52671 + Interview Questions in Chemistry in Class 11

1.	Bond angle in alkenes is equal to
Answer» `120^@ ` `109^@ 28'` `180^@` `60^@` ANSWER :A

Discussion

2.	Bond angle in alkene (C_2H_4) in equal to
Answer» `120^(@) ` `109^(@) 28^(@)` `180^(@) ` `60^@` Solution :`12^(@) ` (`SP^(2)` hybridisation )

Discussion

3.	Bond angle (H-O-H) in H_(2)O is
Answer» `90^(@)` `104^(@) 30` `107^(@) 18` `109^(@) 28` Answer :B

Discussion

4.	Bomb calorimeteris used to determine the value of "….........................".
Answer» Solution :`DELTAU ` ( i.e.,internal energy CHANGE viz. heat of reaction at CONSTANT VOLUME)

Discussion

5.	Boltzmann constant represents the gas constant per
Answer» MOLE AVOGADRO number of MOLECULES any number of molecules molecule SOLUTION :`K = R/(N_0)`

Discussion

6.	Boiling points of methanol, water and dimethyl ether are respectively 65^@ C, 100^@ C and 34.5^@C. Which of the following best explains the wide variations in boiling points?
Answer» Density of water is 1g`ml^(-1)`, methanol is 0.79g`ml^(-1)` and dimethyl ether is 0.71g`ml^(-2)` Molecular weight increases from water (18) to methanol (32) to dimethyl ether (46) EXTENT of HYDROGEN bonding decreases from water to methanol, while it is absent in ether The NUMBER of H ATOMS per molecule increases from water to methanol to ether. Answer :C

Discussion

7.	Boiling point of water is very high.
Answer» Solution :Due to the presence of INTERMOLECULAR HYDROGEN bonding in water.

Discussion

8.	Boiling point of water in Fahrenheit ?
Answer» SOLUTION :`F = 9/5(""^(@)C) + 32` (b.p, of WATER `100 ""^(@)C`) `= 9/5 xx 100+32=212F`

Discussion

9.	Boiling point of heavy water is
Answer» `100^@C` `99^@C` `101.42^@C` `110^@C` ANSWER :C

Discussion

10.	Boiling point of covalent compound depends on intennolecular force. Intermolecular forces are the force of attraction and repulsion between interacting particles (atoms and molecules). This term does not include the electrostatic forces that exist between the two oppositely charged ions and the forces that hold atoms of a molecule together i.e., covalent bonds Which of the following hydrogen bonds is the strongest?
Answer» O-H-----N F- H-----F O-H--0 0-H--F Answer :B

Discussion

11.	Boiling point of a liquid depends upon
Answer» Temperature VOLUME PRESSURE Moisture ANSWER :C

Discussion

12.	Boiling point is highest for
Answer» HF `H_2 O` `NH_3` `CH_4` ANSWER :B

Discussion

13.	Bohr.s theory is not applicable to
Answer» H `He^(+)` `Be^(3+)` `H^(+)` ANSWER :D

Discussion

14.	Bohr.s theory is applicable to
Answer» `LI^(+2)` `Li^(+)` `He^(+)` Both 1 and 3 Answer :D

Discussion

15.	Bohr.s theory explains that when Hydrogen-like particles are excited, their electrons are shifted higher energy orbits. As such a state of atom is not stable, electrons return to lower energy orbits releasing quantum of energy. Thus different spectral lines are formed. The wave number of spectral line is given by bar(v) = (2pi^(2)me^(4)z^(2))/(c h^(3))[(1)/(n_(1)^(2)-(1)/(n_(2)^(2)))] For a hydrogen -like particle, ionization energy is 122.4 eV. Then what is the wave number of series limit spectral line of the particle of paschen seres (R = rydberg.s constant)
Answer» `(R)/(9)` `(R)/(3)` R 4R Answer :C

Discussion

16.	Bohr.s theory explains that when Hydrogen-like particles are excited, their electrons are shifted higher energy orbits. As such a state of atom is not stable, electrons return to lower energy orbits releasing quantum of energy. Thus different spectral lines are formed. The wave number of spectral line is given by bar(v) = (2pi^(2)me^(4)z^(2))/(c h^(3))[(1)/(n_(1)^(2)-(1)/(n_(2)^(2)))] The angular momentum of an electron in a Bohr.s orbit of H-atom is 4.2178 xx 10^(-34) kg m^(2) sec^(-1). What is the wave number of the spectral line emitted when electron falls from this level to the next lower level
Answer» `(7R)/(144)` `5.5 XX 10^(-4) CM^(-1)` `(8)/(9)R` `1.1 xx 10^(-5)cm^(-1)` Answer :A

