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.
| 29701. |
The increasing order of acid strength is ... |
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Answer» `CH_3COOH GT Cl_2CHCOOH gt "CCl"_3 CCOOH gt ClCH_2COOH` |
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| 29702. |
The ionisation energy of hydrogen atom (in the groundstate) is x kJ. The energy required for an electron to jump from 2^(nd) orbit to the 3^(rd)orbit will be |
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Answer» x/6 PUT `E_1=-K/n^2=-K/1^2=-K, THEREFORE K=x` `DeltaE=E_3-E_2=-K/3^2 - (-K/2^2)=K5/36=5/36x` |
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| 29703. |
The increasing order of acid strength of hydrogen halide in water is |
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Answer» HFgt HCL GT HBR gt HI |
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| 29704. |
The ionisation energy of hydrogen atom is 13.6 eV. What will be the ionisation energy of He^(+) and Li^(2+) ions? |
| Answer» SOLUTION :`54.4eV, 122.4eV` | |
| 29705. |
The increasing order of acid strength HClO_4 ,HClO_3 , HClO_2 HClO is |
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Answer» HCLO LT `HClO_2`lt `HClO_3` lt `HClO_4` |
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| 29706. |
The ionisation energy of He^(+) " is " 19.6 xx 10^(-18)J per atom. Calculate the energy of the first stationary state of Li^(2+) |
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Answer» Solution :The ionisation energy of `He^(+) " is " 19.6 xx 10^(-18)J` per ATOM `therefore` energy of the first ORBIT of `He^(+) (Z=2)= 19.6 xx 10^(-18)J` `therefore` enegy of the first orbit of `H^(+) (Z=1) = (19.6 xx 10^(-18))/(4)J` `therefore` energy of the first obit of `Li^(2+) (Z=3) = (19.6 xx 10^(-18))/(4) xx 9` `=4.41 xx 10^(-17)J` |
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| 29707. |
The ionisation energy of H atom is x kJ. The energy required for the electron to jump from n=2 to n=3 will be |
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Answer» 5X `=0-(-1311.8/1)=1311.8=x` Energy required `=-1311.8/(3^(2))-(-1311.8/(2^(2)))` `-x/9+x/4` or `(5x)/36`. |
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| 29708. |
The increasing order basicity among the following is |
| Answer» Answer :A | |
| 29709. |
The ionisation energy of dioxygen (O_2) is very close to that of Xenon. Also F and O have the highest electronegativity and consequently can oxidise Xe among rare gases. So Xe forms a large number of compounds with F and O. Xe and F_2 are mixed and reacted at different temperatures to give XeF_2, XeF_4 and XeF_6. Xe also forms an unstable gaseous XeO_4 and soild XeO_3 which Is a very powerful explosive at higher temperatures .Some of the rare gases form clathrates or cage compounds by being entrapped in the cages of cystals laiitice of water, phenol of quinols. Helium can form intersitital compound with transition metals. Bigger members of rare gases do not form such compounds because of their large size. XeF_6 cannot be prepard by the method : |
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Answer» `Xe+3F_2 underset"50 ATM"overset"475-532 K"to XeF_6` |
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| 29710. |
The ionisation energy of gaseous Na atoms is 495.8 KJ mol^(-1). The lowest possible frequency of light that can ionise a Na atom is |
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Answer» `1.24xx10^(15) s^(-1)` `=(495.8xx10^(3) "J/atom")/(6.02xx10^(23))xx(1)/(6.62xx10^(-34)JS)` `=1.24xx10^(14)s^(-1)` |
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| 29711. |
The increasing electron releasing tendencies of Cu , Ag , Fe and Zn are in the order : |
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Answer» Ag , CU , FE , ZN |
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| 29712. |
The ionisation energy of dioxygen (O_2) is very close to that of Xenon. Also F and O have the highest electronegativity and consequently can oxidise Xe among rare gases. So Xe forms a large number of compounds with F and O. Xe and F_2 are mixed and reacted at different temperatures to give XeF_2, XeF_4 and XeF_6. Xe also forms an unstable gaseous XeO_4 and soild XeO_3 which Is a very powerful explosive at higher temperatures .Some of the rare gases form clathrates or cage compounds by being entrapped in the cages of cystals laiitice of water, phenol of quinols. Helium can form intersitital compound with transition metals. Bigger members of rare gases do not form such compounds because of their large size. He and Ne do not from any clathrates because : |
