52671 + Interview Questions in Chemistry in Class 11

1.	If in a reaction at constant temperature, n_(1) moles of the gaseous reactants change inton_(2) moles of gaseous products , the difference in the enthalpy change and internal energy change of the reaction will be equal to "….............".
Answer» Solution :`DELTAH- DeltaV = (n_(2)-n_(1))RT =Deltan_(G)RT`

Discussion

2.	If in a mixture where Q = K , then what happens ?
Answer» the reaction shift towards products the reaction shift towards REACTANTS NOTHING appears to happen , but forward and reverse reactions are continuing at the same rate nothing happens SOLUTION :nothing appears to happen , but forward and reverse reactions are continuing at the same rate

Discussion

3.	If in a mixture where O = K, then what happens?
Answer» the reaction shift TOWARDS products the reaction shift towards reactants nothing appears to HAPPEN, but forward and REVERSE reactions are CONTINUING at the same rate nothing happens Answer :C

Discussion

4.	If (I)C + O_2 rarr CO_2 , Q_1 (II) C+1//2 O_2 rarr CO , Q_2 (III) CO + 1//2O_2 rarr CO_2 , Q_3 The heats of reaction Q_1 and Q_2 are -12, -10 respectively. Then Q_3 is
Answer» `-2` `2 ` ` –22` ` –16` ANSWER :A

Discussion

5.	If I_(2)is dissolved in aqueous KI, the intense yellow species , I_(3)^(-) , is formed. The structure of I_(3)^(-) ion is
Answer» SQUARE pyramidal TRIGONAL bipyramidal OCTAHEDRAL PENTAGONAL biypramid Answer :B

Discussion

6.	If I_(1), I_(2)and I_(3) etc. represent the successive ionization potentials of an atoms then the correct order is :
Answer» `I_(1)GT I_(2)gt I_(3)` `I_(1)LT I_(2)gt I_(3)` `I_(3)gt I_(2)gt I_(1)` `I_(2)gt I_(1)gt I_(3)` ANSWER :C

Discussion

7.	If I and E are ionisation energy and electron affinity of an element in kJ "mole"^(-1) electronegativity is given as
Answer» `(I+E)/(2)` `(I+E)/(5.6)` `(I+E)/(129)` `(I+E)/(544)` ANSWER :D

Discussion

8.	If hydrogen ion concentration in a solution is 1xx10^(-5) moles/litre, calculate the concentration of OH^(-)ion in this solution (K_(w)=10^(-14) "moles"^(2)//"litre"^(2))
Answer» ANSWER :`10^(-9)` moles/litre

Discussion

9.	If Hydrogen Chloride gas is passed through saturated solution of sodium chloride which precipitate will be obtained ?
Answer» HCl NaCl (A) and (B) Both None of these ANSWER :B

Discussion

10.	If Hunds rule is not obeyed by some elements given below then which atom has maximum magnetic moment
Answer» `FE` `Cu` `Cr` `MN` ANSWER :C

Discussion

11.	If HNO_(3) changes into N_(2)O, the oxidation number is changed by
Answer» `+2` `-1` 0 `+4` ANSWER :D

Discussion

12.	If heterolytic and hemolytic cleavage of bond then which type of reaction occurs?
Answer» Solution :The ORGANIC reaction which proceed through heterolytic BOND cleavage are called ionic or POLAR or heteropolar type. (It is electrophilic, NUCLEOPHILIC and elimination type reaction). If the organic reaction, which proceed by homolytic fission are called free RADICAL or homopolar or nonpolar reactions

Discussion

13.	If helium is allowed to expand in vacuum, it liberates heat because
Answer» Helium is an inert gas Helium is an ideal gas The CRITICAL temperature of helium is very low Helium is ONE of the lightest gases ANSWER :A::C

Discussion

14.	If heat of formation of HI in the given reactions (i) H_(2)(g) + I_(2) to I_(2)(s) to 2HI (ii) H_(2)(g) +I_(2)(g)to 2HI(g) are 26 KJ and -4.5 "mol"^(-1) + respectively , then the heat of sublimation of iodine is
Answer» 30.5 KJ 61.0 KJ 21.5 KJ `-30.5 KJ` Solution :In order to GET enthalpy of SUBLIMATION multiply the heat of FORMATION given for per mole by 2 and then subtract (ii) and (i) `DeltaH=26xx2-(-4.5xx2)=61.0` KJ

