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 the solubility product of CuS is 6xx10^(-16), calculate the maximum molarity of CuS in aqueous solution.

Answer»

Solution :Maximum molarity of CUS in aqueous solution = Solubility of Cus in mol `L^(-1)`
If S is the solubility of CuS in mol `L^(-1)`, then
`CuShArrunderset("S")(CU)^(2+)+underset(S)(S)^(2-),K_(SP)=[Cu^(2+)][S^(2-)]=SxxS=S^(2)`
`therefore""S^(2)=6XX10^(-6)"or"S=sqrt(6xx10^(-16))=2.45xx10^(-8)" mol L"^(-1)`
2.

If the solubility product of lead iodide is (PbI_2) is 3.2 times 10^-8. Then its solubility in moles/litre will be……..

Answer»

`2 times 10^-3 M`
`4 times 10^-4 M`
`1.6 times 10^-5`
`1.8 times 10^-5 M`

SOLUTION :`K_(SP)=4s^3`
`4s^3=3.2 times 10^-8 IMPLIES s=2 times 10^-3 M`
3.

If the solubility product of lead iodide is 3.2 times 10^-8, its solubility will be……..

Answer»

`2 times 10^-3 M`
`4 times 10^-4 M`
`1.6 times 10^-5 M`
`1.8 times 10^-5 M`

Solution :`Pbl_s(s) leftrightarrow Pb^(2+) (AQ)+21^(-) (aq)`
`K_(SP)=(s) (2s)^2`
`3. 2 times 10^-8=4s^3`
`s=((3.2 times 10^-8)/4)^(1//3)=(8 times 10^-9)^(1//3)=2 times 10^-3 M`
4.

If the solubility product of CuS is 6xx10^(-15), calculate the maximum molarity of CuS in aqueous solution.

Answer»

Solution :SOLUBILITY product of CuS, `K_(SP)=6xx10^(-15)`
Let us be the solubility of CuS in mol `L^(-1)`
`CuS harr underset(S)(Cu^(2+))+underset(S)(S^(2+))`
Now,`K_(SP)=[Cu^(2+)][S^(2-)]`
`= S XX S`
`= S^(2)`
Then we have,
If `S^(2)=6xx10^(-15)`
`S = sqrt(6xx10^(-15))`
thus,`S=sqrt(60XX10^(-16))`
`= sqrt(60)xx10^(-8)`
`S=2.45xx10^(-8)M`.
5.

If the solubility product of CuS is 6 xx 10^(-16) , calculate the maximum molarity of CuS in aqueoussolution.

Answer»

SOLUTION :MAXIMUM molarity of CuS in aqueous solution = Solubility of CuS in mol `L^(-1)`
If S is the solubility of CuS in mol `L^(-1)`, then
`CuS IFF Cu^(2+)(s) + S^(2-)(s)`
` therefore S^2=6 xx 10^(-16) " or" S = sqrt(6 xx 10^(-16))`
Hence, solubility = `2.45 xx 10^(-8 )"mo "L^(-1)`
6.

If the solubility product of CuS is 6 xx 10^(-16), calculate the maximum molarity of CuS in aqueous solution .

Answer»

Solution :`K_(sp)` of CuS = `6 XX 10^(-16)`
If S is the solubility , then
`CuS to Cu^(2+) + S^(2-)`
`[Cu^(2+)] = S , [S^(2-)]= S`
`K_(sp) = [Cu^(2+)] [S^(2-)]`
`= S xx S= S^(2)`
Solubility S = `sqrt(K_(sp)) = sqrt(6 xx 10^(-6))`
`= 2.45 xx 10^(-8) M`
Highest molarity = `2.45 xx 10^(-8) M`
7.