Discussion

17.	Bohr.s theory explains that when Hydrogen-like particles are excited, their electrons are shifted higher energy orbits. As such a state of atom is not stable, electrons return to lower energy orbits releasing quantum of energy. Thus different spectral lines are formed. The wave number of spectral line is given by bar(v) = (2pi^(2)me^(4)z^(2))/(c h^(3))[(1)/(n_(1)^(2)-(1)/(n_(2)^(2)))] When electrons of excited H-atoms make transition from fifth excited state to second orbit, then maximum number of different types of photos observed is
Answer» 3 6 10 4 Answer :C

Discussion

18.	Bohr's postulate that mv r = (nh)/(2pi) is proved mathematically by
Answer» Pauli.s exclusion principle de BROGLIE WAVE nature of the electron Heisenberg uncertainity principle Sommerfield theory Answer :C

Discussion

19.	Bohr's equation for energy of an electron in a hydrogen atom is given as _________.
Answer» `E = (-1312)/(n^2) KJ MOL^(-1)` `E = (-1312)/(n^2h^2) KJ mol^(-1)` `E = hv` `E = (4pi^2 m e^4)/(n^2h^2) KJ mol^(-1)` ANSWER :A

Discussion

20.	Bohr radius of 1^(st) orbital of hyddrogen atom is 0529A.Assuming that the position of an electron in this orbit is determined with the accuracy of 0.5% of the radius,calculate the uncertainty in the velocity of the electron in hydrogen atom.
Answer» Solution :UNCERTAINTY in POSITION`=/_\x` `=(0.5%)/(100%)xx05.29A` `=(0.5)/(100)xx10^(-10)xx0.529m` `/_\x=2.645xx10^(13)m` From Heisenberg.s uncertainty principle, `/_\x./_\.+h/(4pi)` `/_\x.m./_\V.+h/(4pi)` `/_\vgt=h/(/_\x.m.4pi)` `/_\v=(6.626xx10^(-34)Khm^(2)s^(-1))/(2.645xx10^(13)mxx9.11xx10^(-31)kGxx4xx3.14)` `/_\v=2.189xx10^(8)m`

Discussion

21.	Bohr proposed his atomic model based on Planck.s quantum theory and derived following relations for one electron system in C.G.S. units : For H -atom : r_(n) = n^(2) xx r_(1), E_(n) = E_(1) xx Z^(2), u_(n) = (u_(1))/(n), u_(1) = 2.19 xx 10^(8) cm//sec., E_(1) = -13.6eV For 1 electron system, other than H r_(n) = (n^(2) xx r_(1H))/(Z), E_(N) = (E_(1H) xx Z^(2))/(n^(2)), u_(n) = (u_(1H) xx Z)/(n). Later on de Broglie proposed the dual nature of electron and put forward his wave concept. The wave length of electron in an orbit was given lambda = h/mu The potential energy of electron in3^(rd) Bohr orbit of H-atom is :
Answer» `-242 xx 10^(-12)` erg `-4.84 xx 10^(-12)` erg `+4.84 xx 10^(-12)` erg `+2.42 xx 10^(-12)` erg Answer :B

Discussion

22.	Bohr’s atomic model could explain the spectrum o f ............
Answer» Atoms or IONS which have TWO electrons. Only dihydrogen MOLECULE. `He^(-)` atom only. Atoms or ions which contain only ONE electron Answer :D

Discussion

23.	Bohr.satomicmodel.
Answer» Solution :Nells Bohr (1913) was the firstto explainquqntitatively thegeneralfeaturesof hydrogenatomstructure andtisspectrum. Pitulatesof model: (i) Theelectron is the hydrogenatom can movearoundthenucleusin acircularpathcalledorbitsstationarystatesor allowedenergystates. Theseorbitsare arrangestconcentrically aroundthe nucleus. (ii) The energyof anelectronin the orbit DOESNOT changewith timeHowever the electron willmovefroma lowerstationarystateto ahigherstationarystatewhenrequiredor energyis emitted whenelectronmovesdoesnottakeplace in acontinuouschange (iii) The frequency of radiationabsorbedoremitted whentransitionoccursbetweentwostationarystatesthatdifferin energyby Where`E_(1)`and `E_(2)`are the energies of lowerand higherallowedenergystatesrespectivelythisexpressionis commonlyknown asbohrfrequencyrule Thusanelectroncan MOVE only in thoseorbitsfor whichitsangularmomentumisintegralmultiple of `((h)/( 2pi))` that iswhyonlycertain fixedorbitsare ALLOWED.

