94420 + Interview Questions in Chemistry in Class 12

1.	For which of thefollowingores, frothfloatationprocess is applicable?
Answer» Oxide Sulphide CARBONATE SULPHATE ANSWER :B

Discussion

2.	For which of the following metal the carbon reduction cannot be used ?
Answer» LEAD MANGANESE Tungsten Iron SOLUTION :Mangames. W

Discussion

3.	For which of the following gaseous reactions, the relationship log K_C/K_P+"log RT = 0" will bne correct ?
Answer» `PCI_5 HARR PCI_3+CI_2` `SO_2 + O_2 hArr 2SO_3` `2NH_3 hArr N_2 +3H_2` `N_2 +O_2 hArr 2NO` ANSWER :A

Discussion

4.	For which of the following hybridisation the bond angle is maximum:
Answer» `sp_2` SP `sp^3 `dsp^2 Answer :B

Discussion

5.	For which of the following enzyme catalysed reaction, maltase is the suitable enzyme
Answer» STARCH`RARR`MALTOSE Maltose`rarr`Glucose Maltose`rarr`Starch Starch`rarr`Glucose Solution :ELECTROLYTIC refining is carried out for metals. Like `Cr,Sn,Pb,Ag,AU,Cu, Al`

Discussion

6.	For which of the following d^(n) configuration of octahedral complex(es), cannot exist in both high spin and low spin forms?
Answer» `d^(3)` `d^(5)` `d^(6)` `d^(8)` SOLUTION :IRRESPECTIVE nature of ligand, COMPLEX compound having `d^(1)` to `d^(3)` configuration-inner ORBITAL complex. Irrespective nature of ligand, complex compound having `d^(8)` to `d^(10)` configuration-outer orbital complex.

Discussion

7.	For which of the following DeltaE = DeltaH
Answer» `N_(2)O_(4)(G) iff 2NO_(2)(g)` `2SO_(2)(g)+O_(2)(g)iff2SO_(3)(g)` `H_(2)(g)+Cl_(2)(g)iff2HCl(g)` `H_(2)(g)+(1)/(2)O_(2)(g)iffH_(2)O(l)` Solution :`Deltan=0` for this reaction so, `DeltaE=DeltaH`

Discussion

8.	For which of the following d^(n) configuration of octahedral complex(es), cannot exist in both high spin and low spin forms ? (P) d^(3)""(Q) d^(5) (R ) d^(6)""(S) d^(8)
Answer» <P>Q and R P and R P and S R and S Solution :High SPIN and low spin, both are possible from `d^(4-7)` configuration

Discussion

9.	Forwhich of the following crystal would you expect assumption of anion-anion contact to be valid ?
Answer» CsBr NaF KCl Nal Answer :D

Discussion

10.	For which of the following compounds the number of compounds formed on monbromination are same-
Answer» `CH_(3)CH_(2)CH_(2)CH_(3)` `C(CH_(2)CH_(3))_(4)` `(CH_(3))_(2)CHCH_(2)CH_(3)` ANSWER :A::B

Discussion

11.	For which of the following compounds, the Lassaigne's test of nitrogen will fall ?
Answer» `NH_(2)CONHNH_(2)HCl` `NH_(2)NH_(2)2HCl` `H_(2)NCONH_(2)` `C_(6)H_(5)-N=N-C_(6)H_(5)` Answer :B

Discussion

12.	For which of the following compounds, Lassaigne's test of nitrogen fails?
Answer» Nitrobenzene Hydroxylamine Dimethylamine Hydrazine Solution :Hydroxylamine , `NH_2 OH` and hydrazine , `H_(2) N- NH_(2)` do not give Lassaigne.s test for nitrogen . As no carbon is present in these COMPOUNDS , the sodium extract obtained in these cases do not contain any NaCN.