If the solubility product of AgBrO_(3) and Ag_(2)SO_(4) are 5.5 xx 10^(-5) and 2 xx 10^(-5) respectively, the relationship between the solubilities of these can be correctly represented as

Answer»

`S_(AgBrO_(3)) gt S_(Ag_(2)SO_(4))`
`S_(AgBrO_(3)) lt S_(Ag_(2)SO_(4))`
`S_(AgBrO_(3)) = S_(Ag_(2)SO_(4))`
`S_(AgBrO_(3)) ~~ S_(Ag_(2)SO_(4))`

Solution :`{:(Ag_(2)SO_(4), RARR, 2Ag^(+) + ,SO_(4)^(--)),(,,4S^(2), S):}`
`K_(sp) = 4S^(3), K_(sp) = 2 xx 10^(-5)`
`S = sqrt((2 xx 10^(-5))/(4)) = 0.017 m//l = 1.7 xx 10^(-2)`
`{:(AgBrO_(3), rarr, Ag^(+) + ,BrO_(3)^(-)),(,,S,S):}`
`K_(sp) = S^(2), K_(sp) = 5.5 xx 10^(-5)`
`S = sqrt(5.5 xx 10^(-5)) = 7.4 xx 10^(-3) m//l`.
8.

IF the solubility product K_(sp) of a sparingly soluble salt MX_(2) at 25^(@)C is 1.0 xx 10^(-11), the solubility of the salt in mole "litre"^(-1) at this temperature will be

Answer»

`2.46 xx 10^(14)`
`1.36 xx 10^(-4)`
`2.60 xx 10^(-7)`
`1.20 xx 10^(-10)`

SOLUTION :`{:(MX_(2),RARR,M^(+)+,2X_(2)^(-),,K_(SP) = 4S^(3)),(,,(S),(2S)^(2),):}`
`S = 3sqrt((K_(sp))/(4)) = 3sqrt((1 xx 10^(-11))/(4)) = 1.35 xx 10^(-4)`
9.

If the solubility product of AgBrO_3 and Ag_2 SO_4 are 5.5 xx 10^(-5) and 2 xx 10^(-5) respectively, the relationship between the solubilities of these have correctly represented as

Answer»

A) `s AgBrO_(3) -= Ag_(2) SO_(4)`
B)`sAg BrO_(3) lt s Ag_(2) SO_(4)`
C)`s AgBrO_(3) =s Ag_(2) SO_(4)`
4)`s AG BrO_(3) gt s Ag_(2) SO_(4)`

ANSWER :B
10.

if the solubility of product of lead iodide(PbI_2) is 3.2xx10^(-8) its solubility will be:

Answer»

`2XX10^(-3)` M
`1XX10^(-4)` M
`1.6xx 10^(-5)` M
`1.8xx10^(-5)` M

Answer :A
11.

If the solubility of Pbbr_(2) is S g-mole per litre, its solubility product, considering it to be 80% ionized, is

Answer»

`2.048 S^(2)`
`20.48 S^(3)`
`2.048 S^(3)`
`2.048 S^(4)`

Solution :`PbBr_(2) hArr Pb^(2+) + 2Br^(-)`
`S(S xx 80)/(100) (2S xx 80)/(100)`
[`because PbBr_(2)` ionises to 80%]
`K_(SP) = [(S xx 80)/(100)][(2S xx 80)/(100)]^(2)`
`= 0.8 S xx 2.56 S^(2) = 2.048 S^(3)`
12.

If the solubility of Pb3 (PO_4)_2 is mol per litre, then the solubility product of Pb_3(PO_4)_2 will be :

Answer»

`6s^2`
`6s^5`
`s^5`
`108s^5`

ANSWER :D
13.

If the solubility of Mg(OH)_2 in water is S mol L^-1 then its K_sp will be

Answer»

`S^3`
`4 S^3`
`27 S^3`
`8 S^3`

ANSWER :B
14.

If the solubility of lithium sodium hexafluoro aluminate Li_(3)Na_(3)(AlF_(6))_(2) is x mol L^(-1), then its solubility product is equal to :

Answer»

`18X^(3)`
`12x^(3)`
`x^(8)`
`2916 x^(8)`

Answer :D
15.

