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.

In the isolation of fluorine a number of difficulties were encountered which statement is correct

Answer»

Fluorine reacts with moist GLASS vessels
Fluorine has great AFFINITY for hydrogen
Electrolysis of aqueous HF gives ozonised oxygen
The POTENTIAL required for the discharge of the fluoride IONS is the lowest

Answer :D
2.

In the isolation of fluorine, a number of different of difficulties were encountered. Which statement is correct

Answer»

The potential required for the discharge of the FLUORIDE ions is the LOWEST
Fluorine reacts with most glass vessels
fluorine has great affinity for hydrogen
Electrolysis of AQUEOUS HF gives ozonised oxygen

ANSWER :A
3.

In the following groups (1) -OA c (2) -OM e (3) -OSO_(2)Me (4) -OSO_(2)CF_(3) the order of leaving group ability is

Answer»

`1gt2gt3gt4`
`4gt3gt1gt2`
`3gt2gt1gt4`
`2gt3gt4gt1`

ANSWER :B
4.

In the isoelectronic speciesthe ionic radii (Å) of N^(3-), O^(2-) and F^(-) are respectively given by

Answer»

1, 36, 1.40, 1.71
1.36, 1.71, 1.40
1.71, 1.40, 1.36
1.71, 1.36, 1.40

Answer :C
5.

In the isoelectronic series of metal carbonyl, the CO bond strength is expected to increase in the order:

Answer»

`[MN(CO)_(6)]^(+) lt [Cr(CN)_(6)] lt [V(CO)_(6)]^(-)`
`[V(CO)_(6)]^(-) lt [Cr(CO)_(6)] lt [Mn(CO)_(6)]^(+)`
`[V(CO)_(6)]^(-) lt [Mn(CO)_(6)]^(+) lt [Cr(CO)_(6)]`
`[Cr(CO)_(6)] lt [Mn(CO)_(6)]^(+) lt [V(CO)_(6)]^(-)`

SOLUTION :CO bond strength is reciprocal to the extent of back DONATION involved in synergic bonding i.e., `M hArr CO`
6.

In the following groups,

Answer»

I`gt `II` gt `III `gt`IV
IV` gt` III` gt` I` gt` II
III` gt `II` gt` I `gt` IV
II` gt` III` gt` IV` gt` I

Solution :F
7.

In the isoelectric species the ionic radii (Å) of N^(3-) O^(2-) and F^(-) are respectively,

Answer»

`1.36, 1.40, 1.71`
`1.36, 1.71, 1.40`
`1.71, 1.40, 1.36`
`1.71, 1.36, .40`

Solution :IONIC RADII DECREAE in the isoelectronic series as `N^(3-)gtO^(2-)gtF^(-)`
8.

In the following gaseous phase first order reaction A_((g))to2B_((g))+C_((g)) Initial pressure was found to be 400mm and it changed to 1000mm after 20 minutes. Calculate the rate.

Answer»

Solution :`{:(A_((g)),,to,,2B_((g)),,+,,C_((g))),(P_(i),,,,0,,,,0),((P_(1)-X),,,,2x,,,,x):}`
`P_(t)=P_(i)-x+2x+x=(P_(i)+2x)`
`:.x=(P_(t)-P_(i))/(2)`
`:.(a-x)=P_(i)-((P_(t)-P_(i)))/(2)=(3P_(i)-P_(t))/(2)`
`=(3xx400-1000)/(2)=100mm`
`K=(2.303)/(t)LOG((a)/(a-x))`
`=(2.303)/(20)log.(400)/(100)=0.0693min^(-1)`
9.

In the ionic equation for the reaction : IO_(3)^(-)+6H^(+)+ae^(-)toI^(-)+3H_(2)Othe value of a is :

Answer»

2
4
6
10

Answer :C
10.

In the following gaseous phase first order reaction A(g) rarr 2B(g)+C(g) initial pressure was found to be 400 mmof Hgand it changed to 1000 mm of Hg after 20min. Then

Answer»

half life for A is 10 MIN
rate constant is 0.0693 `"min"^(-1)`
partial PRESSURE of C at 30 min is 350 mm of Hg
total pressure after 30 min is 1100 mm of Hg

Answer :A::B::C::D
11.