Discussion

13.	For which of the following compounds Lassaigne's test of nitrogen will fail ?
Answer» `H_2N CO NH NH_2 * HCL` `H_(2) N NH_(2) * 2HCl` `H_(2) N CONH_(2)` `C_(6) H_(5) - N = N - C_(6) H_(5)` SOLUTION :`H_(2) N NH_(2) *2HCl` does not contain carbon , hence does not give positive results for Lassaigne.s test for nitrogen.

Discussion

14.	For which of the following compound, a graph of molar conductivity and ("molarity")^(1/2) is obtained straight line ?
Answer» CsCl `NH_(4)OH` ``HCOOH `CH_(3)COOH` Solution :CsCl is STRONG ELECTROLYTE.

Discussion

15.	For which of following reduction, ore should be partially roasted is :-
Answer» Smelting Auto reduction Alumino thermite process METAL DISPLACEMENT ANSWER :B

Discussion

16.	For which kind of reaction is the rate law predicted by the law of mass action the same as that obtained from experiment ?
Answer» Solution :For a reaction occurring in a SINGLE STEP , the experimentally FOUND rate law and the rate law predicted by the law of MASS action are the same.

Discussion

17.	For which lanthanoids, (+2) and(+3) oxidation states are common ?
Answer» Na La Ce Eu Answer :D

Discussion

18.	For which element the inertness of the electron pair will not be observed
Answer» SN FE Pb In Solution :Inert pair effect is EXHIBITED only by heavy metals of p-blocks ELEMENTS.

Discussion

19.	For which element would XH_(3) be a stable species?
Answer» C Cl P S Solution :`PH_(3)` is STABLE. (OCTET RULE)

Discussion

20.	For which crystal system, all four type of unit cell may exist ?
Answer» RHOMBOHEDRAL MONOCLINIC TRIGONAL ORTHORHOMBIC ANSWER :D

Discussion

21.	For which Delta_(f)H^(Theta) is zero?
Answer» `H` `H^(-)` `H^(+)` `H^(+)(AQ)` ANSWER :D

Discussion

22.	For which crystal anion-anion contact is valid?
Answer» NaF NaI CsBr KCI Answer :A

Discussion

23.	For which change triangleHnetriangleU:
Answer» `H_2+I_2⇌2HI` `HCl+NaOHrarrNaCl+H_2O` `C(s)+O_2(G)⇌CO_2(g)` `N_2+3H_2rarr2NH_3` ANSWER :D

Discussion

24.	For which change DeltaH ne DeltaE :
Answer» `H_(2)+I_(2)rarr2HI` `HCl+NaOHrarrNaCl` `C_((s))+O_(2(g))rarrCO_(2(g))` `N_(2)+3H_(2)rarr2NH_(3)` Solution :`DELTAH=DeltaE+DeltanRT` `therefore` For `DeltaH NE DeltaE. DELTAN ne 0` `Deltan=0` for reaction (a) as both reactants & PRODUCTS have same no. of molecules `Deltan=0` for (c ) as C is in solid state. Further `DeltaH=DeltaE` for reaction (B) as it is carried out in liquid state Moreover `Deltan=0` for this reaction also, `HCl+NaOHrarrNaCl+H_(2)O`.

Discussion

25.	For which cell emfis independent of the concentration of electrolytes used :
Answer» `FE[FEO(s)]KOH(aq)[NiO(s)[Ni_2O_3(s)]Ni` `Pt(H_2)[HCI](Cl_2)` `Zn[Zn(NO_3)_2][CuSO_4]Cu` `Hg,HgCl_2[KCI][AgNO_2]Ag` ANSWER :A

Discussion

26.	For which among the following equimolar aqueous solutions vant' Hoff factor has the lowest value?
Answer» Solution :Urea is NONELECTROLYTE, i=1 (a) `AlCl_(3), i=4`, b) `K_(2)SO_(4), i=3`, (c )` NH_(4)Cl, i=2`

