Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

If electrolysis of aqueous solution of CuSO_(4) is carried out using graphite electrode, then what is the pH of solution of electrolytic cell ?

Answer»

pH=14.0
`pH=9.0`
`pH=7.0`
`pH LT 7.0`

Solution :DUE to electrolysis of `CuSO_(4)` solution, `H^(+)` is produced on anode by OXIDATION of water.
Solution of cell is acidic in nature, solution of `CuSO_(4)` is a salt solution of strong ACID and weak base. And pH of acidic solution is ALWAYS less than 7.0.
So `pH lt 7.0`
2.

If electrolysis of aqueous CuSO_(4) solution is carried out using Cu- electrons, the reaction taking place at the anode is

Answer»

`H^(+) + e^(-) rarr H`
`Cu_((AQ))^(2+) + 2e^(-) rArr Cu_(s)`
`SO_(4(aq))^(2-) -2e^(-) rarr SO_(4)`
`Cu_(s) -2e^(-) rarr Cu_((aq)^(2+)`

Solution :THEREACTIONS occuring at the electrodes are as follows :
At cathode , `Cu_((aq))^(2+) + 2e^(-1) rarr Cu_((s))`
copper dissolves into the solution from the anode and is deposited at the cathode.
3.

If E_((Fe^(2+)|Fe))^(o)=-0.441V and E_((Fe^(3+)|Fe^(2+)))^(o)=0.771V, then what is emf for following reaction ? [Fe+2Fe^(3+) to 3Fe^(2+)].

Answer»

1.653
1.212 V
0.111 V
0.330 V

Solution :`Fe^(2+)+2e^(-) to Fe,""E_(1)^(o)=-0.414V`
`Fe^(3+)+e^(-) to Fe^(2+),""E_(2)^(o)=0.771V`
Required REACTION : `Fe+2Fe^(3+) to 3Fe^(2+)`
`=(Fe to Fe^(2+)+2e^(-))`. . .(oxidation)
`+(2Fe^(3+)+2e^(-) to 2Fe^(2+))`. . . (reduction)
`E_(CELL)^(o)=E_(Cathode)^(o)-E_("ANODE")^(o)`
`=0.771-(-0.441)`
`E_(cell)^(o)=1.212V`
4.

If E_(Fe^(2+)//Fe)^(o)=-0.441V and E_(Fe^(3+)//Fe^(2+))^(o)=0.771V, the stardard EMF of the reaction Fe+2Fe^(3+)to3Fe^(2+) will be

Answer»

1.212V
0.111V
0.330V
1.653V

Answer :A
5.

If E_(k) is the average kinetic energy per mole of a gas, then :

Answer»

<P>`pV = ( 3)/( 2) E_(k)`
`P = ( 3)/( 2) V. E_(k)`
`pV = ( 2)/( 3) E_(k)`
`3pV = E_(k)`

Answer :C
6.

If E_(Fe^(2+)//Fe)^(@)=0.441 and E_(Fe^(3+)//Fe^(2+))^(@)=0.771V the standard EMF of the reaction Fe+2Fe^(3+)to3Fe^(2+) will be

Answer»

1.212 V
0.111 V
0.330 V
1.653 V

Solution :The GIVEN CELL is `Fe|Fe^(2+)||Fe^(3+)|Fe^(2+)`
`E_(cell)^(@)=E_(Fe^(3+)//Fe^(2+))^(@)-E_(Fe^(2+)//Fe)^(@)=0.771V-(-0.441V)=1.212V`.
7.

If E_(CIO_(3)^(-)//ClO_(4)^(-))^(@) = -0.36V and E_(ClO_(3)^(-)//ClO_(2)^(-))^(@)= 0.33Vat 300 K . Find the equilibrium constantfor the following reaction . 2ClO_(3)^(-) ClO_(2)^(-)_ClO_(4)^(-)

Answer»

`(0.04)`
`(0.001)`
`(1.0)`
`(4.0)`

Solution : `2ClO_(3)^(-)ClO_(2)^(-)+ClO_(4)^(-)`
the reaction includes to STEPS .
`CIO_(3)^(-) ClO_(4)^(-)["OXIDATION"]`,`ClO_(3)^(-)ClO_(2)^(-) ["Reduction"]`
8.

