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.
| 1. |
The energy required to stop ejection of electrons from a Cu plate is `0.24` eV.Calculate the work function Cu when a radiation of wavelength `lambda = 250` nm strikes the plate.A. 24.3 eVB. 24 eVC. 4.65 eVD. 4.95 eV |
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Answer» Correct Answer - B Energy of Photon =work function + K.E. =work function + `eV_0`…(1) where e=electronic charge `V_0`=Stopping potential and `eV_0` is equal to energy required to stop ejection of electron. E/photon =hc/`lambda` `=(6.626xx10^(-34)xx3xx10^8)/(253.7xx10^(-9))` `=7.835xx10^(-19)J` `=(7.835xx10^(-19))/(1.602xx10^(-9))`eV =4.89 eV So, from (1), 4.89=Work function + 0.24 work function = 4.65 eV |
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| 2. |
The threshold wavelength for the ejection of electrons from the metal X is 330 nm. The work function for the photoelectric emission for metal X is `(h = 66 xx 10^(-34) Js)`A. `1.2xx10^(-18) J`B. `6.0xx10^(-19) J`C. `1.2xx10^(-20) J`D. `6.0xx10^(-22) J` |
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Answer» Correct Answer - B Work function is given as =`hv^@ =(hc)/lambda^@` or Work function =`(6.62xx10^(-34)xx3xx10^8)/(330xx10^(-9))` `=6xx10^(-19) J` |
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| 3. |
A weight lifter, after weight lifting exercises. drinks 500 mL of 9% glucose (mol. Mass 180) solution. The number of glucose molecules consumed by him areA. `1.5xx10^23`B. `3.0xx10^23`C. `4.5xx10^23`D. `6.023xx10^23` |
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Answer» Correct Answer - A Mass of glucose consumed = 9 x 5 =45 g `therefore` No of glucose molecule consumed =`45/180xx6.02xx10^23=1.5xx10^23` |
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| 4. |
The molecule having zero dipole moment isA. `CIF_(3)`B. `CH_(4)`C. `PH_(3)`D. `CH_(2)Cl_(2)` |
| Answer» Correct Answer - (b) | |
| 5. |
Which of the following show correct structure of `lCl_(2)`?A. B. C. D. None of these |
| Answer» (b) To minimise lp-lp repulsion, they exit as shown in option (b). | |
| 6. |
The intermolecular interaction that is dependent on the inverse cube of distance between the molecules isA. Ion-ion interactionB. Ion-dipole interactionC. London forceD. Hydrogen bond |
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Answer» Correct Answer - B Ion -dipole interaction `prop 1/(r^(3))` |
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| 7. |
For two ionic solids, `CaO` and `KI`, which of the following statements is false?A. Lattice energy of CaO is much larger than that of KlB. Kl is soluble in benzeneC. Kl has lower melting pointD. CaO has higher melting point |
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Answer» Correct Answer - B KI is ionic compound, so it is not soluble in non-polar solvent (i.e. dipole moment (`mu`) for benzene =0) |
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| 8. |
What is the correct mode of hybridization of the central atom in the following compounds. `NO_(2)^(+),SF_(4),PF_(6)^(-)`A. `sp^(2),sp^(3),d^(2)sp^(3)`B. `sp^(3),sp^(3)d^(2),sp^(3)d^(2)`C. `sp,sp^(3)d,sp^(3)d^(2)`D. `sp,sp^(2),sp^(3)` |
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Answer» Correct Answer - C `{:("Atom/Ion",,"Hybridisation"),(NO_(2)^(+),,sp),(SF_(4),,sp^(3)d"with one lone pair of electron"),(PF_(6)^(-),,sp^(3)d^(2)):}` |
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| 9. |
The hybridization state of the central atom in `AlI_3` isA. `dsp^2`B. `sp^3`C. `sp^2`D. `sp` |