Discussion

15.	If heat of dissociation of CHCl_(2)COOK+H_(2)O is 0.7 kcal//mole then, DeltaH for the reaction : CHCl_(2)COOH+KOHtoCHCl_(2)COOK+H_(2)O
Answer» `-13 KCAL` `+13 kcal` `-14.4 kcal` `-13.7 kcal` ANSWER :A

Discussion

16.	If [H_3O^+]=3.5xx10^(-8) , So calculate [OH^-] and pH of solution.
Answer» SOLUTION :`[OH^-]=2.85xx10^(-7)` M PH = 7.45

Discussion

17.	If [H^+]=1.67xx10^(-10) M in solution than calculate [OH^-].
Answer» SOLUTION :`[OH^-]=K_w/([H^+])=(1.0xx10^(-14))/(1.67xx10^(-10))=5.0112xx10^(-5)`

Discussion

18.	If gas having more critical temperature, then its liquification will be …………
Answer» SLOW fast FIRST (B) and (C ) both Answer :A::B::C::D

Discussion

19.	If gas has a RMS velocity 5.2 xx 10^4 cms^(-1) , find the average and most probable velocities of the gas
Answer» ANSWER :`4.79 XX 10^4, 4.25 xx 10 CM^(-1)`

Discussion

20.	If for two gases of molecular weights M_(A) and M_(B) at temperature T_(A) and T_(B):T_(A)M_(B)=T_(B)M_(A), then which property has the same magnitude for both the gases?
Answer» DENSITY Pressure KE PER mol rms speed Answer :d

Discussion

21.	If for an ideal gas, the ratio of pressure and volume is constant and is equal to 1 atm L^(-1) , the molar heat capacity at constant pressure would be
Answer» `(3)/(2)R` `2R` `(5)/(2)R` zero Solution :By definition, `H=E+PV` `((dH)/(DT))_(P)=((dE)/(dT))_(P)+P((dV)/(dT))_(p)=C_(p),m` For the given IDEAL gas, we will have `PV=RT` or `V^(2)=RT` or `2V((dV)/(dT))_(P)=R` or `((dV)/(dT))_(P)=(R)/(2V)` `E=(3RT)/(2)` or `((dE)/(dT))_(P)=(3)/(2)R=C_(v),m` `C_(P),m=(3)/(2)R+Pxx(R)/(2V)=((3)/(2)+(1)/(2))R=2R`

Discussion

22.	If for a particular reaction, the difference in the heat evolved when the reaction is carried out at constant pressure andthat at constant volume at 27^(@)C is nearly5 kJ mol^(-1) , then the difference in the number of moles of gaseouseactants and products is
Answer» ANSWER :2

Discussion

23.	If for a chemical reaction Delta C_(p) I stemperature of reactants of this reaction bya certain amount =q_(1) and heat required to increase temperature of products of the same reaction by same amount =q_(2), then:
Answer» `q_(1)gtq_(2)` `q_(1)ltq_(2)` `q_(1)=q_(2)` `q_(1)` may or may not be equal to `q_(2)` will depend on NATURE of REACTANTS and products . Answer :a

Discussion

24.	If for 2A_2B(g) hArr 2A_2(g)+B_2(g), K_p=TOTAL PRESSURE (at equilibrium ) and starting the dissociation from 4 mol of A_2B then:
Answer» degree of DISSOCIATION of `A_2B`will be (2/3) TOTAL no of moles at EQUILIBRIUM will be (14/3) at equilibrium the no of moles of `A_2B` are not EQUAL to the no of moles of `B_2` at equilibrium the no of moles of `A_2B` are equal to the no of moles of `A_2` Answer :A

Discussion

25.	If the first excitation potential of a hypothetical hydrogen like atom is 15 V, then the third excitation potential of the atom is
Answer» 10.2 V 12 V 14 V 16 V SOLUTION :IP` = 13.6 Z^2 = 16` (given) `1^(st)` excitation potential `= 13.6 xx 3/4 xx Z^2` `= 16 xx 3/4 = 12 V`