Discussion

24.	Bohr proposed his atomic model based on Planck.s quantum theory and derived following relations for one electron system in C.G.S. units : For H -atom : r_(n) = n^(2) xx r_(1), E_(n) = E_(1) xx Z^(2), u_(n) = (u_(1))/(n), u_(1) = 2.19 xx 10^(8) cm//sec., E_(1) = -13.6eV For 1 electron system, other than H r_(n) = (n^(2) xx r_(1H))/(Z), E_(N) = (E_(1H) xx Z^(2))/(n^(2)), u_(n) = (u_(1H) xx Z)/(n). Later on de Broglie proposed the dual nature of electron and put forward his wave concept. The wave length of electron in an orbit was given lambda = h/mu The circumference (in m) of 3^(rd) Bohr orbit in H-atom is :
Answer» `3.0 XX 10^(-7)` `3.0 xx 10^(-8)` `3.0 xx 10^(-6)` `3.0 xx 10^(-9)` ANSWER :D

Discussion

25.	Bohr model of atom is contradicted by
Answer» Pauli EXCLUSION PRINCIPLE PLANCK QUANTUM theory HEISENBERG uncertainty principle All of these Answer :C

Discussion

26.	Bohr’s theory based on the Planck’s quantum theory.
Answer» ANSWER :T

Discussion

27.	Bohr’s theory cannot explain the spectra of multi-electron atoms.
Answer» ANSWER :T

Discussion

28.	Bohr model of hydrogen atom contradicts dual behaviour of matter and Heisenberg’s uncertainty principle. Justiy.
Answer» SOLUTION :According to de Broglie concept, a moving electron has both particle and wave character. But Bohr considered electron only as particles. HEISENBERG’s uncertainty principles RULES out the existence of definite paths for electrons. But in Bohr’s model, electron in an atom is ASSUMED to be REVOLVING around the nucleus through definite paths called orbits.

Discussion

29.	BOH_((aq)) + H_((aq))^(+) rarr B_((aq))^(+) + H_2O, DeltaH = -48 KJ.Heat of ionisation of the weak base is
Answer» `9.3 KJ` `- 9.3 KJ` `48 KJ` `- 5 KJ` ANSWER :A

Discussion

30.	Bohr’s atomic theory is not able to explain the atomic spectra of atoms containing ________electron.
Answer» SOLUTION :more than 1

Discussion

31.	Bohr’s theory is based on ________ of radiation.
Answer» SOLUTION :Planck.s THEORY

Discussion

32.	B(OH)_(3)+NaOH rarr Na[B(OH)_(4)]+H_(2)O How can this reaction is made to proceeds in forward direction ?
Answer» ADDITION of cis-1,2-diol Addition of BORAX Addition of trans-1,2-diol Addition of `Na_(2)HPO_(4)` Answer :A

Discussion

33.	B(OH)_(3)+NaOH hArr NaBO_(2)+Na[B(OH)_(4)]+H_(2)OHow can this reaction is made to proceed in forward direction ?
Answer» addition of cis - 1, 2 DIOL addition of borax addition of trans-1, 2 diol addition of `Na_(2)HPO_(4) Na_(2) HPO_(4)` SOLUTION :

Discussion

34.	B(OH)_3 is ……………… in nature.
Answer» SOLUTION :ACIDIC

Discussion

35.	Body centred cubic lattice has co-ordination number of
Answer» 8 12 6 4 Answer :A

Discussion

36.	Body centred cubic lattic has a coordination number
Answer» 8 12 6 4 Solution :BCC has a COORDINATION NUMBER of 8.

Discussion

37.	BOD_5 is
Answer» waste DECOMPOSED in 5 days oxygen USED in 5 days microorganisms killed in 5 days dissolved oxygen LEFT after 5 days Answer :B

Discussion

38.	BOD values less than 5 ppm indicates a water sample to be
Answer» POOR in DISSOLVED oxygen rich in dissolved oxygen Highly polluted Not SUITABLE for AQUATIC life Answer :B

Discussion

39.	BOD stands for____________.
Answer» ANSWER :A::B::C::D

Discussion

40.	B.O.D is connected with
Answer» Organic MATTER MICROBES Microbes and organice matter NONE of the above Solution :BOD is CONNECTED with microbes and organic matter present in the WATER

Discussion

41.	BOD is a measure of ......
Answer» ORGANIC POLLUTANTS in WATER Inorganic pollutants in water Particulate MATTER in water All of the above Solution :Organic pollutants in water

Discussion

42.	BOD is a measure of .................
Answer» SOLUTION :ORGANIC POLLUTANT in WATER

Discussion

43.	BOD is a measure of :
Answer» Organic POLLUTANT in water Oxides of SPN in air INORGANIC pollutant in water Particle matter in water. Answer :A

Discussion

44.	BOD is
Answer» Biological oxygen DEFICIT BIOSPHERE oxygen demand Biological oxygen demand NONE of the above SOLUTION :B.O.D is biological oxygen demand

Discussion

45.	Blue compound Q is:
Answer» `Co(BO_(2))_(2)` `NaCoPO_(4)` `CoO.AI_(2)O_(3)` `CoO.MgO` Solution : `Q RARR NaCoPO_(4)`, `R rarr Mg(NH_(4))PO_(4)`