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Answer» Correct Answer - C The ground-state electron configuration of `Al` is `[Ne]3s^2 3p^1`. Therefore, `Al` has three valence electrons. All the valence electrons are used to form bonds with three univalent I atoms: `I-underset(I)underset(|)Al-I` There are three bonded atoms and no lone pairs on the `Al` atom. Thus, the steric number of `Al` in `All_3` is `3+0=3`. We conclude that `Al` must be `sp^2`-hybridized. We predict that the `All_3` molecule is planar and all the `I-Al-I` bond angles are `120^@`. |
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| 10. |
Hybridization of the central atom in `PF_3` isA. `sp`B. `dsp^2`C. `sp^2`D. `sp^3` |
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Answer» Correct Answer - D The ground-state electron configuration of central P atom is `[Ne]3s^2 3p^3`. Therefore, the P atom has five valence electrons. Three of the valence electrons are used to hold the three univalent F atoms and two nonbonding valence electrons form one lone pair. `F-underset(F)underset(|)overset(..)P-F` There are three bonded atoms and one lone pair on the central P atom. Thus, the steric number of `P` in `PF_3` is `3+1=4`. We conclude that P must be `sp^3`-hybridized. One of the `sp^3` hybrid orbitals is used to accomodate the lone pair on P while the other three `sp^3` hybrid orbitals from covalent `P-F` bonds with the `2p` orbitals of `F`. We predict the shape of the molecule to be pyramidal and the FPF bond angle should be somewhat less than `109.5^@`. |
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| 11. |
Molecular size of `ICI` and `Br_2` is nearly same but `b.pt.` of ` ICI` is about ` 40^@` higher than `BR_2` . This is due to :A. `I- Cl` bond is stronger than `Br -Br` bondB. ionisation enrgy of `I` gt ionisation enrgy of BrC. `ICl` is polar whereas `Br_2` is non-plarD. size of I is larger than `Br` |
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Answer» Correct Answer - C Polarity in a molecule give rise to an increase in forces of attraction among molecules and thus more becomes boiling point . |
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| 12. |
Molecular size of `ICI` and `Br_2` is nearly same but `b.pt.` of ` ICI` is about ` 40^@` higher than `BR_2` . This is due to :A. `ICl` is bigger than `Br_2`B. `I-Cl` is bond is stronger than `Br-Br` bondC. `ICl` is polar while `Br_2` is nonpolarD. `IE` of `BrgtIE` of I |
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Answer» Correct Answer - C Since `ICl` (heteronuclear diatomic molecule) is polar while `Br_2` (homonuclear diatomic) is nonpolar, the molecules of `ICl` are held together by dipole-dipole interactions while `Br_2` molecules are held together by weak dispersion forces. Note that during the process of boiling, we only overcome intermolecular attractions, we never break the covalent bonds between the atoms in a molecule. Thus option (2) cannot be correct. |
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| 13. |
Consider the b.pr. of `Br_2` and ICl. The b.pt. of `Br_2`A. is equal to the b.pt. of IC lB. is less than the b.pt. of IC lC. is more than the b.pt.of IC lD. none of these |
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Answer» Correct Answer - B IC l is a polar molecule due to electronegativity difference of I and Cl. On the other hand , `Br_2` is a non polar molecule, Due to greater |
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| 14. |
Which of the following are arranged in the decreasing order of dipole moment ?A. `CH_(3)Cl, CH_(3) Br, CH_(3) F`B. `CH_(3)Cl, CH_(3)F, CH_(3) Br`C. `CH_(3) Br, CH_(3) Cl, CH_(3) F`D. `CH_(3) Br, CH_(3) F, CH_(3) Cl` |
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Answer» Correct Answer - B The values of dipole moments of methyl halides , `CH_(3)F - 1.51 D , " "CH_(3) Cl - 1.56 D,` `CH_(3)Br - 1.4 D, " " CH_(3)I - 1.29 D` ` :. CH_(3) C l gt CH_(3) F gt CH_(3) Br gt CH_(3) I` |
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| 15. |