Discussion

26.	If excess of Ca(OH)_2is added to hard water in Clark's method
Answer» TEMPORARY HARDNESS is not REMOVED Permanent hardness is removed Temporary hardness OCCURS Permanent hardness occurs ANSWER :D

Discussion

27.	If excess CO_(2) gas is passed in 0.205 mole Ba(OH)_(2) then give the amount of BaCO_(3)produced.
Answer» 81 g 40.5 g 20.25 g 162 g Solution :`{:(Ba(OH)_(2),+,CO_(2),rarr,BaCO_(2),+,H_(2)O),("1 mole",,,,"1mole",,),("0.205 mole",,,,"0.205 mole",,):}` Molecular MASS of `BaCO_(3) = 137+12+48` `= 197 g "mole"^(-1)` Weight of `BaCO_(3) = 197 xx 0.205 = 40.385g`

Discussion

28.	If ethanol containing EtOD is used as solvent , then deuterium exchange take place in E1cB mechanism . Why ?
Answer» Answer :In E1CB MECHANISM CARBANION is formed as intermediate and 1ST step is reversible

Discussion

29.	If E_(Sn^(2+)//Sn)^(@)=-0.14V, what would be the value of E_(Sn//Sn^(2+))^(@)?
Answer» SOLUTION :`+0.14` VOLTS

Discussion

30.	If equilibrium constant for the reaction N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g) at 298 K is 2.54 , the value of equilibrium constant for the reaction (1)/(2) N_(2) + (3)/(2) H_(2) hArr NH_(3) will be ……..
Answer» Solution :`K_(P)` for `N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g) = ((P_(NH_(3)))^(2))/(P_(N_(2)) xx (P_(H_(2)))^(3)) = 2.54` `K.._(P)` for `(1)/(2) N_(2) (g) + (3)/(2) H_(2) (g) hArr NH_(3) = ((P_(H_(3))))/((P_(N_(2)))^((1)/(2)) xx (P_(H_(2)))^((3)/(2)))` SINCE the REACTION is halved `K.._(p) = SQRT(K._(p)) = sqrt((2.54)) = 1.59`

Discussion

31.	Number of phases present in the following thermodynamic systems are: (a) NH_(4) HS_((s)) hArr NH_(3(g)) + H_(2)S_((g)) (b) CaCO_(3(s)) hArr CaO_((s)) + CO_(2(g)) (c ) N_(2(g)) + 3H_(2(g)) hArr 2NH_(3(g))
Answer» `I gt III gt II` `I= III LT II` `II gt III gt I` `II gt I gt III` Answer :C

Discussion

32.	If equal weights of oxygen and nitrogen are placed in separate containers of equal volume as the same temperature, which one of the following statements is true? (mol wt. N_(2)=28,O_(2)=32)
Answer» Both flasks contains the same NUMBER of molecules. The pressure in the nitrogen flask is greater than the one in the OXYGEN flask. More molecules are PRESENT in the oxygen flask. The nitrogen has a greater average KINETIC energy PER mole. Answer :b

Discussion

33.	If equal volume of 1M KMnO_(4) " and" 1M K_(2)Cr_(2)O_(7) solutions are allowed to oxidise Fe^(2+) " to " Fe^(3+) in acidic medium, then Fe^(2+) will be oxidised :
Answer» more by `KMnO_(4)` more by `K_(2)Cr_(2)O_(7)` EQUAL in both cases cannot be determined Answer :A

Discussion

34.	If equal amounts of ether, acetone and bezene are placed in identical petri dishes, in which order, they will evaporate off and why ?
Answer» SOLUTION :Ether will EVAPORATE off first of all and benzene LAST of all. This is because intermolecular FORCES of attraction are weakest in ether and strongest in benzene and inbetween in CASE of acetone.

Discussion

35.	If E_(n) = -313.6//n_2, if the value of E_1 = -34.84 to which value 'n' corresponds
Answer» 4 3 2 1 Answer :B

Discussion

36.	If electron is added to group 16, 17 which orbit n = 2 and n = 3 shows less electron electron repulsion ? Why?
Answer» SOLUTION :N = 3 because volume of n = 3 is more so repulsion is less.