In the iodometric estimation in laboratory, which process is involved

Answer»

`Cr_(2)O_(7)^(2-)+H^(+)+I^(-)to2Cr^(3)+I_(2),I_(2)+S_(2)O_(3)^(2-)toS_(4)O_(6)^(2-)+I^(-)`
`MnO_(4)^(-)+H^(+)+I^(-)toMnO_(2)+I_(2)`
`I_(2)+S_(2)O_(3)^(2-)toS_(4)O_(6)^(2-)+I^(-)`
`MnO_(4)^(-)+OH^(-)+I^(-)toMnO_(2)+I_(2)`
`I_(2)+S_(2)O_(3)^(2-)toS_(4)O_(6)^(2-)+I^(-)`
`Cr_(2)O_(7)^(2-)+OH^(-)+I^(-)to2Cr^(3+)+I_(2)`
`I_(2)+S_(2)O_(3)^(2-)toS_(4)O_(6)^(2-)+I^(-)`

ANSWER :B
12.

In the following first order competing reactions: A + ReagentrarrProduct B + Reagent rarrProduct The ratio of K_1//K_2 if only 50% of B will have been reacted'when 94% of A has been reacted is:

Answer»

4.06
0.246
2.06
0.06

Answer :A
13.

In the ionic equation - BiO_(3)^(-) + 6H^(+) + Xe^(-) → Bi^(3+) + 3H_(2)O the values of x is

Answer»

6
2
4
3

Solution :`BiO_(3)^(-) + 6H^(+) + xe^(-) RIGHTARROW Bi^(3+) + 3H_(2)O`
By electroneutrality principle,
`-1 + 6 + X(-1) = 3 + 0`
or `+5 + x(-1) = 3 Rightarrow x = 2`
14.

In the following figure, when the two stopcocks are opened, the total pressure inside the flask will be

Answer»

1.41 atm
2.41 atm
3.41 atm
1.12 atm

Answer :A
15.

In the ideal gas equation, the gas constant R has the units :

Answer»

litre `MOL^(-1)`
erg `mol^(-1)`
litre atm `mol^(-1)` `K^(-1)`
ml atm `mol^(-1) K`

Answer :C
16.

In the following first order competing reactions: A + ReagentrarrProduct B + Reagent rarrProduct The ratio ofK_1/ K_2 if only 50% of B will have been reacted.when 94% of A has been reacted is:

Answer»

4.06
0.246
2.06
0.06

Answer :A
17.

In the hydrolytic equilibrium A^- + H_2O hArr HA + OH^-K_a = 1.0 xx 10^(-5) . The degree of hysrolysis of 0.001 M solution of the salt is :

Answer»

`10^(-3)`
`10^(-4)`
`10^(-5)`
`10^(-6)`

ANSWER :A
18.

In the following fields, how adsorption is applied? (i) Medicine (ii) Metallurgy (iii) Mordant & Dyes (iv) indicators

Answer»

Solution : (i) Medicine: - DRUGS cure diseases by adsorption on body tissues.
(ii) Metallurgy:- Sulphide ores are concentrated by a process called froth floation in which lighter ore particles are adsorbed by PINE oil.
(iii) Mordants and Dyes:- Most of the dyes are adsorbed on the surface of the fabric. Mordants are the substances USED for fixing dyes onto the fabric.
(iv) In the precipitation titrations, the end point is indicated by an external indicator which changes its colour after GETTING absorbed on PRECIPITATE. It is used to indicate the end point of filtration.
19.

In the hydrolytic equilibrium , A^(-) + H_(2) O hArr HA + OH^(-) K_a = 1 .0 xx 10^(-5) . The degree of hydrolysis of 0.001 M solution of the salt is

Answer»

`10^(-6)`
`10^(-4)`
`10^(-5)`
`10^(-3)`

ANSWER :D
20.

In the following equilibrium N_(2)O_(4)(g) rarr 2NO_(2)(g)When 5 moles of each is taken and the temperature is kept at 298 k, the total pressure was found to be 20 barGiven : DeltaG^(@)_(f)(N_(2)O_(4) = 100 KJ)DeltaG^(@)_(f)(NO_(2)) = 50 KJFind DeltaG^(@) of the reaction at 298 K

Answer»

<P>`-4.68 KJ`
`-6.04 KJ`
`-5.705 KJ`
`0.4 KJ`

Solution :REACTION quotient = `p[NO_(2)]^(2)/p[N_(2)O_(4)] = 100/10 = 10`
`DeltaG^(@) = 2DeltaG^(@)_(f)(NO_(2))-DeltaG^(@)_(f)(N_(2)O_(4)) = 2 xx 50 - 100 = 0`
`DeltaG = DeltaG^(@) - 2.303RT log_(10)Q_(p) = 0 - 2.303 xx 8.314 xx 298 log_(10)10 = -5705.8 J = -5.705 KJ`
21.