VSEPR THEORYA. the shape of the molecule depends upon the bonded electron pairsB. pair of electrons attract each other in valence shellsC. the pairs of electrons tend to occupy such positions that minimise repulsionsD. the pairs of electrons tend to occupy such positions that minimise distances from each other. |
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Answer» Correct Answer - C The pairs of electrons tend to occupy such positions that place them farthest from each other and minimise repulsions. |
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| 16. |
Bond angle between two hybrid orbitals is `106^@` Hybride charcter in orbital is :A. between ` 20 - 21 %`B. between ` 20 - 21 %`C. between ` 20 - 22 %`D. between ` 20 - 23 %` |
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Answer» Correct Answer - D Nearere to `25%` the angle is ` 109^@28` for `sp^3` -hybridsiation . |
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| 17. |
Give the decreasing `pH` of aqueous solution of the following compounds : a. `NaCl` , b. `MgCl_(2)` , c. `AlCl_(3)` , d. `PCl_(5)`A. `NaCl lt MgCl_(2) lt AlCl_(3)`B. `MgCl_(2) lt NaCl lt AlCl_(3)`C. `AlCl_(3) lt MgCl_(2) lt NaCl`D. `NaCl lt AlCl_(3) lt MgCl_(2)` |
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Answer» Correct Answer - A Cation size is decreasing in the order : ` Na^(+) gt Mg^(2+) gt Al^(3+)` `Al^(3+)` has maximum polarisation effect and `Na^(+) ` has minimum polarisation effect . The covalent nature is in the order : ` AlCl_(3) gt MgCl_(2) gt NaCl` |
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| 18. |
As the p - charcter increases the bond angle in in hydrid orbital formed by a and atomic orbitalsA. decreasesB. increasesC. doublesD. remains unchanged |
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Answer» Correct Answer - A As p-character increases the bond angle decreases. in sp-p-character `1/2` bond angle `-180^(@)` In `sp^(2)`-p-character `2/3` , bond angle `-120^(@)` In `sp^(3)`-p-character `3/4`, bond angle `109^(@)` |
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| 19. |
Which pair among the following is isostructural?A. `XeF_2, IF_2^(-)`B. `NH_3, BF_3`C. `CO_3^(2-)`D. `PCl_3, ICI_5` |
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Answer» Correct Answer - A Isostructural implies identical shape and geometry. Steric number of `Xe` in `XeF_2` is five (2 atoms bonded + lone pairs). Steric number of `I` in `IF_2^(-)` is also five (2 atoms bonded + 3 lone pairs). Therefore, both have trigonal bipyramidal geometry but linear shape. |
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| 20. |
Which of the following statements about LiC and NaCl is wrong?A. LICl has lower melting point than NaClB. LiCl dissolves more in organic solvents whereas NaCl does notC. LiCl would ionise in water more than NaClD. Fused LiCl would be less conducting than fused NaCl |
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Answer» Correct Answer - C LiCl will ionise less than NaCl, because of its larger covalent character. |
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| 21. |
In which pair both are not isostructural :-A. `BH_(4)^(-) & AlH_(4)^(-) `B. `NH_(4)^(+) & PH_(4)^(+)`C. `PCl_(6)^(-) & SiF_(6)^(-2)`D. `BCl_(4)^(-) & Icl_(4)^(-)` |
| Answer» Correct Answer - D | |
| 22. |
Among the following , the pair in which the two species are not isostructural isA. `IO_(3)^(-)` and `XeO_(3)`B. `AlH_(4)^(-)` and `PH_(4)^(+)`C. `AsF_(6)^(-)` and `SF_(6)`D. `SiF_(4)` and `SeF_(4)` |
| Answer» Correct Answer - 4 | |
| 23. |
`CO_(2)` is isostructural withA. `HgCl_(2)`B. `C_(2)H_(2)`C. `SnCl_(2)`D. `NO_(2)` |
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Answer» Correct Answer - a,b |
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| 24. |
Which of the following two are isostructural ?A. `XeF_2 , and IF_2^-`B. `NH_2, and BF_3`C. `CO_3^(2-) and SO_3^(2-)`D. `PCl_5 and IC l_5` |
