94420 + Interview Questions in Chemistry in Class 12

1.	The electronic configuration of transition element "X", is +3, oxidation state is [Ar]3d^(5). What is its atomic number?
Answer» 25 26 27 24 Solution :`X^(3)` : [Ar] `3d^(5) = 23` ELECTRONS. Since `X^(3+)` Ionis formed by the LOSS of 3 electrons . X will have 26 electrons. Therefore, ATOMIC number of X is 26.

Discussion

2.	Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d^5.What is its atomic number?25,26,27,24.
Answer» 25 26 27 24 Answer :B

Discussion

3.	Electronic configuration of a transition element X in + 3 oxidation state is [Ar]3d^5 What is its atomic number?
Answer» 25 26 27 24 Solution :Electronic CONFIGURATION of `X^(3+)` [AR] `3D^(5)` = 23 electrons. Since `X^(3+)` is formed by the loss of three electrons, number of electrons in X is = 23 + 3 = 26. Therefore, the ATOMIC number of the element is 26

Discussion

4.	Electronic configuration of a transition element X in (+3) oxidation state is [Ar]3d^(5). What is its atomic number?
Answer» 25 26 27 24 Solution :`X^(+3): [Ar] 3d^(5)` `:. X = [Ar] 3d^(6) 4S^(2) rArr Z= 26`

Discussion

5.	Electronic configuration of a transition element X in +3 oxidation state is [Ar] 3d^(5) . What is its atomic number ?
Answer» 25 26 27 24 Solution :`X^(3+)= [Ar]^(18) 3D^(5) = 23 ` electrons . As `X^(3+)` is FORMED by loss of 3 electrons from X,X will have 26 electrons. `:. `At. No. of X = 26

Discussion

6.	Electronic confriguration of a transition element X in +3 oxidation states is [Ar]3d^(5). What is its atomic number?
Answer» 25 26 27 24 Answer :B

Discussion

7.	Electronic arrangement of pollonium is..........
Answer» `[Kr]4f^(14) 5d^(10)6s^(2)6p^(3)` `[Xe]4f^(14)5d^(10)6s^(1)6p^(3)` `[Rn]5f^(14)6D^(10)7s^(2)7p^(4)` `[Xe]4f^(14)5d^(10) 6s^(2) 6p^(4)` ANSWER :D

Discussion

8.	Electrical conductance of metals decreases with increase in temperature.
Answer» ANSWER :1

Discussion

9.	Electronegtivity of beryllium is approximately equal to that of :
Answer» Aluminium Boron Magnesium Sodium Answer :A

Discussion

10.	Electronic arrangement of Lv is...........
Answer» `[XE]4f^(14)5d^(10)6S^(2)6P^(4)` `[Rn]4f^(14)5d^(10)6s^(2)6p^(6)` `[Rn]4f^(14)5d^(10)6s^(2)6p^(6)` `[Rn]5F^(14)6d^(10)7s^(2)7p^(4)` Answer :D

Discussion

11.	Oxyen is more eletrongative than sulphur, yet H_(2)S is acidic while H_(2)O in neutral.this is because:
Answer» water is highly ASSOCIATED compound molecular mass of `H_2S` is more than `H_2O` `H_2S` is as while `H_2O` is a liquid H - S bond is WEAKER than H - O bond Solution :`H_2S` dissociates more to give `H^+` ION as H-S bond is weaker than H-O bond

Discussion

12.	Electronegativity of beryllium is approximately equal to that of
Answer» aluminium Boron Magnesium SODIUM SOLUTION :`{:("ELEMENT-","Be","AL"),("Electronegativity-" ,1.5,1.5):}`

Discussion

13.	Electronegativity of an inert gas is :
Answer» HIGH Low Negative Zero Answer :D

Discussion

14.	Electronegativity is defined as attracting power of sharing pair of electron between covalently bonded atoms. Electronegativity is defined on different scales, F has height electronegativity between all elements. Which of the following nitrogen oxide acidic in nature but give two different acids on hydrolysis ?
Answer» NO `N_(2)O_(3)` `N_(2)O_(5)` `NO_(2)` ANSWER :D