Discussion

27.	For which case ' lambda' values v/ssqrt(c) shows a straight line
Answer» KCl HCOOH `CH_3NH_2` `CH_3COOH` ANSWER :A

Discussion

28.	For which among the following reactions, change in entropy is less than zero?
Answer» SUBLIMATION of Iodine Dissociation of Hydrogen Formation of Hydrogen Thermal decomposition of Calcium Carbonate SOLUTION :The formation of water. `H_(2)(g) + O_(2)(g) to H_(2)O(l)` `DeltaS = sumS_("Products") -sum S_("reactants")` An Entropies of reactants are more than products Hence `DeltaS` is negtive. (a) For sublimation of Iodine `I_(2)(g) to 2I_(g)DeltaS = +ve` (b) Dissociation of hydrogen `H_(2)(g) to 2H(g)``DeltaS=+ve` (d) Thermal decomposition of `CaCO_(3)` `CaCO_(3)(s) to CaO(s) + CO_(2)(g), DeltaS= +ve`

Discussion

29.	For what minimum value of n, polymerisation isomers of [Fe(NH_(3))_(3)(NO_(2))_(3)]_(n) would not exist ?
Answer» ANSWER :6

Discussion

30.	For weak electrolyte, sudden increase in molar conductance with dilution. Prove this statement.
Answer» SOLUTION :For a weak electrolyte, at high CONCENTRATION the plot is almost parallel to concentration axis with slight increase in CONDUCTIVITY as the dilution INCREASES. When the concentration approaches zero, there is a sudden increase in the molar conductance and the curve is a almost parallel to `Lambda_m` axis. This is due to the fact that the DISSOCIATION of the weak electrolyte increases with the increase in dilution (Ostwald.s dilution law).

Discussion

31.	For weak acid strong base titration the indicator used is :
Answer» POTTASIUM DICHROMATE METHYL orange Litmus Phenolphthalein Answer :D

Discussion

32.	For vaporization of water at 1 atmospheric pressure, the values of DeltaH and DeltaS are 40.63 kJ mol^(-1) and 108.8 JK^(-1)mol^(-1), respectively. The temperature when Gibbs energy change (DeltaG) for this transformation will be zero, is
Answer» 273.4 K 393.4 K 373.4 K 293.4 K Solution :`DeltaG=DeltaH-TDeltaS` `DeltaG=0` `DeltaH=TDeltaS`, `T=(40.63xx10^(3))/(108.8)=373.4 K`.

Discussion

33.	For unknown reaction half mole of reactant of total 2 moles reactant is converted in to product time is taken 1 hour.Then calculate how many moles of reactant is present after 4 hours?
Answer» 0.225 MOLE 0.425 mole 0.125 mole 0 Solution :2 mole `to` for 1 mole After 1 HOUR `tot_((1)/(2))` HR. After 1 hour `(1)/(1)` mole `t_((1)/(2))`=1Hour so After 2 hour 0.5 mole `therefore` every `t_((1)/(2))` time After 3 hour 0.250mole After 4 hour 0.125 mole

Discussion

34.	For two volatile liquid A and B if the vapour pressure ratio of P_(A)^(0) : P_(B)^(0)=1:2 and X_(A):X_(B)=1 : 2, then find out mole fraction of component A in vapour state ?
Answer» ANSWER :`0.20`

Discussion

35.	For two reactions, I: A to B """Rate constant"=k_(1)sec^(-1) II: C to D """Rate constant"=k_(2) M^(-1)sec^(-1) Starting with initial concentration of 1M each, time taken to reach to 0.5M is same, then, identify the correct options.
Answer» `k_(1)gtk_(2)` `k_(1)lt k_(2)` Rate of FIRST reaction at 0.5M concentration gt rate of second reaction at 0.5M concentration. INITIAL rate of first reaction lt initia rate of second reaction. Answer :B::C::D