If the solubility of lithium sodium hexafluro-aluminate, Li_3Na_3(AlF_6)_2 is 'a' mol/litre, its solubility product is equal to:

Answer»

`a^2`
`12a^2`
`18a^3`
`2916a^8`

ANSWER :D
16.

If the solubility of Ca(OH)_2 is sqrt3, the solubility product of Ca(OH)_2 is :

Answer»

3
27
`SQRT3`
`12sqrt3`

ANSWER :D
17.

If the solubility of an aqueous solution of Mg(OH)_(2) be Xmoll t^(-1) than k_(sp) of Mg(OH)_(2)is:

Answer»

`4X^(3)`
`108X^(5)`
`27X^(4)`
9X

Solution :`Mg(OH)_(2) to underset(s)(Mg^(2+)) + underset(2S)2OH^(-)`
`K_(sp)=[Mg^(2+)][OH^(-)] = Sxx(2S)^(2) = 4S^(3 = 4X^(3)`
18.

If the solubility of a sparingly soluble saltof the type BA_(2) (giving three ions on dissociation of a molecule) is x moles per litre, then its solubility product is given by

Answer»

`x^(2)`
`2X^(3)`
`4 x^(2)`
`4 x^(3)`

Solution :By formula `BA_(2) RARR B^(+) + 2A^(-)`
`K_(SP) = 4x^(3)`
19.

If the solubility of a sparingly soluble salt of the type BA_2 (giving three ions on dissociation of a molecule) is x mole per litre, Then its solubility product is given by :

Answer»

`x^2`
`2x^2`
`4x^2`
`4x^3`

ANSWER :D
20.

If the shortest wavelength of H atom in Layman series is x, then the longest wavelength in Balmer series of He^(+) is

Answer»

`(36x)/5`
`(5x)/9`
`(9x)/5`
`x/5`

SOLUTION :For the SHORTEST wavelength of Lyman series in H-atom.
`1/(lamda)=R(1/(1^(2))-1/(prop^(2)))=R` or `lamda=1/R=x`………..(i)
For largest wavelength of Balmer series.
`1/(lamda.)=Rxx2^(2)xx(1/4-1/9)=4Rxx5/36`
or `1/(lamda.)=(5R)/9`…………(ii)
or `lamda.=9/(5R)=(9x)/5""( :. 1/R=x)`
21.

If the shortest wave length of Lyman series of H atom is x, then the wave length of the first line of Balmer series of H atom will be-

Answer»

`9x//5`
`36x//5`
`5x//9`
`5x//36`

ANSWER :B
22.

If the series limit of wavelength of the Lyman series for the hydrogen atom is 912 overset@A, then the series limit of wavelength for the Balmer series of the hydrogen atom is:

Answer»

912 `OVERSET@A`
`912xx2 overset@A`
`912xx4 overset@A`
`912/2overset@A`

ANSWER :C
23.

If the shortest wavelength of H-atom in Lyman series is x, then longest wavelenght in Balmer series of He^(2+) is :

Answer»

`(X)/(4)`
`(5x)/(9)`
`(6x)/(5)`
`(9x)/(5)`

ANSWER :D
24.

If the % -s character in one Sb -H bond in SbH_(3) is 1.0 % . What is % p-character is the orbital occupied by its lone pair.

Answer»

99
97
90
none

Answer :A
25.

If the rms speed of the NH_3molecule is found to be 0.51 km/s, what is the temperature?

Answer»

SOLUTION :`-95^@C`
26.

If the root mean square speed of helium is 4.75 m s^(-1) at 25^(@)C, then its speed will become 9.50 ms^(-1) at

Answer»

`100^(@)C`
`323^(@)C`
`919^(@)C`
`1192^(@)C`

SOLUTION :r.m.s. speed `prop sqrt( T )`
`( 4.75 )/( 9.50) = sqrt(( 298)/( T))`
or `( 4.75^(2))/(9.50) = ( 298)/( T )`
or `T =1192 K`
or `T = 1192 - 273 = 919^(@)C`
27.