In the hydrolysis of an organic chloride in presence of large excess of water,RCl+H_2OrarrROH+HCl

Answer»

MOLECULARITY and order of REACTION both are 2
molecularity is 2 but order of reaction is 1
molecularity is 1 but order of reaction is 2
molecularity is 1 and order of reaction is also 1.

Solution :SINCE water is present in excess, the reaction is pseudo unimolecular.
22.

In the following fields, how adsorption is applied? (i) Medicine(ii) Metallurgy (iii) Mordant & Dyes (iv) indicators

Answer»

Solution :(i) Medicine :- Drugs cure diseases by adsorption on BODY tissues.
(II) Metallurgy:- Sulphide ores are concentrated by a process called froth floation in which lighter ORE particles are adsorbed by pine oil.
(iii) MORDANT and Dyes:- Most of the dyes are adsorbed on the surface of the fabric. Mordants are the sustances used for fixing dyes onto the fabric.
(iv) In the precipitation titrations, the end point is indicated by an external indicator which changes its colour after GETTING absorbed on precipitate. It is used to indicate the end point of filtration.
23.

In the hydrogenation of the following reaction the state of carbon changes from : C_(2)H_(2)toC_(2)H_(4)toC_(2)H_(6)

Answer»

`SP-sp^(2)-sp^(3)`
`sp^(3)-sp^(2)-sp`
`sp^(2)-sp-sp^(3)`
`sp^(3)-sp-sp^(2)`

Solution :`C_(2)H_(2)(sp)toC_(2)H_(4)(sp^(2))toC_(2)H_(6)(sp^(3))`
24.

In the following equilibrium, N_2O_4(g)to2NO_2(g) when 5 moles of each is taken and the temperature is keptat 298K, the total pressure was found to be 20 bar. Given : /_\G_f^0(N_2O_4)=100kJ,/_\G_f^0(NO_2)=50kJ Find the direction of the reaction.

Answer»

SOLUTION :`prop=SQRT((K_a)/(C))=sqrt((1.8xx10^(-5))/(0.001))=0.1341` i.e., 13.41%
25.

In the following equilibrium , N_2O_4(g) hArr 2NO_2(g) When 5 moles of each are taken , the temperature is kept at 298 K the total pressure was found to be 20 bar . Given that DeltaG_f^@(N_2O_4)=100 KJ DeltaG_f^@(NO_2)=50 kJ (i) Find DeltaG of the reaction. (ii) in which direction the equilibrium of reactionwill shift ?

Answer»


Answer :(i) 56.0304 Lt ATM (ii) therefore, reaction will shift TOWARDS BACKWARD DIRECTION
26.

In thehydroboration- oxidationreactionof propanewithdibrane , H_(2)O_(2)and NaOH, theorganiccompoundformedis :

Answer»

`CH_(3)CH_(2)OH`
`CH_(3)CHOHCH_(3)`
`CH_(3)CH_(2)CH_(2)OH`
`(CH_(3))_(3)COH`

Solution :`CH_(3)CH = CH_(2)overset (B_(2)H_(6)) underset (H_(2)O_(2),NaOH) toCH_(3)CH_(2)CH_(2)OH`
27.

In the following equilibrium, N_2O_4(g)to2NO_2(g) when 5 moles of each is taken and the temperature is keptat 298K, the total pressure was found to be 20 bar. Given : /_\G_f^0(N_2O_4)=100kJ,/_\G_f^0(NO_2)=50kJ Find /_\G for the reaction at 298K

Answer»

<P>

Solution :For the given reaction, `/_\G^0=2/_\G_f(NO_2)^0-/_\G_(f(N_2O_4)^0`
`=(2xx50-100)kJ=0`
We know, `/_\G^0=-RTinK_p` or `0=-RTInK_p`
`:.K_p=1`
In the mixture, total NUMBER of MOLES of `N_2O_4` and
`NO_2=(5+5)mol=10mol`
So, in the mixture, `p_(N_2O_4)=5/(10)xx20"bar"=10"bar"`
`p_(NO_2)=5/(10)xx20"bar"=10"bar"`
`:.Q_p=(p_(NO_2)^2)/(p_(N_2O_4)^2)=((10^2)/(10))`bar=10bar
`Q_pgtK_p`, reaction will occur to a greater extent towards LEFT.
28.