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Answer» Correct Answer - A Compounds having some structure and same hybridisation are known as isostructural species. E.g. `XeF_2` and `IF_2^-` are `sp^3` d hybridised and both have linear shape. `F-I^(-)-F " " F-Xe-F` |
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| 25. |
Which of the following statements is wrong?A. KCl is soluble in waterB. HCl conducts electricity in its aqueous solutionC. Acetic acid is soluble in waterD. The bond formed between aluminum and fluorine is covalent. |
| Answer» Correct Answer - D | |
| 26. |
The tow carbon atoms in calcium carbide are held by which of following bonds ?A. Three sigma bondsB. Ioinic bondsC. Two pi and one sigma bondsD. Ionic and covalent bonds |
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Answer» Correct Answer - B `overlineC -=overlineC`bonding in ` CaC_2` |
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| 27. |
`NH_(4)^(+)` is isostructural withA. `PCl_(3)`B. `CH_(4)`C. `BF_(3)`D. `NO_(3)^(-)` |
| Answer» Correct Answer - B | |
| 28. |
All halides of sodium are ionic. Fluorides and chlorides of magnesium are ionic. But among halides of aluminum, only `AlF_(3)` is ionic. How do you account for this variation? |
| Answer» Polarizing power of the cation depends on its size and the charge present on it. The smaller the size and the higher the charge of the cation, the greater the polarizing power. Among `Na^(+)`, `Mg^(+2)` and `Al^(+3)`, `Al^(+3)` has least ionic size and the charge present on it is maximum. Hence, polarizing power of `Al^(+3)` is maximum. Among the halides `AlF_(3)` is ionic, but other halides of aluminium are covalent. Polarizing power of magnesium is less than aluminium. Hence, chloride and fluoride of magnesium are ionic. But `Na^(+)` has the least polarizing power. Hence, all the haldies of sodium are ionic. | |
| 29. |
Which of the following substances has the least ionic character ?A. `FeCl_2`B. `ZnCl_2`C. `CdCl_2`D. `MgCl_2` |
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Answer» Correct Answer - B `ZnCl_2` is a transition metal halide. Since zinc is less electropositive therefore it has less ionic character |
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| 30. |
Which of the following would have permanent dipple moment ?A. `BF_3`B. `SF_4`C. `SiF_4`D. `XeF_4` |
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Answer» Correct Answer - B `BF_3` is trigonal planar, `SiF_4` is tetrahedral, while `XeF_4` is square planar. All these molecules have zero dipole moment on account of symmetrical shapes. `SF_4` has seesaw shape which is not symmetrical and, hence, has a permanent dipole moment. |
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| 31. |
Which of the following would have permanent dipple moment ?A. `SF_4`B. `XeF_4`C. `SiF_4`D. `BF_3` |
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Answer» Correct Answer - A `SF_4` has `sp^3` d-hubridisation with one lone pair of electron on S-atiom leading to see -saw geomerty . |
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| 32. |
In water molecule, the bond angle of `104.5^(@)` around oxygen is accounted due toA. high electron affinity of oxygenB. very high repulsions between lone pair and bond pair of electrons.C. very high repulsion between lone pair and lone pair electronsD. small size of hydrogen |
| Answer» Correct Answer - C | |
| 33. |
Among the hydrogen halides ______ has maximum ionic character. |
| Answer» Correct Answer - HF | |
| 34. |
The shape of the molecule `SF_2Cl_2` isA. trigonal bipyramidalB. cubicC. octahedralD. tetrahedral |
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Answer» Correct Answer - A Sulphur is `sp^3d` hybridised. See text for calculating value of H |