If the relation between time of decay (t) and half life period (t_(1//2)) is (t = 4 t_(1//2)), the relation between r and mean life (T) is:

Answer»

`(In 2)/(T^(2))`
`27^(4)` In 2
4 T In 2
2T In 2

Answer :c
28.

If the reduction potential is more, then

Answer»

it is EASILY oxidised
It is easily reduced
It ACTS as oxidising agent
It has REDOX nature

Answer :C
29.

if the reaction is reversible all is at equilibrium (DeltaS_universe = 0), then the entropy of the system

Answer»

will CHANGE abruptly
is greater than 1
will REMAIN constant
is equal to 0

Answer :C
30.

If the reaction Fe_2O_3(s)+3CO(g)

Answer»


ANSWER :In OPEN VESSEL
31.

If the reaction between A and B to give C shows first order kinetics in A and Second order in B, the rate equation can be writen as :

Answer»

`rate=k[A][B]^(1/2)`
`rate=k[A]^(1/2)[B]
`rate=k[A][B]^2`
`rate=k[A]^2[B]`.

ANSWER :C
32.

If the ratio of the rates of diffusion of two gases A and B is 4 : 1, then what is the ratio of densitiesof B and A ?

Answer»

`16 : 1 `
`1 : 16 `
`2 : 1 `
`1 : 2 `

SOLUTION :`r_1/r_2=sqrt(d_2/d_1)`
`4/1=sqrt(d_2/d_1)`
`16/1=d_2/d_1`
33.

If the ratio of PV_(m) & RT for a real gas is (x)/(24) at a temp where ((delP)/(delV_(m))) =0. The find value of 10x.

Answer»


SOLUTION :N//A
34.

If the rate of reaction increases by two times with every 10^@C rise in temperature, then if we raisethe temperature by 40^@C, the new rate of the reaction will be :-

Answer»

4 TIMES
8 times
32 times
16 times

SOLUTION :`r_2/r_1=(2)^4=16`
35.

If the rate of the reaction is equal to the rate constant , the order of the reaction is

Answer»

3
0
1
2

Solution :For ZERO ORDER REACTION R = K .
36.

If therate ofreactionincreases by a factorof 2.36 , when thetemperatureis raised from300 K to 313 K .Whatis theenergyactivation? R =8.314 JK^(-1) mol^(-1)

Answer»

Solution :`E_(a) =67 .6 KJ "MOL"^(-1)`
37.

If the rate of reaction increases by 27 times, when temperature is increased by 30 K, then temperature coefficient of the reaction is___________________

Answer»


Solution :`x=((T_(2)-T_(1))/10)=30/10impliesx=3,(r_(2))/(r_(1))=(K_(2))/(K_(1))=mu^(x)impliesmu^(3)=27,mu^(3)=3^(3),mu=3`
38.

If the rate of reaction between A and B is given by rate =k[A][B]^(2), then the reaction is

Answer»

FIRST order in A
second order in B
third order overall
none of the above

Answer :A::B::C
39.

If the rate of reaction between A and B is. given by,rate =K[A][B]^n, then the reaction is :

Answer»

FIRST ORDER in A
`NTH `order in B
Overall order is (1+n)
All are correct

Answer :D
40.

If the rate of reaction, 2SO_2(g)+O_2(g)overset(Pt)to2SO_3(g) is given by : Rate=K([SO_2])/([SO_3]^(1//2)) which statement are correct :

Answer»

The OVERALL order of reaction is `-1//2`
The overall order of reaction is `+1//2`
The reaction SLOWS down as the PRODUCT `SO_3` is build up
The rate of reaction does not depend upon concentration of `SO_3` formed

Solution :Over all order of RXN =`(1-1/2)=+1/2` as `SO_3` for Rate of Rxn slow down.
41.