Discussion

37.	If electron transitsfrom n=5 to n=2it belongwhichseries.?
Answer» SOLUTION :n=2balmerseriesand belongto visiblespectru.

Discussion

38.	Ifelectron is removedfrom an atom then isenergy
Answer» DECREASES INCREASES remainsame NONE ANSWER :B

Discussion

39.	If electronis acceleratedby 1.0 xx 10^(4)voltthancalculatekineticenergyfrequencyand wavelength
Answer» Solution :`KE = 1.602 xx 10^(15) lambdav= 5.933 xx 10 HZ ` `lambda= 1.22xx 10^(11) m`

Discussion

40.	If electrical conductivity is found to be same in all directions through a solid, the substance is _______ solid and this property is called _______
Answer» ANSWER :AMORPHOUS, ISOTROPY

Discussion

41.	If electrical conductivity is found to be same in all directions through a solid, the substance is _____ solid and thisproperty is called ________\
Answer» ANSWER :AMORPHOUS SILICA

Discussion

42.	If each hydrogen atom in the ground state, 1.0 inole of H atoms are excited by absrobing photons of energy 8.4 eV, 12.09 eV and 15.0 eV of energy, then the number of spectral lines emitted is equal to
Answer» SOLUTION :By absorbing 8.4 ev not excited By absorbing 15eV , it is ionised . So, only POSSIBLE is 12.09eV. `Delta E =-13.6 + 12.09 =-1.5 eV` i.e., n=3

Discussion

43.	If E_(1), E_(2) and E_(3) represent respectively the kinetic energies of an electron, an alpha-particle and a proton each having same de Broglie wavelength, then
Answer» `E_(1) gt E_(2) gt E_(3)` `E_(3) gt E_(2) gt E_(1)` `E_(1) gt E_(3) gt E_(2)` `E_(1) = E_(2) = E_(3)` SOLUTION :`K.E. = (1)/(2) MV^(2) and lamda = (h)/(mv) or V = (h)/(m lamda)` `:. K.E. = (1)/(2) m (h^(2))/(m^(2) lamda^(2)) = (h^(2))/(2m lamda^(2))` As `lamda` is same for given particles, `E PROP (1)/(m)` But `m_(e) lt m_(H^(+)) lt m_(alpha)` Hence, `E_(1) gt E_(3) gt E_(2)`

Discussion

44.	IfE_1, E_2 and E_3 represent respectively the kinetic energies of an electron, an alpha particle and a proton respectively each having same deBroblie wavelength then which is incorrect relation?
Answer» <P>`E_1 GT E_3 gt E_2` `E_2 gt E_3 gt E_1` `E_1 gt E_2 gt E_3` `E_1 = E_2 = E_3` SOLUTION :`lambda_e = lambda_x = lambda_p` `impliesh/((mv)_2) = h/((mv)_x) = h/((mv)_P) therefore lambda alpha 1/(sqrt(KE.m))`

Discussion

45.	If E= number of Ione pairs of electrons of Xe B=the number of boding pairs of electrons S=shape of the molecule then, the correct set of E,B and S of XeF_(4)
Answer» `{:(""E""B""S),(1." "4""2"""Square PLANAR"):}` `{:(""E""B""S),(2." "3""3"""octahedral"):}` `{:(""E""B""S),(3." "3""3"""Square planar"):}` `{:(""E""B""S),(4." "2""4"""Square planar"):}` Answer :D

Discussion

46.	If distance between two molecules of gases becomes half then which type of changes occurs in London forces ?
Answer» Solution :London FORCES `prop (1)/(r^(6))= k (1)/(r^(6))` Initially London force `= x_(1)=k(1)/(r^(6))` Initial distasnce = r FINAL distance `= (r )/(2)` Final london force `x_(2)=k(1)/(((r )/(2))^(6))=k(2^(6))/(r^(6))` `(x_(2))/(x_(1))=((k.2^(6))/(r^(6)))xx((r^(6))/(k))` `= 2^(6)=2xx2xx2xx2xx2xx2 = 64` times