Discussion

36.	For two mole of an ideal gas:
Answer» `(C_p-C_v)=R` `(C_p-C_v)=R/2` `(C_v-C_p)=-2R` `(C_p-C_v)=0` ANSWER :A

Discussion

37.	For two ionic solids KI and CaO, identify the wrong statement among the following :
Answer» LATTICE ENERGY of CaO is much higher than that of KI KI is SOLUBLE in benzene CaO has HIGH m.p KI has high m.p Answer :D

Discussion

38.	For two gases A and B,P v//s V isothermsare drawn at T K as shown, T_(A)& T_(B) are critical temepratures of A & B respectively Which of the following is true ?
Answer» `T_(A) lt T lt T_(B)` `T_(A) gt T gtT_(B)` `T_(A) gtT_(B) gt T` NONE of above ANSWER :A

Discussion

39.	For two gases A and B with molecular weights M_(A) and M_(B), it is observed that at a certain temperature T_(1) the mean velocity of A is equal to the root mean square velocity of B, thus the mean velocity of A can be made equal to the mean velocity of B if
Answer» A is at TEMPERATURE T and B at T', `T gt T'` A is lowered to a temperature `T_(2), T_(2) lt T` while B is at T Both A and B are raised to a HIGHER temperature Both A and B are placed at lower temperature Solution :`(U_(AV))_(A)=sqrt((8RT)/(piM_(A))) and (U_(rms))_(B)=sqrt((3RT)/(M_(B)))` `THEREFORE (8)/(3pi) =(M_(A))/(M_(B))` For `A (U_(AV))=sqrt((8RT_(2))/(piM_(A)))" or "B V_(AV)=sqrt((8RT)/(piM_(B)))` `(T_(2))/(T) =(M_(A))/(M_(B))=(8)/(3pi) therefore T_(2) =(8)/(3pi) T" or "T_(2) lt T` Hence, (B) is the correct ANSWER.

Discussion

40.	For two gases A and B,P v//s V isothermsare drawn at T K as shown, T_(A)& T_(B) are critical temepratures of A & B respectively. The correct statement(s) is //are (I) Pressure correction term will be more negligible for gas B at T K. (II) The curve for gas 'B' will be of same shape as for gas A if T gt T_(B) (III) Gas 'A' will show same P v//s V curve as of gas 'B' if T gt T_(A)
Answer» III only II and III II only All ANSWER :C

Discussion

41.	For two chemical reactions : A+2Brarr3C,""DeltaH=-400kJ//"mole of A" 2D+Erarr2F,""DeltaH=+300kJ//"mole of E" occuring in container such that temperature does not change. What should be the rate of formation of 'F' if rate of disappearance of B is 10^(-3) M/sec?
Answer» `10^(-3)M//sec` `8XX10^(-2)M//min` `(4)/(3)xx10^(-3)M//min` `4xx10^(-3)M//sec` Answer :D

Discussion

42.	For two different acids with same concentration
Answer» The relative strngth is expressed as `(alpha_(1))/(a_(2))` Relative strength is expressed as `(K_(a_(1)))/(K_(a_(2)))` Relative strength is expressed as `SQRT((K_(a_(1)))/(K_(a_(2))))` `(pH_(1))/(pH_(2))` Solution :Let `alpha_(1), and alpha_(2)` be the degree of dissociation of TWO acids and `alpha_(1),alpha_(2)` are very small when compared to unity. `(calpha_(1)^(2))/(1-alpha_(1))=K_(a_(1)),(calpha_(2)^(2))/(1-alpha_(2))=K_(a_(2))impliessqrt((K_(a_(1)))/(K_(a_(2))))=(alpha_(1))/(alpha_(2))=` relative strength Hence choices (a) and (B) and (c) are correct while (b) and (d) are incorrect.