In the hydration of an alkene carbocation is formed from :

Answer»

carbanion
oxonium ION
hydroxide ion
HYDRIDE ion

ANSWER :B
29.

In the following elimination reaction, hybridisation of carbon atom to which halogen is attached changes from

Answer»

`sp^2` to `sp^3`
`sp^3` to `sp^2`
`sp^2` to `sp^2`
`sp^3` to `sp^3`

ANSWER :B
30.

In the hydrides of VI A group elements, the acidic strength gradually increases from top to bottom. This is due to

Answer»

decreasesin the EN of the CHALCOGENS
increase in their Ka values
increase in the METALLIC strengthof chalcogen
increase in the m.p. of chalcogen

ANSWER :B
31.

In the hydrides of VIA elements largest bond angle and bond length is observed respectively in

Answer»

`H_(2)O,H_(2)O`
`H_(2)Po, H_(2)O`
`H_(2)O, H_(2)Po`
`H_(2)S, H_(2)SE`

ANSWER :C
32.

In the following dehydration of diol with H_(3)PO_(4) following product is formed such that isotopic .^(18)O goes H_(2)O. Explain.

Answer»


SOLUTION :N//A
33.

In the following electron dot structure, calculate the formal charge from left ot righ nitrogen atom. underset(..)overset(..)(N)=N=underset(..)overset(..)(N)

Answer»

`-1,-1,+1`
`-1,+1,-1`
`+1,-1,-1`
`+1,-1,+1`

Solution :FORMAL charge on an atom- total no. of VALENCE electron in FREE atom- total no. of non bonding electrons `-1/2` total no. of bonding electrons
`underset(1)underset(..)OVERSET(..)(N)=underset(2)(N)=underset(3)underset(..)overset(..)(N)`
`N_(1)=5-4-1/2xx4=5-6=-1`
`N_(2)=5-0-1/xx8=5-4=+1`
`N_(3)=5-4-1/2xx4=-1`
34.

In the hydrides of group 16th elements the bond angles decrease in the order, H_2O, H_2S, H_2Se, H_2Te. How would you account for this

Answer»

SOLUTION :`80.19%`
35.

In the following electrochemical cell : Zn(s)abs(zn^(+2)) abs(H^(+))Pt(H_(2)),E^(o)""_(cell) = E_(cell) This will be true when :

Answer»

<P>`[Zn^(2+)]=[H^(+)]=1 M and P_(H_(2))= 1 atm`
`[Zn^(2+)]=0.01 M,[H^(+)]=0.1 M and P_(H_(2))= 1 atm`
`[Zn^(2+)]=1 M,[H^(+)]=0.1 M and P_(H_(2))= 0.01 atm`
all of the above are TRUE

ANSWER :D
36.

In the hydrated choride of magnesium MgCl_(2).(H_(2)O)_(x)then 'x' is

Answer»


ANSWER :6
37.

In the following electrochemical cell Zn underset(Ө)(|)Zn^(2+)||H^(+)underset(o+)(|)Pt(H_(2)) E_(cell)^(o)=E_(cell), this will be when:

Answer»

`[Zn^(2+)]=[H^(+)]=1M and pH_(2)=1atm`
`[Zn^(2+)]=0.01M,[H^(+)]=0.1M and pH_(2)=1atm`
`[Zn^(2+)]=1M,[H^(+)]=0.1M and pH_(2)=0.1atm`
`[Zn^(2+)]=[H^(+)]=0.1M and pH_(2)=0.1atm`

Answer :A::B::C::D
38.

In the hydrated chloride (MgCl_(2)xH_(2)O) of Me, the value of x'is

Answer»


Solution :Carnllite `-KCI MG Cl_(2).6H_(2)O`
39.

In the following conversion Which of the following reagents is suitable ?

Answer»

`NH_(2)NH_(2),KOH,DMSO`
`NaBH_(4)`
`Zn,Hg` concentrated `H_(2)SO_(4)`
`LiAlH_(4)`

Solution :
ACETAL is hydrolysed in acidic MEDIUM so clemmensen REDUCTION is not used.
40.

In the Hofmann 's method for separation of 1^(@), 2^(@) and 3^(@)amines, the reagent used is

Answer»

ACETYL chloride
benzene SULPHONYL chloride
diethyl oxalate
nitrous acid.