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Answer» (A) He and NE are very large in size . |
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| 29713. |
The ionisationenergy of Ga is higher than that of Al because of _______ |
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Answer» more EFFECTIVE NUCLEAR charge of Ga |
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| 29714. |
The increasing basicity order of the following compounds is : (a) CH_3CH_2CH_2""(B)CH_3CH_2overset(CH_2CH_3)overset(|)(NH) H_(3)C-overset(CH_3)overset(|)N-CH_3""Ph-overset(CH_3)overset(|)(N)-H |
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Answer» (A) lt (B) lt (D) lt (C ) `CH_(3)CH_(2)NH_(2)""pK_(b)=3.29` `{:(CH_(3)CH_(2)-NH""pK_(b)=3.00),("|"),(""CH_(2)CH_(3)):}` `H_(3)C-UNDERSET(CH_(3))underset("|")"N "-CH_(3)""pK_(b)=4.22` |
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| 29715. |
The increase in the value of molar conductivity of acetic acid with dilution is due to |
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Answer» DECREASE in interionic FORCES |
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| 29716. |
The ionisation energy of dioxygen (O_2) is very close to that of Xenon. Also F and O have the highest electronegativity and consequently can oxidise Xe among rare gases. So Xe forms a large number of compounds with F and O. Xe and F_2 are mixed and reacted at different temperatures to give XeF_2, XeF_4 and XeF_6. Xe also forms an unstable gaseous XeO_4 and soild XeO_3 which Is a very powerful explosive at higher temperatures .Some of the rare gases form clathrates or cage compounds by being entrapped in the cages of cystals laiitice of water, phenol of quinols. Helium can form intersitital compound with transition metals. Bigger members of rare gases do not form such compounds because of their large size. Xenon fromthe larges number of compounds only with oxygen and fuorine because: (i) oxygen and fluorine have very high electronegativity. (ii) lonisation energy of Xe is the largest among rare gases.(iii) lonisationenergy of Xe is low compared to those of other rare gases. (iv) low disscoiation energy of fluorine molecule compared to those of CI_2 and Br_2 |
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Answer» (A) (I) (ll) (ILL) |
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| 29717. |
The ionisation energy of an element is |
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Answer» The same as the electron AFFINITY of the element |
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| 29718. |
The ionisation constant of overset(oplus)NH_(4)ion in water5.6xx10^(-10)" at "25^(@)CThe rate constant for the reaction of overset(oplus)NH_(4) and oversetThetaOHion to formNH_(3) and H_(2)O " at " 25^(@)C" is " 3.4xx10^(10)"L.mol"^(-1).s^(-1) Calculate the rate constant for proton transfer from water toNH_(3) |
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Answer» Solution :Given `NH_(4)^(+)+H_(2)OhArrNH_(3)+H_(3)O^(+)` `K_(a) = ([NH_(3)][H_(3)O^(+)])/([NH_(4)^(+)][H_(2)O]) (K_(a)= 5.6xx10^(-10))""...[1]` `NH_(4)^(+)+BAR(O)Hunderset(k_(b))OVERSET(k_(f))hArrNH_(3)+H_(2)O` `""(k_(f)=3.4xx10^(10)"L.mol"^(-1).s^(-1))""...[2]` `K_(eq)=(k_(f))/(k_(b))=([NH_(3)][H_(2)O])/([NH_(4)^(+)][OH^(-)])` `=([NH_(3)][H_(3)O^(+)])/([NH_(4)^(+)][H_(2)O])xx([H_(2)O]^(2))/([H_(3)O^(+)][OH^(-)])=(K_(a))/(K_(W))` `thereforek_(b)=(K_(w))/(K_(a))xxk_(f)=(1.0xx10^(-14))/(5.6xx10^(-10))xx3.4xx10^(10)=6.07xx10^(5)` |
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| 29719. |
The increase in solubility of iodine in an aqueous solution of potassium iodide is due to the formation of ................... . |
| Answer» SOLUTION :`KI_(3)` | |
| 29720. |
The ionisation constant of phenol is higher than that of ethanol because |
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Answer» phenoxide ion is BULKIER than ethoxide. |
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| 29721. |
The ionisation constant of NH_4^+ in water is 5.6xx10^(-10) at 25^@C the rate constant for the reaction of NH_4^+ and OH^- to form NH_3 and H_2O at 25^@C IS 3.4xx10^10L mol/sec Find the rate constant for proton transfer from water to NH_3? |
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Answer» `6.07xx10^5 s^(-1)` |
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| 29722. |
