{:("Molecules",,"Shape"),(SF_(4),,"See Saw"):}`C. `{:("Molecules",,"Shape"),(ClF_(3),,"T-shape"):}`D. `{:("Molecules",,"Shape"),(NH_4^(+),,"Tetrahedral"):}` |
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Answer» Correct Answer - A `BrF_(5)` has square pyramidal shape. |
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| 292. |
The bond angle in `H_2S` isA. gt `NH_3`B. Same as in `BeCl_2`C. gt `H_2Se`, lt `H_2O`D. Same as in `CH_4` |
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Answer» Correct Answer - C Bond angle of hydrides of group 16 elements are `H_2O gt H_2S gt H_2Se gt H_2Te` |
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| 293. |
The dye acriflavine when dissolved in water has its maximum light absorption at 4530 Ã… and has maximum fluorescence emission at 5080 Ã…. The number of fluorescence quantum is, on the average, 53% of the number of quanta absorbed. What percentage of absorbed light energy is emitted as fluorescence?A. `41%`B. `47%`C. `74%`D. `63%` |
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Answer» Correct Answer - B Energy of each photon absorbed `E=hv=(hv)/lambda` `E=(6.63xx10^(-34)Js xx 3 xx 10^8 m//s)/(4530xx10^(-10)m)` `=4.39xx10^(-19)` J Energy of each photon emitted E=hv=`(hv)/lambda` `=(6.63xx10^(-34)Js xx 3 xx 10^8 m//s)/(5080xx10^(-10)m)` `=3.92xx10^(-19)` J Energy fraction emitted `=(0.53(3.92xx10^(-19)))/(4.39xx10^(-19))xx100=47%` |
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| 294. |
The dielectric constant of `H_(2)O` is 80. The electrostatic force of attraction between `Na^(+)` and `Cl^(-)` will beA. reduced to `1/40` in water than in airB. reduced to `1/80` in water than in airC. will be increased to 80 in water than in airD. will remain unchanged |
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Answer» Correct Answer - B Water is a polar solvent and have dielectric constant 80.As NaCl is a polar compound and like dissolves like so, forces of attraction between `Na^+` and `Cl^-` ion will reduce to `1/80` in water. |
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| 295. |
In the compound `overset (1)(C ) H_2 = overset (2)(C)H-overset (3)(C )H_2-overset (4)(CH_2) -overset(5)(C)-=overset (6)(C )H` the `overset (2) (C ) -overset (3)(C)` bond is of the type :A. ` sp -sp^2`B. ` sp^3 -sp^3`C. ` sp-sp^3`D. ` sp^2 -sp^3` |
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Answer» Correct Answer - D `underset(sp^2)overset(1)(C)H_2=underset(sp^2) overset(2)(C)H-underset(sp^3)overset(3)(C)H_2-underset(sp^3)overset(4)(C)H_2-underset(sp)overset(5)(C)-=underset(sp)overset(6)(C)H`. |
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| 296. |
The statement true for `N_(3)^(-)` isA. it has a nonlinear structureB. it is called a pseudohalogenC. the formal oxidation state of nitrogen in this anion is `-1`D. it is isoelectronic with `NO_2` |
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Answer» Correct Answer - B::C The azide ion `(N_3^(-))` has 16 valence electrons and is isoelectronic with `CO_2`. The `N_3^(-)` ion is linear `(N-N-N)` like `CO_2` molecule. The formal oxidation state of nitrogen in this anion is `-1`, because the net charge on the ion is `-1` as shown in the following resonating structures. `:overset(2-)overset(..)underset(..)N-overset(+)N-=overset(..)Nharroverset(..)N-=overset(+)N-overset(2-)overset(..)underset(..)N:harr:overset(1-)overset(..)N=overset(+)N=overset(1-)overset(..)N:` The `(N_3)^(-)` ion is considered as a pseudohalide ion. It forms the extremely unstable and explosive compounds as fluorazide `FN_3`, chlorazide `CIN_3`, bromazide `BrN_3` and iodazide `IN_3`, but the dimer `N_3-N_3` is unknown. |
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| 297. |
Among the following the pair in which the two species are not isostuctural isA. `SiF_4` and `SF_4`B. `IO_3^(-)` and `XeO_3`C. `BH_4^(-)` and `BH_4^(+)`D. `PF_6^(-)` and `SF_6` |
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Answer» Correct Answer - A Isostructural here means identical shape and geometry. In `SiF_4`, the steric number of `Si` is `4` (four F atoms bonded + zero lone pair). Thus, `SiF_4` has tetrahedral shape and tetrahedral geometry. In `SF_4`, the steric number of `S` is `5` (four F atoms bonded + one lone pair). Thus, `SF_4` has trigonal bipyramidal geometry but seesaw shape. |
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| 298. |
If `N_(x)` is the number of bonding orbitals of an atom and `N_y` is the number of antibonding orbitals, then the molecule/atom will be stable ifA. `N_(x) gt N_(y)`B. `N_(x)=N_(y)`C. `N_(x) lt N_(y)`D. `N_(x) le N_(y)` |
| Answer» Correct Answer - A | |
| 299. |
Which of the following species has tetrahedral geometry?A. `BH_(4)^(-)`B. `NH_(2)^(-)`C. `CO_(3)^(2-)`D. `H_(3)O^(+)` |
| Answer» (a) `BH_(4)^(-)` has tetrahedral geometry. | |
| 300. |
London Dispersion force is present between :-A. Polar + Polar moleculesB. Nonpolar + Non-polar moleculesC. Polar+ Nonpolar moleculesD. Ionic |
| Answer» Correct Answer - B | |