Discussion

47.	If dissociation for reaction PCl_(5) hArr PCl_(3) + Cl_(2) is 20% at 1 atm pressue . Calculate the value of K_(C).
Answer» `0.04` `0.05` `0.07` `0.06` SOLUTION :`K_(C) = ([PCl_(3)][Cl_(2)])/([PCl_(5)]) = ([(20)/(100)] xx [(20)/(100)])/([(80)/(100)]) = (0.2 xx 0.2 )/(0.8) = (0.04)/(0.8) = 0.05`

Discussion

48.	If DeltaH lt T Delta S at 298K temperature, what will be the value of equilibrium constant ?
Answer» SOLUTION :If `DeltaG lt 0`, the value of EQUILIBRIUM CONSTANT will be more than 1.

Discussion

49.	If DeltaG=0 , then the process is ___
Answer» SOLUTION :EQUILIBRIUM

Discussion

50.	If DeltaG^@ for the reaction given below is 1. kJ, the equilibrium constant for a reaction. 2HI_((g)) harr H_(2(g))+I_(2(g)) at 25^@C is :
Answer» 24 3.9 2 0.5 Solution :`DELTA G^(@) = RT` In K

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

If in a reaction at constant temperature, n_(1) moles of the gaseous reactants change inton_(2) moles of gaseous products , the difference in the enthalpy change and internal energy change of the reaction will be equal to "….............".

If in a mixture where Q = K , then what happens ?

If in a mixture where O = K, then what happens?

If (I)C + O_2 rarr CO_2 , Q_1 (II) C+1//2 O_2 rarr CO , Q_2 (III) CO + 1//2O_2 rarr CO_2 , Q_3 The heats of reaction Q_1 and Q_2 are -12, -10 respectively. Then Q_3 is

If I_(2)is dissolved in aqueous KI, the intense yellow species , I_(3)^(-) , is formed. The structure of I_(3)^(-) ion is

If I_(1), I_(2)and I_(3) etc. represent the successive ionization potentials of an atoms then the correct order is :

If I and E are ionisation energy and electron affinity of an element in kJ "mole"^(-1) electronegativity is given as

If hydrogen ion concentration in a solution is 1xx10^(-5) moles/litre, calculate the concentration of OH^(-)ion in this solution (K_(w)=10^(-14) "moles"^(2)//"litre"^(2))

If Hydrogen Chloride gas is passed through saturated solution of sodium chloride which precipitate will be obtained ?

If Hunds rule is not obeyed by some elements given below then which atom has maximum magnetic moment

If HNO_(3) changes into N_(2)O, the oxidation number is changed by

If heterolytic and hemolytic cleavage of bond then which type of reaction occurs?

If helium is allowed to expand in vacuum, it liberates heat because

If heat of formation of HI in the given reactions (i) H_(2)(g) + I_(2) to I_(2)(s) to 2HI (ii) H_(2)(g) +I_(2)(g)to 2HI(g) are 26 KJ and -4.5 "mol"^(-1) + respectively , then the heat of sublimation of iodine is

If heat of dissociation of CHCl_(2)COOK+H_(2)O is 0.7 kcal//mole then, DeltaH for the reaction : CHCl_(2)COOH+KOHtoCHCl_(2)COOK+H_(2)O

If [H_3O^+]=3.5xx10^(-8) , So calculate [OH^-] and pH of solution.

If [H^+]=1.67xx10^(-10) M in solution than calculate [OH^-].

If gas having more critical temperature, then its liquification will be …………

If gas has a RMS velocity 5.2 xx 10^4 cms^(-1) , find the average and most probable velocities of the gas

If for two gases of molecular weights M_(A) and M_(B) at temperature T_(A) and T_(B):T_(A)M_(B)=T_(B)M_(A), then which property has the same magnitude for both the gases?