If the rate of gaseous reaction is independent of pressure, the order of raction is

Answer»

0
1
2
3

Answer :A
42.

If the rate of a reaction is 5 at 10^(@)Cthen onincreasing the temperature to 30^(@)C , new rate is

Answer»

20
10
50
40

Solution :For every `10^(@)` RISE of temperature rate CONSTANT doubles .
For `20^(@)` rise of temperature , rate constant becomes 4 TIMES ,
i.e., `k_(2) = 4k_(1) = 4 xx 5 = 20.`
43.

If the rate of formation of NH_3 for the reaction N_2+3H_2rarr2NH_3 is 2xx10^-4 Msec^-1, the rate of disappearance of hydrogen is

Answer»

`1xx10^-4Msec^-1`
`2xx10^-4Msec^-1`
`3xx10^-4Msec^-1`
`6xx10^-4Msec^-1`

ANSWER :C
44.

What would be the activation energy of a reaction when the temperature is increased from 27^(@)C to 37^(@)C ?

Answer»

SOLUTION :`ln. (k_(2))/(k_(1))=(E_(a))/(R )[(T_(2)-T_(1))/(T_(1)T_(2))]`
`ln 2 = (E_(a))/(R )[(10)/(300xx310)]`
`E_(a)=9300` R ln 2
`= 53.4 "KJ mol"^(-1)`
45.

If the rate law for a reaction is A+B rarr is C(d[A])/(dt)xx(1)/(2)=k[A]^(n)[B]^(m) then the order of a reaction is __________

Answer»

N
m
`n + m`
`m - n`

ANSWER :C
46.

If the rate expresson for a chemical reaction is Rate= k [A] [B]^n then

Answer»

the ORDER of reaction is 1
the order of reaction reaction is N
the order of reaction is (1 + n)
k is INDEPENDENT of temearature

Solution :Order of reaction = (m + n) = 1 + n
`(because m = 1)`
47.

If the rate for the chemical reaction is expresssed at Rate =K[A][B]" then

Answer»

one
n
`1+n`
`1-n`

ANSWER :C
48.

If the rate constant of a first order reaction at a certain temperature is 1.5xx10^(-1)s^(-1) and t_(1) and t_(2) are the respective times for 50% and 75% completion of the reaction, determine the ratio of t_(2)" to "t_(1).

Answer»


Solution :`k=(2.303)/(k)LOG""(a)/(a-x)`
For `3//4` of the REACTION to OCCUR, `t=t_(3//4),(a-x)=a-3a//4=a//4:.t_(3//4)=(2.303)/(k)log4`
For HALF of a reaction to occur, `t=t_(1//2),(a-x)=a-a//2=a//2.:.t_(1//2)=(2.303)/(k)log""(a)/(a//2)=(2.303)/(k)LOG2`
Hence, `(t_(3//4))/(t_(1//4))=(log4)/(log2)=(0.6021)/(0.3010)=2.`
49.

If the rate constant of a reaction is k = 3 xx 10^(-4) s^(-1), then identify the order of the reaction.

Answer»

Solution :On the BASIS of UNIT of rate constant `(s^(-1))`, the ORDER of reaction is FIRST order.
50.

If the rate constant for a first order reactions K ,the time (t) required for the completion of 99% of the reaction is given by :

Answer»

t=2.303 /k
t=0.693/k
t=6.909 /K
t=4.606/k

Solution :When 99% REACTION is completed,
`[R]_(t)=((100-99)/(100))[R]_(0)`
`[R]_(t)=((100-99)/(100))[R]_(0)`
`t=(2.303)/(K)` log `([R]_(o))/([R]_(t))`
`therefore t=(2xx303)/(K)` log` ([R]_(o))/((100-99)/(100))[R]_(o)`
`t=(2.303)/(K)` log `100=(2.303)/(K)`log`10^(2)`
`t=(2.303)/(K).2"log"10`
`t=(2.303xx2)/(K)[therefore log 10=1]`
`t=(4.606)/(K)`