Discussion

15.	Electron ________groups in phenol decrease its acidic strength.
Answer» SOLUTION :RELEASING

Discussion

16.	Electron given enthalpies of halogens are largely negative. Give reasons.
Answer» Solution :When an isolated gaseous atom accepts ONE electron, energy is released and HENCE its electrongain enthalpy is negative. Since halogens have one electron less than the nearest inert gas configuration, therefore, they have a strong tendency to ACCEPT an additional electron and hence have negative electron gain ENTHALPIES. Further since electron gain enthalpy BECOMES less and less negative (but still remains negative) as we move down the group form F to I, therefore, electron gain enthalpies of halogens are largely negative.

Discussion

17.	Electron gain enthalpy of fluorine is less than that of chlorine. Why?
Answer» SOLUTION :Fluorine ATOM is small in size and suffers with interelectronic repulsions between seven valence electrons . The added ELECTRON EXPERIENCES much repulsion on smaller F. Hence its electron gain enthalpy is LESS.

Discussion

18.	Electron gain enthalpies of noble gases are negative.
Answer» SOLUTION : ELECTRON GAIN enthalpics of NOBLE GASES are positiove.

Discussion

19.	Electron gain energy is maximum in case of
Answer» O S Te Se Answer :B

Discussion

20.	Electron donating groups are,
Answer» o-direction p-directing m-directing o and p-directing ANSWER :D

Discussion

21.	Electron deficient species are known as electrophiles. All positviely changed species are not electronphilic. Covalent compound having complete octer but if central atom has unfilled d-orbital also act as electrophiles. All electrophiles are not always Lewis acid Which of the following electrophile is not Lewis acid?
Answer» `BCl_(3)` `BeCl_(2)` `OVERSET(dot)CH_(3)` `UNDERSET(* )overset( )CH_(2)` SOLUTION :`H-underset(H)underset(\|)overset()C-H` cannot accept lp of `e^(-)`

Discussion

22.	Electron deficient molecular hydride is
Answer» `NH_(3)` `PH_(3)` `B_(2)H_(6)` `CH_(4)` Answer :C

Discussion

23.	Electronic configuration of a transition element is [Ar] 4s^23d^6. A sudden hike is observed between
Answer» `IP_(1) & IP_(2)` `IP_(2) & IP_(3)` `IP_(3) & IP_(4)` `IP_(4) & IP_(5)` Answer :C

Discussion

24.	Electron chemical reactions are generally ………………… .
Answer» REDUCTION reactions OXIDATION reactions Redox reactions Condensation reactions Answer :C

Discussion

25.	Electron affinity order of chalcogens is
Answer» `S GT SE gt TE gt PO` `O gt S gt Se gt Te gt Po` `S gt O gt Se gt Te gt Po` `O gt Po gt Tegt Se gt S` ANSWER :A

Discussion

26.	Electron affinity of the elements or ions shown correctly?
Answer» <P>`S GT O^(-)` `P gt N^(-)` `O^(-) gt S^(-)` `N^(-) gt P` ANSWER :A::B

Discussion

27.	Electron affinity of SF_(5) is among the highest known but that of SF_(6) is quite modest.
Answer» Solution : SULFUR in `SF_(6)` is saturated in terms of maximum covalency and maximum coordination number and so it has very little tendency to attract ELECTRON. In `SF_(5)` which is actually a FREE radical so it has got a very STRONG tendency to attract an electron to fulfill its covalency and co-ordination number. There fore the electron AFFINITY of `SF_(5)` is high.

Discussion

28.	Electron affinity of noble gases is :
Answer» Very high Low Almost zero High Answer :C

Discussion

29.	Electron affinity of :
Answer» CARBON is GREATER than oxygen sulphur is LESSER than oxygen iodine is HIGHER than bromine bromine is lesser than chlorine Answer :D

Discussion

30.	Electron affinity is positive when
Answer» `O^(-)` is formed from O `O^(2-)` is formed from `O^(-)` `O^(+)` is formed from O `O^(3-)` is formed from `O^(-)` SOLUTION :`O_((G))^(-)+E^(-) to O_(g)^(2-)+E,(DeltaH=ve, "Endothermic").`

Discussion

31.	Electron affinity for a noble gas is approximately equal to:
Answer» That of halogens Zero That of OXYGEN family That of NITROGEN famiy Answer :B

Discussion

32.	Electrometallurgy is employed for the extraction of
Answer» Cu Fe Na Ag Solution :Sodium is at higher position of ACTIVITY series haver LOW SRP.