Discussion

46.	Blue colour of C is due to the formation of :
Answer» `Mn^(2+)` `CrO_(5)` `I_(2)` `H_(2)TiO_(4)` ANSWER :C

Discussion

47.	Blue color of concentrated ammoniated solution of alkali metals get converted into ......... color.
Answer» BLACK - BLUE Black - green Violet Colorless Answer :A

Discussion

48.	Blood may be purified by
Answer» Dialysis Electroosmosis Coagulation Filtration Answer :A

Discussion

49.	Blood is a buffer of H_(2)CO_(3) and[HCO_(3)^(-)]with pH = 7.40. Given K_(1)of H_(2)CO_(3) = 4.5xx10^(-7). What will be the ratio of [HCO_(3)^(-)] to [H_(2)CO_(3)] in the blood ?
Answer» SOLUTION :`H_(2)CO_(3)hArr H^(+)+HCO_(3)^(-), K_(1)=([H^(+)][HCO_(3)^(-)])/([H_(2)CO_(3)]) or ([HCO_(3)^(-)])/([H_(2)CO_(3)])=(K_(1))/([H^(+)])` `PH = 7.40` means - log `[H^(+)] = 7.4` or log `[H^(+)] = -7.4= bar(8).6or [H^(+)]=3.981 xx 10^(-8)` `([HCO_(3)^(-1)])/([H_(2)CO_(3)])=(4.5xx10^(-7))/(3.981xx10^(-8))=11.3`.

Discussion

50.	Blister copper is
Answer» Impure Cu Cu alloy PURE Cu copper having 1% impurity Solution :Theoretically AL can reduced MgO to Mg above 1623 K .SINCE Mg is costelier than Al and a higher TEMPERATURE (gt 1623 K) is difficult to maintain. THEREFORE, Mg is usually obtained by reduction of MgO by Al .

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Bond angle in alkenes is equal to

Bond angle in alkene (C_2H_4) in equal to

Bond angle (H-O-H) in H_(2)O is

Bomb calorimeteris used to determine the value of "….........................".

Boltzmann constant represents the gas constant per

Boiling points of methanol, water and dimethyl ether are respectively 65^@ C, 100^@ C and 34.5^@C. Which of the following best explains the wide variations in boiling points?

Boiling point of water is very high.

Boiling point of water in Fahrenheit ?

Boiling point of heavy water is

Boiling point of a liquid depends upon

Boiling point is highest for

Bohr.s theory is not applicable to

Bohr.s theory is applicable to

Bohr's postulate that mv r = (nh)/(2pi) is proved mathematically by

Bohr's equation for energy of an electron in a hydrogen atom is given as _________.

Bohr radius of 1^(st) orbital of hyddrogen atom is 0529A.Assuming that the position of an electron in this orbit is determined with the accuracy of 0.5% of the radius,calculate the uncertainty in the velocity of the electron in hydrogen atom.

Bohr’s atomic model could explain the spectrum o f ............

Bohr.satomicmodel.

Bohr model of atom is contradicted by

Bohr’s theory based on the Planck’s quantum theory.

Bohr’s theory cannot explain the spectra of multi-electron atoms.

Bohr model of hydrogen atom contradicts dual behaviour of matter and Heisenberg’s uncertainty principle. Justiy.

BOH_((aq)) + H_((aq))^(+) rarr B_((aq))^(+) + H_2O, DeltaH = -48 KJ.Heat of ionisation of the weak base is

Bohr’s atomic theory is not able to explain the atomic spectra of atoms containing ________electron.

Bohr’s theory is based on ________ of radiation.

B(OH)_(3)+NaOH rarr Na[B(OH)_(4)]+H_(2)O How can this reaction is made to proceeds in forward direction ?

B(OH)_(3)+NaOH hArr NaBO_(2)+Na[B(OH)_(4)]+H_(2)OHow can this reaction is made to proceed in forward direction ?

B(OH)_3 is ……………… in nature.

Body centred cubic lattice has co-ordination number of

Body centred cubic lattic has a coordination number

BOD_5 is

BOD values less than 5 ppm indicates a water sample to be

BOD stands for____________.

B.O.D is connected with

BOD is a measure of ......

BOD is a measure of .................

BOD is a measure of :

BOD is

Blue compound Q is:

Blue colour of C is due to the formation of :

Blue color of concentrated ammoniated solution of alkali metals get converted into ......... color.

Blood may be purified by

Blood is a buffer of H_(2)CO_(3) and[HCO_(3)^(-)]with pH = 7.40. Given K_(1)of H_(2)CO_(3) = 4.5xx10^(-7). What will be the ratio of [HCO_(3)^(-)] to [H_(2)CO_(3)] in the blood ?

Blister copper is