If edge length in simple cube, bcc and fcc unit cell is a, then the ratio of atomic radius present in them are …….

Answer»

`a/2 : (SQRT3)/2 : (SQRT(2)a)/(2)`
`a/2 : (sqrt3)/4 : a/(2sqrt(2))`
`a/2 : sqrt(3)a : a/(sqrt(2))`
`14 : sqrt(3)a : sqrt(2)a`

ANSWER :B
9.

If E_(cell)=0.118V for the following reaction, then calculate [H^(+)] and pH at 298K temperature. Pt|H_(2)("1 bar")|H^(+)(10^(-6)M)||H^(+)(xM)|H_(2)("1 bar")|Pt

Answer»


ANSWER :`[H^(+)]=10^(-4)M,pH=4.0`
10.

If E_(cell)^(@) of electrochemical cell=1.1 V for possessing following chemical reaction, then what is E_(cell) ? Zn_((S))+Cu_((aq))^(2+)(0.1M) to Zn^(2+)(1M)+Cu_((S))

Answer»

2.12 V
1.8 V
1.07 V
0.84 V

Solution :According to following REACTION, `N=2`.
`E_(CELL)=E_(cell)^(@)-(0.0592)/(n)"log"([Zn^(2+)])/([CU^(2+)])`
`=1.1-(0.0592)/(2)"log"((1.0)/(0.1))`
`=1.1-0.0296log10`
`=1.1-0.296=1.0704V~~1.07V`
11.

If E_(Cd)^(0) = 0.408 V and E_(Ag)^(0) = -799 V, the emf of the cell Cd| Cd^(2+) || Ag^(+) | Ag is

Answer»

`-1.207` V
`+1.207` V
`-0.391 V `
`+0.391 V `

SOLUTION :E CELL = `E_(Cd)^(0) - E_(AG)^(0) = 0.408 - (-0.799) = + 1.207 V`
12.

If EAN of central metal ion X^(2+) in a non-chelating complex is 34 and atomic number of X is 28. Find out the number of monodentate ligands in compelx.

Answer»


SOLUTION :`28-2+2xxx=34 impliesx=4`
13.

If EAN of metal is 36 in [M(CO)_(2)(sigma-C_(5)H_(5))(pi-C_(5)H_(5))] Find the atomic number of metal M

Answer»


SOLUTION :`"EAN" IMPLIES Z-(2)+2xx2+1xx2+3xx2=36`
`Z implies 26`
14.

IfE_(Au^(+)// Au)^(@) is 1.69 V andE_(Au^(3+)//Au)^@ is 1.40 V . Then E_(Au^(+)//Au^(3+))^(@) will be :

Answer»

0.19 V
2.945 V
1.255 V
None of these

Solution :(1) `DeltaG_(1)^0) = 1F (1.69) , (2) DeltaG_2^(0)=-3F(1.40) , (3) DeltaG_3^(0) = -2FE_3^(0)`
(1) `Au^(oplus) + 1E^(-) to Au , DeltaG_1 ^(0) , (2) Au^(+3) + 3E^(-) to Au , DeltaG_2^(0)`
(3) `Au^(+3) + 2e^(-) to Au^(+) , DeltaG_(3)^(0) (3)=(2)-(1)`
`DeltaG_(3)^(0) = DeltaG_2^(0) -DeltaG_1^(0) , 2E_3^(0) = (3 xx 1.40) - 1.89 , E_(Au)^(+0//Au^(+3))^(0) = -1.255`
15.

If EAN of central metal cation M^(2+) in an non-chelating complex is 36 and atomic no. of metal M is 26, then the number of monodentate ligand in this complex are

Answer»

5
4
6
none of these

Answer :C
16.