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| 35. |
Which of the following is not linear ?A. `CO_(2)`B. `ClO_(2)`C. `I_3^(-)`D. None of these |
| Answer» Correct Answer - B | |
| 36. |
Number of electrons in the valence orbit of nitrogen in an ammonia molecule areA. 8B. 5C. 6D. 7 |
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Answer» Correct Answer - A The electronic configuraiton of nitrogen is `._(7)N=1s^(2),2s^(2),2p^(3)` It has 5 elements in valency shell, hence in ammonia molecule it complete its octet by sharing of three electron valence shell in ammonia molecule `Hxxunderset(H)underset(xx)underset(.)(.overset(..)(N))xxH` or `H-overset(..)underset(H)underset(|)(H)-H` |
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| 37. |
In the complex `[SbF_(5)]^(2-), sp^(3) d` hybridization is present. Geometry of the complex isA. squareB. Square pyramidalC. Square bipyramidalD. Tetrahedral |
| Answer» Correct Answer - B | |
| 38. |
Which of the following bonds is more polar when compared to other?A. O-HB. N-HC. C-HD. H-H |
| Answer» Correct Answer - A | |
| 39. |
For compounds , A : Tetracuanoethern B : Carbon dioxide C: Benzene D : 1 , 3-Butaidene . Ratio of `sigma` and ` pi` bonds is in order :A. A: TetracynoetheneB. B: Carbon dioxideC. C:BenzeneD. D , 1, 3 -Butadiene |
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Answer» Correct Answer - A `C_2(CN)_4` has `underset(("Ratio 1")) (9sigma, 9pi, CO_2) hasunderset(("Ratio 1"))(2 sigma , 2 pi)` Benzene has `underset("(Ratio 4)")(12 sigma, 3pi, 1, 3)`-butadiene has `underset("(Ratio 4.5)")(9 sigma, 2pi)` |
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| 40. |
The shape of `BeCl_(2)` is ______. |
| Answer» Correct Answer - linear | |
| 41. |
The shape of the ammonia molecule isA. tetrahedralB. Trigonal pyramidC. trigonal bipyramidalD. trigonal planar |
| Answer» Correct Answer - B | |
| 42. |
The shape of `H_(2)O` molecule is ______.A. linearB. tetrahedralC. v-shapedD. trigonal planar |
| Answer» Correct Answer - C | |
| 43. |
The number of `sigma` and `pi` bonds in `C_(2)H_(2)` is ______A. 0 and 4B. 2 and 2C. 3 and 2D. 4 and 2 |
| Answer» Correct Answer - C | |
| 44. |
The number of sigma and pi bonds in benzene areA. `6sigma` and `3pi` bondsB. `12sigma` and `3pi` bondsC. `9sigma` and `3pi` bondsD. `6sigma` and `6pi` bonds |
| Answer» Correct Answer - B | |
| 45. |
The shape of `CH_(3)^(+)` is …………. |
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Answer» Correct Answer - Triangular planar |
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| 46. |
…………… hybrid orbitals of nitrogen atom are involved in the formation of ammonium ion. |
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Answer» Correct Answer - `sp^(3)` |
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| 47. |
In which of the following molecules are all the bonds not equal ?A. `AlF_(3)`B. `NF_(3)`C. `ClF_(3)`D. `BF_(3)` |
| Answer» Correct Answer - C | |
| 48. |
Pair of molecules which forms strongest intermolecular hydrogen bonds is ……… `(SiH_(4)` and `SiF_(4)`, acetone and `CHCl_(3)`, formic acid and acetic acid) |
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Answer» Correct Answer - `HCOOH` and `CH_(3)COOH` |
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| 49. |
Which of the following molecules has both `p_(pi)-p_(pi) and p_(pi)-d_(pi)` bondsA. `XeO_(2)F_(2)`B. `SO_(2)Cl_(2)`C. `SO_(3)`D. `XeO_(3)` |
| Answer» Correct Answer - C | |
| 50. |
In which of the following molecules /ions , are all the bonds not equal ?A. `SF_4`B. `SiF_4`C. `XeF_4`D. `BF_4^-` |
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Answer» Correct Answer - A In ` SF_4` S `sp^3` d-hbridisation . It containse two axial and two equatorial bonds (see -saw structure) `. |
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