The ionisation constant of HF, HCOOH ,HCN at 298 K are 6.8 times 10^-4.1.8 times 10^-4 and 4.8 times 10^-9. Respectively. Calculate the ionisation constant of the corresponding conjugate base. |
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Answer» Solution :(i) HF, CONJUGATE base F `K_b=K_w//K_a=(1 times 10^-4)/(6.8 times 10^-4)=1.47 times 10^-11= 1.5times 10^-11` (ii) for `HCOO^-` `K_b=(1 times 10^-14)/(1.8 times 10^-4)=5.6 times 10^-11` (iii) for `CN^-` `K_b=(1 times 10^-14)/(4.8 times 10^-4)=2.8 times 10^-6` |
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| 29723. |
The ionisation constant of ammonium hydroxide is 1.77xx10^(-5) at 298 K. Hydrolysis constant of ammonium chloride is : |
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Answer» `6.5xx10^(-12)` |
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| 29724. |
The ionisation constant of 0.2 M formic acid is 1.8xx10^(-4). Calculate its percentage ionisation. |
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Answer» SOLUTION :FORMIC acid is a weak acid. Let is be represented as HA. `underset(C(I-alpha))(HA) hArr underset(C alpha)( H^(+))+underset(C alpha)(A^-)` ACCORDING to Ostwald's dilution law, `K_a=C alpha^2. ` `therefore alpha=sqrt(K_a)/(C )` `K_a=1.8xx10^(-4), C=0.2 M=2xx10^(-1) M` ` therefore alpha =sqrt((1.8xx10^(-4))/(2xx10^(-1)))=sqrt(9xx10^(-4)3xx10^(-2))` Percentage of IONISATION `= 100 alpha ` `=10^2 xx3xx10^(-2)=3` |
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| 29725. |
The increase in rate constant of a reaction is more when the temperature increases from |
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Answer» 290K - 300K |
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| 29726. |
The ionisation constant for NH_(4)^(+) in water is 5.0xx10^(-10)" at " 25^(@)C. The rate constant for the reaction of NH_(4)^(+) and OH^(-) to form NH_(3) and H_(2)O" at " 25^(@)C is 3.0xx10^(10)" Lmol"^(-1)s^(-1). The rate constant for proton transfer from water to NH_(3) is x xx 10^(5). The value of 'x' is |
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Answer» |
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| 29727. |
The ionisation constant for acetic acid is 1.8xx10^(-5). At what concentration will it be dissociated to 2% ? |
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Answer» 1 M `=4.5xx10^(-2)=0.045 M` |
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| 29728. |
The ionic radius of._(57)La^(3+) is 1.06Å. Which one of the following given values will be closest to the ionic radius of ._21Lu^(3+)? |
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Answer» 1.06Å |
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| 29729. |
Theionic radius ofCl^(-)ion is1.81 Å . The inter-ionic distances of NaCl andNaF are2.79 Årespectively. The ionic radiusof F^(-)ionwill be |
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Answer» `0.98 Å` `2.79=r_(Na)+1.81` or`r_(Na)+=2.79-1.81 Å =0.98 Å` `d_(NAF)=r_(Na).^(+)+r_(F).^(-)`, i.e.,`2.31=0.98+r_(F).-`or `r_(F).- =2.31-0.98=1.33 Å` |
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| 29730. |
The increase in rate constant of a chemical reaction with increasing temperature is(are) due to the fact(s) that |
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Answer» the NUMBER of collisons AMONG the reactant MOLECULES increases with increasing TEMPERATURE. |
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| 29731. |
The ionic radii of Rb^+ andI^- are 1.46overset@A and 2.16overset@A. The most probable type of structure exhibited by it is : |
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Answer» CSCL TYPE |
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| 29732. |
The increase in boiling point of a solution containing 0.6 g urea in 200 g water is 0.50^(@)C, find the molal elevation constant. |
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Answer» `1.0"K kg mol"^(-1)` |
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| 29733. |
The increase in boiling points of noble gases from He to Xe is due to the |
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Answer» decreases in ionization energy |
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| 29734. |
The incorrect statemetns amgong the following is |
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Answer» The entropy of the universe REMAINS CONSTANT |
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| 29735. |
The incorrect structure of glycine at given pH are : |