Discussion

43.	For two acids A and B, K_a values at 25^@ C are2xx10^6 and 1.8xx 10^(-4) respectively. Which among the following is true with respect to the above data.
Answer» A and B are equally acidic A is stronger then B B is stronger than A `K_a` value is not a MEASURE of acid strength Answer :B

Discussion

44.	For two acids A and B, pK_(a) = 1.2, pK_(b) = 2.8 respectively in value , then which is true
Answer» A and B both are EQUALLY acidic A is strongly than A B is STRONGER than A Neither A nor B is strong Solution :The VALUE of `pK_(a)` for strong acid is less.

Discussion

45.	For Trigonal system, axial rations are a = b = cand the axial angles are k
Answer» `alpha = beta = gammane 90^(@)` `alpha = beta = gamma= 90^(@)` `alpha = gamma = 90^(@), beta ne 90^(@)` `alpha ne beta ne gamma ne 90^(@)` SOLUTION : For TRIGONAL or RHOMBOHEDRAL system, `alpha = beta = gamma ne 90^(@)`

Discussion

46.	For this graph which option is correct?
Answer» At less than `1500^(@)C`, Mg acts as REDUCING agent for `SiO_(2)` At more than `1500^(@)C`, SI acts as reducing agaent for MgO Both a and b None of these Answer :C

Discussion

47.	For the vulcanization of natural rubber, ................... is used and heated to 100^(@)-150^(@)C
Answer» SOLUTION :SULPHUR

Discussion

48.	For the two reactions I:toBII I:toB,II:CtoD following graph is obtained. Which of the following is true:
Answer» If [B]=[A] then at than TIME [D]`=0.75 M` If [C]=[A] then at that time `[B]gt[D]` `(t_(100%))_("ReactonI")=(t_(100%))_("REACTION"II)` [A]=[C]at`t=sqrt(3)/(2)MIN.` Answer :A

Discussion

49.	For the thermochemical equation, 2H_(2(g)) + O_(2(g)) rarr 2H_(2)O_(l) , Delta H = - 571.6 kJ Heat of decomposition of water is :
Answer» `- 571.6 kJ` `+ 571.6 kJ` `- 1143.2 kJ` `+ 285.8 kJ` Solution :`2H_(2) (g) + O_(2) (g) rarr 2H_(2)O (L) , Delta H = - 571.6 kJ` or `H_(2)(g) + O_(2)(g) rarr H_(2)O(l), Delta H = (-571.6)/(2) = - 285.8 kJ` For decomposition of WATER `H_(2)O(l) rarr H_(2)(g) + O_(2) (g) Delta h = + 285.8 kJ`

Discussion

50.	For the tetrahedral complex [MnBr_(4)]^(2-) the spin only magnetic moment value is…. (Atomic No.Of Mn=25)
Answer» 1.7 5.9 4.8 2.4 Solution :Oxidation number is `+2(MN^(+2))` in `[MnBr_(4)]^(2-)` `:. 5` unpaired ELECTRONS in `Mn^(+2)` `:. mu= sqrt(5(5+2))BM = 5.9`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

For which of thefollowingores, frothfloatationprocess is applicable?

For which of the following metal the carbon reduction cannot be used ?

For which of the following gaseous reactions, the relationship log K_C/K_P+"log RT = 0" will bne correct ?

For which of the following hybridisation the bond angle is maximum:

For which of the following enzyme catalysed reaction, maltase is the suitable enzyme

For which of the following d^(n) configuration of octahedral complex(es), cannot exist in both high spin and low spin forms?

For which of the following DeltaE = DeltaH

For which of the following d^(n) configuration of octahedral complex(es), cannot exist in both high spin and low spin forms ? (P) d^(3)""(Q) d^(5) (R ) d^(6)""(S) d^(8)

Forwhich of the following crystal would you expect assumption of anion-anion contact to be valid ?

For which of the following compounds the number of compounds formed on monbromination are same-

For which of the following compounds, the Lassaigne's test of nitrogen will fall ?

