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.

Unknown compound A on oxidation with hot basic KMnO, gives only one compound structureof which is given below. HOOC - (CH_2)_4 - COOH. Compound A will be

Answer»

`CH_3 - C -= C-(CH_2)_4 - C-= C-CH_3`
`CH_3-CH=CH-(CH_2)_4 - CH=CH_2`
`CH_3 - CH=CH-(CH_2)_4 - CH = CH-H_3`

SOLUTION :COMPOUND in DIBASIC acid HENCE compound should be cycloalkene
Discussion
2.

Which one of the following exhibits the largest number of oxidation states?

Answer»

`TI(22)`
`V(23)`
`Cr(24)`
`Mn(25)`

Answer :D
Discussion
3.

Which of the following equations are correct

Answer»

`MgCl_(2)*2H_(2)O overset(Delta)(to) Mg(OH)_(2)+2HCL`
`MgCl_(2)*6H_(2)O overset(Delta)(to) MgCl_(2)*2H_(2)O+4H_(2)O`
`MgO+C+Cl_(2) to MgCl_(2)+CO`
`MgSO_(4)*7H_(2)Ooverset(100K)(to)MgSO_(4)`

Solution :`MgSO_(4).7H_(2)Ooverset(423K)underset(-6H_(2)O)(to)MgSO_(4).H_(2)O`
Discussion
4.

Which of the following molecules can act as an oxidising as well as a reducing agent ?

Answer»

`H_(2)S`
`SO_(3)`
`H_(2)O_(2)`
`F_(2)`

ANSWER :C
Discussion
5.

Which form of carbon is used in making boot polish, printing ink, paint and black varnish

Answer»

Bone black
Graphite
Gas carbon
Lamp black

Solution :Lamp black is used in POLISH, INK & PAINTS
Discussion
6.

Which one of the following substituents at para-position is most effective in stabilizing the phenoixde , ion ?

Answer»

`-CH_(3)`
`-OCH_(3)`
`-COCH_(3)`
`-CH_(2)OH`

Answer :C
Discussion
7.

Which of the following compounds will not give Lassaigne's test for nitrogen ?

Answer»

`NH_(2)NH_(2)`
`C_(6)H_(5)NHNH_(2)`
`PhN = NPh`
`NH_(2)CONH_(2)`

Solution :`NH_(2)NH_(2)` does not have carbon to form NaCN needed for +ve Lassaigne's test.
Discussion
8.

Which of the following statements are true about semiconductors ?

Answer»

Silicon doped with electron RICH impurity is a p-type semiconductor
Silicon doped with an electron rich impurity is an n-type semiconductor
Delocalised electrons increase the CONDUCTIVITY of doped silicon
An electron vacancy increases the conductivity of n-type semiconductor

Answer :B::C
Discussion
9.

Write the Van der Waals equation for a real gas. Explain the correction term for pressure and volume.

Answer»

Solution :The vander equation for a real gas is
`(P+(an^(2))/(V^(2)))(V-nb)=nRT`
Pressure correction : the pressure of a gas is directly proportional to the FORCE created by the bombardment of molecules on the walls ofthe container. The speed of a molecule moving towards the wallof the container is REDUCED by the attractive Force EXERTED by is neighbours. Hence , the MEASURED gas pressure is lower than the ideal pressure of the gas. Hence, van der waals introduced a correction term to this effect .

Van der Waal' s found out the forces of attraction experienced by a molecule near the wall are directly proportional to the square of the the density of the gas
`P'" a "r^(2)`
`rho=n/V`
When n is the number of moles of gas and V is the volume of the container
`impliesP'alpha(n^(2))/(V^(2))`
`P'=(an^(2))/(V^(2))`
Where a is proportionality. Constant and depends on the natural of gas
Therefore ,
`P_("ideal")=P+(an^(2))/(V^(2))`
Volume correction: As very individual molecule of a gas occupies a certain volume. The actual volume is less than the volume of the container, V Van der waals introduced acorrection factorV ' to this effect . LET uscalculate the correction term by. Considering gas molecules as spheres.