Discussion

33.	Electrometallugical prosecss is used to extract
Answer» Fe Pb Na Ag Solution :Because Na is very reactive and can not be extracted by means of the reduction by `C,CO` ETC. So extracted by ELECTROLYSIS.

Discussion

34.	Electrometallurgical process is used to extract
Answer» Fe Pb NA Ag Solution :Because Na is very reactive and cannot be EXTRACTED by means of the reduction by C, CO ETC. So it is extracted by electrolysis.

Discussion

35.	Electrometallurgical process ( electrolysis of fused salt) is employed to extract :
Answer» IRON Lead Sodium Silver Answer :C

Discussion

36.	Electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodiumatom. Calculate the ionization energy of sodium atom. c= 3 xx 10^8 ms^(-1), h=6.626 xx 10^(-34) Js .
Answer» SOLUTION :`8.203 XX 10^(-22) KJ`

Discussion

37.	Electromagnetic radioation with maximum wavelength is
Answer» ULTRAVIOLET ray Radiowave X-ray Infrared Answer :B

Discussion

38.	Electrolytic refining is used to purify which of the following metals?
Answer» CU and ZN Ge and Si Zr and Ti Zn and Hg Solution :Both Cu and Zn can be PURIFIED by electro-refining.

Discussion

39.	Electrolytic refining is used to purify which of the following metals ?
Answer» Cu and Zn Ge and Si Zr and Ti Zn and Hg Solution :Cu and Zn is TAKEN as anode where PURE Cu and Zn are taken as cathode during electrolysis of Cu and Zn respectively. In REFINING of Cu, the electrolyte is `CuSO_4` while in CASE of zinc, the electrolyte is `ZnSO_4`.

Discussion

40.	Electrolyticrefiningis used to purify which of the following metals?
Answer» Cu and Zn Ge and Si Zr and Ti Zn and Hg Solution :Many , of the metals such as COPPER , SILVER , GOLD , aluminiun , lead , etc. are purified by ELECTROLYTIC REFINING.

Discussion

41.	Electrolyticrefining isusedto purifywhich ofthe followingmetals ?
Answer» CU andZn GeandSi ZR andTi ZnandHg ANSWER :A

Discussion

42.	Electrolytic reduction process is used for the altercation of
Answer» ALKALI metal Alkaline EARTH metals Aluminium All the above Answer :D

Discussion

43.	Electrolytic reduction with lead cathode of oxalic acid yields :
Answer» GLYCOLIC ACIDS Glyoxylic ACID Glycolic acid + glyoxylic acid `CH_3COOH` ANSWER :C

Discussion

44.	Electrolytic reduction of pure alumina is not possible because :
Answer» It is amphoteric It DISSOCIATES on fusion It MELTS at very HIGH temperature None of the above Answer :C

Discussion

45.	Electrolytic reduction of alumina to aluminium by the Hall-Heroult process is carried out
Answer» in the presence of NaCl in the presence of fluorite in the presence of CRYOLITE which FORMS a MELT at lower TEMPERATURE and increases the ELECTRICAL conductivity in the presence of cryolite which forms a melt at higher temperature and increases the electrical conductivity Answer :C

Discussion

46.	Electrolytic reduction of nitrobenzene in strongly acidic medium gives
Answer» aniline p-aminophenol m-nitroanline azoxybenzene Answer :B

Discussion

47.	Electrolytic reduction of alumina to aluminium by Hall-Heroult process is carried out :
Answer» in the presence of NaCI in the presence of fluorite in the presence of cryolite which FORM a metla with lower melting temperature in the presence of cryolite which FORMS a MELT with HIGHER melting temperature Answer :C