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Answer» `H_3overset(o+)NCH_2-UNDERSET(O)underset(||)C-OH" at " PH = 2.0` |
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| 29736. |
The Incorrect statements(s) among the following is/are :- |
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Answer» The FIRST ionisation energy of calcium is more than first ionisation energy of Gallium |
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| 29737. |
The incorrect statement(s) regarding oxides of group-16 elements is/are |
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Answer» Reducing property of dioxide DECREASES from `SO_(2) " to " TeO_(2)` |
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| 29738. |
The incorrect statement(s) about Cr^(2+) and Mn^(3+)is (are) [Atomic numbers of Cr = 24 and Mn = 25] |
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Answer» `CR^(2+)` is a reducing agent |
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| 29739. |
The incorrect statements among the following is/are (I) NCl_5 does not exist while PCl_5 does (II) Lead prefers to form tetravalent compounds in the carbonate ion (III) The three C-O bonds are not equal in the carbonate ion (IV) Both O_2^(+) and NO one paramagnetic |
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Answer» I,III, and IV |
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| 29740. |
The incorrect statement(s) among the following is/are |
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Answer» the first ionization potential of AL is less than the first ionization potential of Mg |
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| 29741. |
The incorrect statement(s) among the following is/are? |
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Answer» In aqueous solution `NA` has stronger reducing character than `LI`. (ii) `Li_(2)CO_(3)` is thermally less stable than `Na_(2)CO_(3)`. |
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| 29742. |
The incorrect statement (s) regarding 2M MhCl_(2) aqueous solution is/are (d_("solution") = 1.09 gm//ml) |
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Answer» Molality of `CL^(-)` is 4.44 m |
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| 29743. |
The incorrect statement with respect to saccharin is |
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Answer» Artificial sweetening agent |
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| 29744. |
The incorrect statement with respect to valence bond theory |
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Answer» The electrons in the metal orbitals may undergo regrouping even against Hund's rule. |
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| 29745. |
The incorrect statement (s) regarding overline(*)(C)X_(3) |
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Answer» If electronegativity of SURROUNDING element X is LESS than 2.5, then central carbon atom used almost 33% s-character in their HYBRID bonding orbital |
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| 29746. |
The incorrect statement regarding transition elements is |
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Answer» They have low tensile STRENGTH |
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| 29747. |
The incorrect statement regarding to Noble gases is |
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Answer» Their electronegetive values are zero |
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| 29748. |
The incorrect statement regarding structure of ozone is ________ |
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Answer» Bond angle is less than `120^(@)` |
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| 29749. |
The incorrect statement regarding O(SiH_(3))_(2) and OCl_(2) molecule is/are |
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Answer» The strength of back BONDING is more in`O(SiH_(3))_(2)` molecule than `Ocl_(2)` molecule hybridisation of O-atom : `sp^(2)` due to more extent of `(2p_(pi)-3d_(pi))` back bonding. Hybridisation of O-atom remains `sp^(3)`, becouse of LESS effective `(2p_(pi)-3d_(pi))` back bonding due to d-orbital resonance
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| 29750. |
The Incorrect statement regarding Nelson cell process |
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Answer» `H_(2)andNaOH` are the by products in this process |
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