Answer :C
41.

In the following concentration cell Ag(s) // AgCl "(saturated)"// // AgNO_3(aq) (0.1M)//Ag_((s)), K_(SP) " of AgCl"=1 xx 10^(-10)The cell potential will be

Answer»

`E_("CELL") = 0.295V `
`E_("cell")=0.236 V `
`E_("cell")=(0.059)/(1)log""([Ag^(+)]_("cathode"))/(sqrt(K_(SP) " of " AgCl))`
`E_("cell")=E_("cell")^(@) + (0.059)/(1)log ""(sqrt(K_(SP) " of AgCl"))/([Ag^(+)]_("cathode"))`

Solution :`E=0 - (0.0591)/(1) log""([Ag^(oplus)]_a)/([Ag^(oplus)]_c), E = (-0.0591)/(1) log""(10^(-5))/(10^(-1)) = - (0.0591)/(1) xx (-4) = 0.2364V `
42.

In the Hofmann bromamide degradation reaction, the number of moles of NaOH and Br_(2) used per mole of amine produced are

Answer»

one mole of NAOH and one mole of `Br_(2)`
FOUR MOLES of NaOH and two moles `Br_(2)`
two moles of NaOH and two moles of `Br_(2)`
four moles of NaOH and one mole of `Br_(2)`

Solution :`RCONH_(2)+Br_(2)+ 4NaOH to R-NH_(2)+Na_(2)CO_(3)+2NaBr+2H_(2)O`
43.

In the following compounds the order of basicly is

Answer»

`IVgtIgtIIIgtII`
`IIIgtIgtIVgtII`
`IIgtIgtIIIgtIV`
`IgtIIIgtIIgtIV`

ANSWER :D
44.

In the Hansging method Magnesia is reduced using.

Answer»

SI
`CaC_(2)`
`FESI`
Cocke

Answer :D
45.

In the following compounds : The order of basicity is

Answer»

`IV gt I gt III gt II`
`III gt I gt IV gt II`
`II gt I gt III gt IV`
`I gt III gt II gt IV`

Solution :See Ultimate PREPARATORY PACKAGE of this unit.
46.

In the following compounds the order of basicity is

Answer»

`IV gt I gt II gt II`
`III gt I gt IV gt II`
`II gt I gt III gt IV`
`I gt III gt II gt IV`

SOLUTION :Delocalization of 1.p on .N.-atom `UARR b.c darr`
47.

In the Hanging method of reduction of Magnesia with carbon, the backward reaction is prevented by quenching the mixture of magnesium vapour and cartoon monoxide with

Answer»

HCl GAS
CO gas
`CAF_(2)`
`H_(2)`

ANSWER :D
48.

In the following compounds, the order of acidity is:

Answer»

IIIgtIVgtIgtII
IgtIVgtIIIgtII
IIgtIgtIIIgtIV
IVgtIIIgtIgtII

Answer :D
49.

In the following compounds The order of basicity is

Answer»

`IV gt I gt III gt II`
`III gt I gt IV gt II`
`II gt I gt III gt IV`
`I gt III gt II gt IV`

Solution :Piperidine (I) is a `2^(@)` alphatic amine. As such it is most basic with `K_(b)=2xx10^(-3)`. Pyrrole (IV) with `K_(b)=2.5xx10^(-14)` is least basic of all the four. In pyrrole, the N is `sp^(3)` hybridised and the lone pair on N is involved in `pi`-electron cloud. Thus is due to non availability of lone pair on N for sharing with acids, it is least basic of the four. In pyridine (II) N is `sp^(2)` hybridised and the UNPAIRED electron in the unhybridised p-orbital is involved in `pi`-electron cloud. As such the lone pair on N PRESENT in `sp^(2)`-hybridised orbital is available for sharing with acids. Thus it is more basic than pyrrole. The value of `K_(b)` for pyridine is `2.3 xx 10^(-9)`. In (III) the lone pair on N is LESS readily available because of electronegative O atom present in the skeleton RING. Thus (III) is less basic than (I).
50.

In the following compounds piperidine (I), pyridine (II), morpholine (III) and pyerrole (IV), the order of basicity is :

Answer»

`IVgtIgtIIIgtII`
`IIIgtIgtIVgtII`
`IIgtIgtIIIgtIV`
`IgtIIIgtIIgtIV`

ANSWER :D