If for an ideal gas, the ratio of pressure and volume is constant and is equal to 1 atm L^(-1) , the molar heat capacity at constant pressure would be

If for a particular reaction, the difference in the heat evolved when the reaction is carried out at constant pressure andthat at constant volume at 27^(@)C is nearly5 kJ mol^(-1) , then the difference in the number of moles of gaseouseactants and products is

If for a chemical reaction Delta C_(p) I stemperature of reactants of this reaction bya certain amount =q_(1) and heat required to increase temperature of products of the same reaction by same amount =q_(2), then:

If for 2A_2B(g) hArr 2A_2(g)+B_2(g), K_p=TOTAL PRESSURE (at equilibrium ) and starting the dissociation from 4 mol of A_2B then:

If the first excitation potential of a hypothetical hydrogen like atom is 15 V, then the third excitation potential of the atom is

If excess of Ca(OH)_2is added to hard water in Clark's method

If excess CO_(2) gas is passed in 0.205 mole Ba(OH)_(2) then give the amount of BaCO_(3)produced.

If ethanol containing EtOD is used as solvent , then deuterium exchange take place in E1cB mechanism . Why ?

If E_(Sn^(2+)//Sn)^(@)=-0.14V, what would be the value of E_(Sn//Sn^(2+))^(@)?

If equilibrium constant for the reaction N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g) at 298 K is 2.54 , the value of equilibrium constant for the reaction (1)/(2) N_(2) + (3)/(2) H_(2) hArr NH_(3) will be ……..

Number of phases present in the following thermodynamic systems are: (a) NH_(4) HS_((s)) hArr NH_(3(g)) + H_(2)S_((g)) (b) CaCO_(3(s)) hArr CaO_((s)) + CO_(2(g)) (c ) N_(2(g)) + 3H_(2(g)) hArr 2NH_(3(g))

If equal weights of oxygen and nitrogen are placed in separate containers of equal volume as the same temperature, which one of the following statements is true? (mol wt. N_(2)=28,O_(2)=32)

If equal volume of 1M KMnO_(4) " and" 1M K_(2)Cr_(2)O_(7) solutions are allowed to oxidise Fe^(2+) " to " Fe^(3+) in acidic medium, then Fe^(2+) will be oxidised :

If equal amounts of ether, acetone and bezene are placed in identical petri dishes, in which order, they will evaporate off and why ?

If E_(n) = -313.6//n_2, if the value of E_1 = -34.84 to which value 'n' corresponds

If electron is added to group 16, 17 which orbit n = 2 and n = 3 shows less electron electron repulsion ? Why?

If electron transitsfrom n=5 to n=2it belongwhichseries.?

Ifelectron is removedfrom an atom then isenergy

If electronis acceleratedby 1.0 xx 10^(4)voltthancalculatekineticenergyfrequencyand wavelength

If electrical conductivity is found to be same in all directions through a solid, the substance is _______ solid and this property is called _______

If electrical conductivity is found to be same in all directions through a solid, the substance is _____ solid and thisproperty is called ________\

If each hydrogen atom in the ground state, 1.0 inole of H atoms are excited by absrobing photons of energy 8.4 eV, 12.09 eV and 15.0 eV of energy, then the number of spectral lines emitted is equal to

If E_(1), E_(2) and E_(3) represent respectively the kinetic energies of an electron, an alpha-particle and a proton each having same de Broglie wavelength, then

IfE_1, E_2 and E_3 represent respectively the kinetic energies of an electron, an alpha particle and a proton respectively each having same deBroblie wavelength then which is incorrect relation?

If E= number of Ione pairs of electrons of Xe B=the number of boding pairs of electrons S=shape of the molecule then, the correct set of E,B and S of XeF_(4)

If distance between two molecules of gases becomes half then which type of changes occurs in London forces ?

If dissociation for reaction PCl_(5) hArr PCl_(3) + Cl_(2) is 20% at 1 atm pressue . Calculate the value of K_(C).

If DeltaH lt T Delta S at 298K temperature, what will be the value of equilibrium constant ?

If DeltaG=0 , then the process is ___

If DeltaG^@ for the reaction given below is 1. kJ, the equilibrium constant for a reaction. 2HI_((g)) harr H_(2(g))+I_(2(g)) at 25^@C is :

If electrical conductivity is found to be same in all directions through a solid, the substance is _ solid and this property is called _

If electrical conductivity is found to be same in all directions through a solid, the substance is _ solid and thisproperty is called ____\