Discussion

48.	Electrolytic reduction of Al_(2)O_(3). Electrolyte (Al_(2)O_(3)+"cryolite") Anode: Graphite rods. What is wrong if anode is made of nickel instant of graphite?
Answer» Ni is costly Anode will be AFFECTED by produced `Cl_(2)` GRAPHITE remain unaffected by produced CO Nickel May be affected by high temperature. Answer :d

Discussion

49.	Electrolytic reduction of alumina to aluminium by Hall - Herault process is carried out
Answer» in the presence of NaCl in the presence of fluorite in the presence of cryolite which forms a melt with lower MELTING TEMPERATURE in the presence of cryolite which forms a melt with HIGHER melting temperature Solution :lectrolytic REDUCTION of alumina to aluminium is carried out in the presence of cryolite `(Na_(3) AIF_(6))` which decreases the M.pt of `Al_(2)O_(3)`

Discussion

50.	Electrolytic reduction method is used for :
Answer» highly ELECTROPOSITIVE METALS highly ELECTRONEGATIVE metals metalloids LANTHANIDES only Answer :A

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The electronic configuration of transition element "X", is +3, oxidation state is [Ar]3d^(5). What is its atomic number?

Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d^5.What is its atomic number?25,26,27,24.

Electronic configuration of a transition element X in + 3 oxidation state is [Ar]3d^5 What is its atomic number?

Electronic configuration of a transition element X in (+3) oxidation state is [Ar]3d^(5). What is its atomic number?

Electronic configuration of a transition element X in +3 oxidation state is [Ar] 3d^(5) . What is its atomic number ?

Electronic confriguration of a transition element X in +3 oxidation states is [Ar]3d^(5). What is its atomic number?

Electronic arrangement of pollonium is..........

Electrical conductance of metals decreases with increase in temperature.

Electronegtivity of beryllium is approximately equal to that of :

Electronic arrangement of Lv is...........

Oxyen is more eletrongative than sulphur, yet H_(2)S is acidic while H_(2)O in neutral.this is because:

Electronegativity of beryllium is approximately equal to that of

Electronegativity of an inert gas is :

Electron ________groups in phenol decrease its acidic strength.

Electron given enthalpies of halogens are largely negative. Give reasons.

Electron gain enthalpy of fluorine is less than that of chlorine. Why?

Electron gain enthalpies of noble gases are negative.

Electron gain energy is maximum in case of

Electron donating groups are,

Electron deficient molecular hydride is

Electronic configuration of a transition element is [Ar] 4s^23d^6. A sudden hike is observed between

Electron chemical reactions are generally ………………… .

Electron affinity order of chalcogens is

Electron affinity of the elements or ions shown correctly?

Electron affinity of SF_(5) is among the highest known but that of SF_(6) is quite modest.

Electron affinity of noble gases is :

Electron affinity of :

Electron affinity is positive when

Electron affinity for a noble gas is approximately equal to:

Electrometallurgy is employed for the extraction of

Electrometallugical prosecss is used to extract

Electrometallurgical process is used to extract

Electrometallurgical process ( electrolysis of fused salt) is employed to extract :

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodiumatom. Calculate the ionization energy of sodium atom. c= 3 xx 10^8 ms^(-1), h=6.626 xx 10^(-34) Js .

Electromagnetic radioation with maximum wavelength is

Electrolytic refining is used to purify which of the following metals?

Electrolytic refining is used to purify which of the following metals ?

Electrolyticrefiningis used to purify which of the following metals?

Electrolyticrefining isusedto purifywhich ofthe followingmetals ?

Electrolytic reduction process is used for the altercation of

Electrolytic reduction with lead cathode of oxalic acid yields :

Electrolytic reduction of pure alumina is not possible because :

Electrolytic reduction of alumina to aluminium by the Hall-Heroult process is carried out

Electrolytic reduction of nitrobenzene in strongly acidic medium gives

Electrolytic reduction of alumina to aluminium by Hall-Heroult process is carried out :

Electrolytic reduction of Al_(2)O_(3). Electrolyte (Al_(2)O_(3)+"cryolite") Anode: Graphite rods. What is wrong if anode is made of nickel instant of graphite?

Electrolytic reduction of alumina to aluminium by Hall - Herault process is carried out

Electrolytic reduction method is used for :