For which of the following compounds, Lassaigne's test of nitrogen fails?

For which of the following compounds Lassaigne's test of nitrogen will fail ?

For which of the following compound, a graph of molar conductivity and ("molarity")^(1/2) is obtained straight line ?

For which of following reduction, ore should be partially roasted is :-

For which kind of reaction is the rate law predicted by the law of mass action the same as that obtained from experiment ?

For which lanthanoids, (+2) and(+3) oxidation states are common ?

For which element the inertness of the electron pair will not be observed

For which element would XH_(3) be a stable species?

For which crystal system, all four type of unit cell may exist ?

For which Delta_(f)H^(Theta) is zero?

For which crystal anion-anion contact is valid?

For which change triangleHnetriangleU:

For which change DeltaH ne DeltaE :

For which cell emfis independent of the concentration of electrolytes used :

For which among the following equimolar aqueous solutions vant' Hoff factor has the lowest value?

For which case ' lambda' values v/ssqrt(c) shows a straight line

For which among the following reactions, change in entropy is less than zero?

For what minimum value of n, polymerisation isomers of [Fe(NH_(3))_(3)(NO_(2))_(3)]_(n) would not exist ?

For weak electrolyte, sudden increase in molar conductance with dilution. Prove this statement.

For weak acid strong base titration the indicator used is :

For vaporization of water at 1 atmospheric pressure, the values of DeltaH and DeltaS are 40.63 kJ mol^(-1) and 108.8 JK^(-1)mol^(-1), respectively. The temperature when Gibbs energy change (DeltaG) for this transformation will be zero, is

For unknown reaction half mole of reactant of total 2 moles reactant is converted in to product time is taken 1 hour.Then calculate how many moles of reactant is present after 4 hours?

For two volatile liquid A and B if the vapour pressure ratio of P_(A)^(0) : P_(B)^(0)=1:2 and X_(A):X_(B)=1 : 2, then find out mole fraction of component A in vapour state ?

For two reactions, I: A to B """Rate constant"=k_(1)sec^(-1) II: C to D """Rate constant"=k_(2) M^(-1)sec^(-1) Starting with initial concentration of 1M each, time taken to reach to 0.5M is same, then, identify the correct options.

For two mole of an ideal gas:

For two ionic solids KI and CaO, identify the wrong statement among the following :

For two gases A and B,P v//s V isothermsare drawn at T K as shown, T_(A)& T_(B) are critical temepratures of A & B respectively Which of the following is true ?

For two gases A and B with molecular weights M_(A) and M_(B), it is observed that at a certain temperature T_(1) the mean velocity of A is equal to the root mean square velocity of B, thus the mean velocity of A can be made equal to the mean velocity of B if

For two chemical reactions : A+2Brarr3C,""DeltaH=-400kJ//"mole of A" 2D+Erarr2F,""DeltaH=+300kJ//"mole of E" occuring in container such that temperature does not change. What should be the rate of formation of 'F' if rate of disappearance of B is 10^(-3) M/sec?

For two different acids with same concentration

For two acids A and B, K_a values at 25^@ C are2xx10^6 and 1.8xx 10^(-4) respectively. Which among the following is true with respect to the above data.

For two acids A and B, pK_(a) = 1.2, pK_(b) = 2.8 respectively in value , then which is true

For Trigonal system, axial rations are a = b = cand the axial angles are k

For this graph which option is correct?

For the vulcanization of natural rubber, ................... is used and heated to 100^(@)-150^(@)C

For the two reactions I:toBII I:toB,II:CtoD following graph is obtained. Which of the following is true:

For the thermochemical equation, 2H_(2(g)) + O_(2(g)) rarr 2H_(2)O_(l) , Delta H = - 571.6 kJ Heat of decomposition of water is :

For the tetrahedral complex [MnBr_(4)]^(2-) the spin only magnetic moment value is…. (Atomic No.Of Mn=25)