If E_(1)^(@),E_(2)^(@) and E_(3)^(@) are the standard electrode potential for Fe//Fe^(2+),Fe^(2+),Fe^(2+)//Fe^(3+) and Fe//Fe^(3+) electrodes respectively, derive a relation between E_(1)^(@),E_(2)^(@) and E_(3)^(@).

Answer»

Solution :`FetoFe^(2+)+2e^(-),DeltaG_(1)^(@)=2E_(1)^(@)F` . . . (i)
`Fe^(2+)TOFE^(3+)+E^(-),-DeltaG_(2)^(@)=E_(2)^(@)F` . . (ii)
`Fe to Fe^(3+)+3e^(-),-DeltaG_(3)^(@)=3E_(3)^(@)F` . . . (iii)
Subracting eqn. (i) from eqn. (iii) , we get
`0 to Fe^(3+)-Fe^(2+)+e^(-),-DeltaG_(3)^(@)+DeltaG_(1)^(@)=F(3E_(3)^(@)-2E_(1)^(@))`
or `Fe^(2+) to Fe^(3+)+e^(-),-DeltaG_(3)^(@)+DeltaG_(1)^(@)=(3E_(3)^(@)-2E_(1)^(@))F` . . . (iv)
Comparing eqn. (ii) and (iv), we get
`-DeltaG_(2)^(@)=-DeltaG_(3)^(@)+DeltaG_(1)^(@)`[as eqns. (ii) and (iv) are same] ,brgt i.e., `E_(2)^(@)=F(3E_(3)^(@)-2E_(1)^(@))F` or `E_(2)^(@)=3E_(3)^(@)-2E_(1)^(@)` or `3E_(3)^(@)=E_(2)^(@)+2E_(1)^@`
17.

If each orbital can hold a maximum of 3 electrons, the number of elements in 4th periodic table (long form) is.

Answer»


ANSWER :48
18.

If E_(1)=0.5V corresponds to Cr^(3)+3e^(-)rarr Cr_((s)) and E_(2)=0.41V corresponds to Cr^(3+)+e rarr Cr^(2+) reactions, calculate the emf (E_(3)) of the reaction Cr^(2+)+e rarr Cr^(2+) reactions, calculate the emf (E_(3)) of the reaction Cr^(2+)+2e rarr Cr_((s))

Answer»

Solution :0.655V
HINT : `E_(3)=(3E_(1)-E_(2))/(2)`
19.

If E_(1)=0.5V corresponds to Cr^(3+)+3e^(-) rarr Cr_((s)) " and " E_(2)=0.41V corresponds to Cr^(3+)+e^(-) rarr Cr^(2+) reactions, calculate the emf (E_(3)) of the reaction Cr^(2+)+2e^(-) rarr Cr_((s)).

Answer»

Solution :Given : `E_(1)=0.5V`
`Cr^(3+)+3E^(-) RARR Cr_((s)) "...(1)"`
`E_(2)=0.41V`
`Cr^(3+)+e^(-) rarr Cr^(2+) "...(2)"`
The REQUIRED reaction is,
`Cr^(2+)+2E^(-) rarr Cr_((s))`
Then,
Formula :
`E_(3)=(3E_(1)+E_(2))/2`
Solution :
`""=(3(0.5)+(0.41))/2=(1.5+0.41)/2`
`""=0.955 V`
`E_(3)=0.955V`
20.

If E_(1 )^(0)is standard electrode potential for Fe//Fe^(+2) ,E_(2)^(0) is for Fe^(+2)//Fe^Fe^(+3) and E_(3)^(0)is for Fe// Fe^(+3)then the relation between E_(1)^(0), E_(2)^(0) and E_(3)^(0)will be :

Answer»

`E_(3)^(0) = E_(1) ^(0) + E_(2)^(0)`
`E_(3) ^(0) = (E_(1) ^(0) + E_(2) ^(0))/3`
`E_(3)^(0) = (2E_(1)^(0) +E_(2)^(0))/3 `
`E_(3)^(0) = (E_(1)^(0)+2E_(2)^(0))/3`

Answer :C
21.