V = excluded volume
Excluded volume for two molecules
`4/3pi(2r)^(3)`
`=8(4/3pir^(3))=8v_(m)`
Where v is a volume of a single molecule Excluded volume for single molecule
`(8V_(m))/(2)=4V_(m)`
Excluded volume for n molecule= `n(4V_(m))=nb` Where b is van der waals constant
which is equal to `4V_(m)`
`impliesV=nb`
`V_("ideal")=V-nb`
Replacing the corrected pressure and volume in the ideal gas equation of state for real gases as below.
`(P+(an^(2))/(V^(2)))(V-nb)=nRT`
The constants a and b are van der waals constants and their values vary with the natural of the gas. It is an appointment formula for the non- ideal gas.
Discussion
10.

What is the ratio of the radii of the 3rd orbits of He^(+) and Li^(2+) ?

Answer»

SOLUTION :n is constant and its value is 3.
`Z" of "He^(+)=2, Z" of "LI^(2+)=3`
`r_(n)=(0.529xxn^(2))/(Z)Å""(r_(1))/(r_(2))=(Z_(2))/(Z_(1))=(3)/(2) or 3:2`
Discussion
11.

Which of the following method can be used for preparation of anhydrous AlCl_(3)

Answer»

heating `AlCl_(3)6H_(2)O`
heating of MIXTURE of ALUMINA and coke in a CURRENT of dry chlorine
passing dry HCl gas over heated AL power
passing dry Cl over head Al

Solution :Heating of mixture of alumina and coke, .Al. powder heated with dry HCl as well as passing dry .Cl. over .Al..
Discussion
12.

Which of the following is not a general characteristic of equilibriuminvolving physical process

Answer»

EQUILIBRIUM is possible only in a closed system at a given temperature
The opposing PROCESS OCCUR at the same rate and there is a dynamic but stable condition
All the physical PROCESSES stop at equilibrium
All measurable properties of the system remains constant

Solution :Correct STATEMENT : Physical processes occurs at the same rate at equilibrium.
Discussion
13.

The volume of oxygen required for complete combustion of 0.25 cm^(3) of CH_(4) at S.T.P. is _____________cm^(3)

Answer»

0.25
0.5
0.75
1

Answer :B
Discussion
14.

Whichpropertiescan beexplainedby wavenatureand particlenatureof light.

Answer»

SOLUTION :WAVENATURE: Itexplainscatteringof lightandinterference .
Particlenature :It can explainphotoelectriceffectand backbody RADIATION.
Discussion
15.

Which reaction represents oxidising nature of H_2O_2 in acid medium

Answer»

`H_2O_2 + OH^(-) + 2E^(-) to 3OH^(-)`
`H_2O_2 + 2H^(+) + 2e^(-) to 2H_2O`
`H_2O_2 to 2H^(+) + O_2 + 2e^(-)`
`H_2O_2 + 2OH^(-) to 2H_2O + O_2 + 2e`

ANSWER :B
Discussion
16.

Which of the follow ing on the addition will cause deep red colour to disappeared ? underset("pale yellow")(Fe_(aq)^(3+)) + underset("colourless")(SCN_(aq)^(-)) hArr underset("deep red")([ Fe (SCN) ]_(aq)^(2+))

Answer»

`AgNO_(3)`
`HgCl_(2)`
`H_(2)C_(2)O_(4)`
`H_(2)O`

Solution :a) `Ag^(+)` ion removes `SCN^(-)`
`Ag^(+)` ion removes `SCN^(-) to AGCNS DARR`
b) `Hg^(2+)` ion remove `SCN^(-)`
`Hg^(2+) 2SCN^(-) to Hg(CNS)_(2) darr`
c) `C_(2)O_(4)^(2-)` ion remove `Fe^(3+)` by complex formation
`Fe^(3+)+3 C_(2)O_(4)^(2-) to [Fe(C_(2)O_(4))_(3)]^(3-)` complex SOLUBLE
Discussion
17.