If E^(@) value of given ell is 1.1 V at 298 K temperature, then what is the value of equilibrium constant ?

Answer»

`10^(-37)`
`10^(-37)`
`10^(-73)`
`10^(73)`

Solution :`LOGK=(NE)/(0.059)=(2xx1.1)/(0.059)=37.288`
`therefore K=1.65xx10^(37)`.
22.

If E^0 of calomel electrode (C^(o-)|Hg_2Cl_2|Pt|] is 0.27V, its potential whenKCl=0.01 M would be-

Answer»

0.25V
0.26V
0.276V
0.286V

Answer :C
23.

If eis thecharge of an electron in esu m is the mass in grams and v the voltage 'h' is the planck constant in erg sec then the wavelength of the electron in cm is

Answer»

`H//sqrt(Ve)`
`hsqrt(Vme)`
`hsqrt(Ve)`
`hsqrt(2mVe)`

SOLUTION :KINETIC energy of electrons = Potential energy GAINED by each ELECTRON
i.e., 1/2 m `upsilon^2=eV` or `upsilon=sqrt((2eV)/m)`
`therefore lambda=h/(m upsilon)=h/(m((2eV)/m)^(1//2))=h/sqrt(2mVe)`
24.

If E^(@) is positive ,then the DeltaG is……..

Answer»

SOLUTION :NEGATIVE
25.

If (dx)/(dt)=k[H_(3)O^(+)]^(n) and rate becomes 100 times when pH changes form 2 to 1. Hence order of reaction is

Answer»

1
2
3
0

Answer :B
26.

If during a reacton ,in presence of enzyme.heat is evolved or adsorbed ,then what change we can obseve in it?

Answer»

Increases
Decreases
Remains CONSTANT
Can.t judge

Answer :C
27.

If D_(T) and D_(0) are the theoretical and observed vapour densities at a definite temperature and alpha bethe degree of dissociation of a substance. Then, α in the terms of D_(0),D_(T) and n (number of moles of product formed fro 1 mole reactant) is calculated by the formula:-

Answer»

`ALPHA=(D_(0)-D_(T))/((1-n)D_(T))`
`alpha=(D_(T)-D_(0))/((n-1)D_(T))`
`alpha=(D_(T)-D_(0))/((n-1)D_(0))`
`alpha=(D_(0)-D_(T))/((n-1)D_(T))`

Solution :`UNDERSET(1-alpha)(An) HARR underset(nalpha)(nA)`
`(D_(T))/(D_(0))=(1+alpha(n-1))/(1)`
`alpha=(D_(T)-D_(0))/((n-1)D_(0))`.
28.

If doubling the concentration of a reaction A increases the rate 4 times and tripling the concentration of A increases the rate 9 times , the rate is proportional to

Answer»

Concentration of A
Square of concentration of A
Under root of the concentration of A
CUBE of concentration of A

SOLUTION :`2^(2) = 4 , 3^(2) = 9`
29.

If dissociation for reaction, PCl_(5)hArrPCl_(3)+Cl_(2) is 20% at 1 atm, pressure. Calculate 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)])`
`=(0.2xx0.2)/(0.8)=(0.04)/(0.8)=0.05`
30.

If distance between two Pt electrode is 2 cm, cross intercept of 4.0 cm^(2) and resistance is 25Omega, then find out the molar conductivity of 0.5 M solution.

Answer»


Answer :`40" S "cm^(2)MOL^(-1)`
31.

If dispersed phase is gas and dispersion medium is liquid then the type of colloid is…

Answer»

EMULSION 
FOAM 
AEROSOL 
Sol

Solution :Foam
32.

If dispersed phase is a liquid and the dispersion medium is a solid the colloid is known as :

Answer»

a sol
a gel
aerosol
emulsion

Answer :B
33.

If dispersed phase and dispersion medium both are solid, this type of sol is called .........

Answer»

SOL
SOLID sol 
Aerosol
Emulsion 

SOLUTION :Solid sol
34.

If density of some lake water is 1.25 g m L^(-1)and contains 92 g of Na^+ ions per kg of water, calculate the molality of Na^+ ion in the lake.

Answer»

Solution :MOLALITY of `Na^+` IONS in the lake = `(92 //23)/(1 ) = 4`.
35.

If density of a gaseous mixture of dinitrogen tetroxide (N_(2)O_(4)) and nitrogen dioxide (NO)_(2) is 2.5 gm/L at 127^(@)C and 1 atm pressure. [R=0.08 atm lit/mole-k] K_(p) for N_(2)O_(4)(g)hArr2NO_(2) is:

Answer»

`0.90`
0.09
`9.0`
0.009

Solution :`N_(2)O_(4)(G)hArr2NO_(2)(g)`
0.74 atm 0.26atm
`k_(p)=((0.26)^(2))/(0.74)=0.091`
`k_(p)=0.09`
36.

If densities of two gases are in the ratio 1 : 2 and their temperatures are in the ratio 2 : 1, then the ratio of their respective molar mass at certain pressure is:

Answer»

`1:1`
`1:2`
`2:1`
`4:1`

SOLUTION :`PM_(W)=dRT,M_(W)propdT`
`(M_(1))/(M_(2))=(d_(1)T_(1))/(d_(2)T_(2))=(1xx2)/(2xx1)=1/1`
37.

If density of a gaseous mixture of dinitrogen tetroxide (N_(2)O_(4)) and nitrogen dioxide (NO)_(2) is 2.5 gm/L at 127^(@)C and 1 atm pressure. [R=0.08 atm lit/mole-k] Partial pressure of N_(2)O_(4) is:

Answer»

0.62atm
0.47atm
0.74atm
0.26atm

Solution :`N_(2)O_(4)hArr2NO_(2)`
`a_(0)-a_(0)aloha 2a_(0)alpha`
`M_(avg)=(a_(0)xxM.Wr.N_(2)O_(4))/(a_(0)(1+alpha))`
`PM=dRT`
`1xxM_(avg)=2.5xx0.08xx400`
`M_(avg)=(92)/(1+alpha)=80`
`P_(N_(2)O_(4))=(1-alpha)/(1+alpha)xxP_(1)`
`1+alpha=(92)/(80)`
`P_(N_(2)O_(4))=(0.85)/(1.15)xx10.74` atm
`alphah=0.15`
`P_(NO_(2))=1-P_(N_(2)O_(4)`
`1-0.74=0.26` atm
38.

if density of an ideal gas when plotted against pressure exerted, shows the above variation at 273K. Find the molar mass (in gm/mol) the gas?

Answer»

19.4
38.8
77.6
100

Solution :PM=dRT
`d=P((M)/(RT))`
SLOPE `=TAN 60^(@)=(M)/(RT)`
`M=sqrt(3)xx0.0821xx273approx39gm`
39.

If DeltaT_(f) is the depression in freezing point for the electrolyte and DeltaT_(f)^(@) for the non-electrolyte of the same concentration, then Van't Hoff factor (i) is

Answer»

`DeltaT_(F)XX DeltaT_(f)^(@)`
`DeltaT_(f)^(@)// DeltaT_(f)`
`(Delta T_(f)- DeltaT_(f)^(@))/(2)`
`Delta T_(f)// Delta T_(f)^(@)`

ANSWER :D
40.

If DeltaH_(f(C_(2)H_(6)))^(0)(g) = -85 KJH mol^(-1) , DeltaH_(f(C_(3)H_(8)))^(0) (g) = -104 KJ mol^(-1), DeltaH^(0)for C (s) rarr C(g) is 718 KJ mol^(-1) and heat of formation of H-atom is 218 KJmol^(-1) then :

Answer»

`DeltaH_(C-C) = 345` KJ
`DeltaH_(C-H) = 414` KJ
`DeltaH_(H-H)=436 KJ`
`DeltaH_(H-H) = 436` KJ

Solution :`2C + 3H_(2) rarr C_(2)H_(6)`
Also, `DeltaH_(f(C_(2)H_(6)))^(0)(G) = 2xx 718 + 3xx436 - a - 6b"" (DeltaH_(C-C) = a, DeltaH_(C-H) = B)`
`a+ 6b = 2829"""…."(i)`
`3C + 4H_(2) rarrC_(2)H_(8)`
`DeltaH_(f(C_(3)H_(8)))^(0) (g) = 3XX 718 + 4 xx 436 - 2a - 8b`
`2a + 8b = 4002"""....."(ii)`
`a = 345"&" b=414 KJ.`
41.

If DeltaH_("vaporisation") of substance X (l) (molar mass : 30 g/mol) is 300 J/g at it's boiling point 300 K, then molar entropy change for revesible condensation process is

Answer»

30 J/mol K
`-300` J/mol K
`-30` J/mol K
None of these

Answer :C
42.

If Delta_(t) represents CFSE in a tetrahedral crystal field t_(2) ….. The bari centre and e lies …… the bari centr.

Answer»

SOLUTION :`0.4 Delta_(t)` above, `0.6 Delta_(t)` below
43.

If DeltaH_f^@" for " H_2O and H_2O_2 " are " -280 and -188 kJ mol^(-1), the enthalpy change for the reaction, 2 H_2O_2 (l) to 2H_2O (l) + O_2(g) is :

Answer»

`-196 KJ mol^(-1)`
`146 kJ mol^(-1)`
`-494 kJ mol^(-1)`
`-98 kJ mol^(-1)`

Answer :A
44.

If DeltaH is the enthalpy change and DeltaE the change in internal energy accompanying a gaseous reaction then

Answer»

`DeltaH` is always less than `DeltaE`
`DeltaH` is always greater than `DeltaE`
`DeltaH` is less than `DeltaE` if the number of gaseous PRODUCTS is greater than the number of MOLES of gaseous REACTANTS.
`DeltaH` is less than `DeltaE` if the number of moles of gaseous products is less than the number of moles of gaseous reactants.

ANSWER :D
45.

If DeltaH is the change in enthalpy and DeltaE the change in internal energy accompanying a gaseous reaction

Answer»

`DeltaH` is ALWAYS GREATER than `DeltaE`
`DeltaH LT DeltaE` only if the number of moles of the PRODUCTS is greater than the number of the reactants
`DeltaH` is always LESS than `DeltaE`
`DeltaH lt DeltaE` only if the number of moles of the products is less than number of moles of the reactants

Answer :D
46.

If DeltaH is the change in enthalpy and DeltaE the change in internal energy for a gaseous reaction then

Answer»

`DELTAH ` is ALWAYS GREATER than `DeltaE`
`DeltaH lt DeltaE` only if the NUMBER of moles of the products is greater than the number of the reactants
`DeltaH ` is always LESS than `DeltaE`
`DeltaH lt DeltaE` only if the number of moles of the products is less than the number of moles of the reactants

Answer :D
47.

If DeltaH is the change in enthylpy and DeltaU, the change in internal energy accompanying a gaseous reactant then

Answer»

`DeltaH` is always greater than `DELTAE`
`DELTA H LT DeltH` only if the NUMBER of moles of the products is greater than the number of moles of the reactants
`DeltaH` is always less than `DeltaE`
`Delta H lt Delta E` only if the number of moles of products is less than the number of moles of the reactants

Answer :D
48.

If DeltaG^(@)[HI(g)=-1.7kJ], the equilibrium constant for the reaction 2HI(g)hArr H_(2)(g)+I_(2)(g) at 25^(@)C is

Answer»

24
2
3.6
0.5

Answer :C
49.

If DeltaG^@ (HI, g) is 1.7 kJ, what is the equilibrium constant at 20^@C for 2HI(g) hArr H_2(g)+ I_2(g)

Answer»

24
3.9
2
0.5

Answer :B
50.

If DeltaG is negative, the reaction will be

Answer»

At equilibrium
Not possible
Both (a) and (B)
Possible

Solution :For a FEASIBLE REACTION `DELTAG` should be NEGATIVE.