What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4g of carbon dixide contained in a 9 dm^(3) flask at 27^(@)C ? .

Answer»

SOLUTION :`0.82 ATM`
Discussion
18.

Which among the following alkali metals exhibit the most metallic character?

Answer»

Na
Li
Cs
K

Answer :C
Discussion
19.

Total no. of isomeric alkadienes with the molecular formula C_(5)H_(8)

Answer»


SOLUTION :ISOMERIC alkadiens is EIGHT
Discussion
20.

Which one of the following substance is not used for preparing lyophillic sols?

Answer»

STARCH
Gum
Gelatin
METAL sulphide.

Solution :Metal sulphide do not form LYOPHILIC SOLS.
Discussion
21.

The values ofK_(p_(1)) and K_(p_(2)) for the reactions X hArr Y+Z" "…(1) and A hArr 2 B " "…(2) are in the ratio of 9:1 .If the drgree of dissociation kof X and A be equal , then total pressure at equilibrium (1) and (2) are in the ratio

Answer»

`3:1`
`1:9`
`36:1`
`1:1`

Solution :SUPPOSE total PRESSURE at equilibrium for reactions (1) and (2) are `P_(1) and P_(2)` respectively . Then
`{: (,X,hArr,Y,+,Z), (" Intial",1 "mole",,0,,0), ("At eqm",1-alpha,,alpha,,alpha"Total"=1+alpha), (,p_(X)=(1-alpha)/(1+alpa)P_(1),,p_(Y)=alpha/(1+alpha)P_(1),,p_(Z) =alpha/(1+alpha)P_(1)):}`
` K_(p_(1))= (alpha/(1+alpha)P_(1))^(2)/((1-alpha)/(1+alpha)P_(1)) = (alpha^(2) P_(1))/(1-alpha^(2))cong alpha^(2)P_(1)`
`{: ( ,A,hArr,2B,) , (" Intial" ,1 "mole",,0,) ,(" At eqm" ,1-alpha,,2 alpha,"Total" = 1+alpha):}`
`p_(A) = (1-alpha)/(1+alpha)P_(2), p_(B) = (2alpha)/(1+alpha)P_(2)`
`K_(p_(2))=(((2alpha)/(1+alpha)P_(2)))/((1-alpha)/(1+alpha)P_(2)) = (4alpha^(2))/(1-alpha^(2))P_(2)= 4 alpha^(2)P_(2)`
` K_(p_(1))/K_(p_(2)) = (alpha_(2)P_(1))/(4 alpha^(2)P_(2))=P_(1)/(4 P_(2))=9/1 ` (GIVEN )
or` (P_(1))/(P_(2))=36/1 = 36*1`
Discussion
22.

The type of hybrid orbitals used by the central atom in perchloate ion is

Answer»

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

ANSWER :A
Discussion
23.

What is false about Line's process?

Answer»

Method is USED for manufacture of dihydrogen
It involves the oxidation of iron by steam
It involves the reduction of `H_2O` by iron
It involves the oxidation of WATER gas

SOLUTION :Lenes Process :-
(i) `3FE + 4H_2O to Fe_3 O_4+ 4H_2`
(ii) `Fe_3 O_4+ 4COto 3Fe + 4CO_2`
Discussion
24.

Write the notes on diatomic molecules and polyatomic molecules. OR Explain the bond enthalpy.

Answer»

Solution :DIATOMIC Molecules :
`H_(2(g)) to 2H_((g)) ,Delta_(H-H)H^( Theta )=435.0 "kj/mol"`
The enthalpy change INVOLVED in this process is the bond DISSOCIATION enthalpy of H-H bond. It is the same as the enthalpy of atomization of dihydrogen. This is true for all diatomic molecules.
`CI_(2(g)) to 2CI_((g)) , Delta_(CI - CI) H^( Theta ) = 242 "kj/mol"`
`O_(2(g)) to 2O_((g)) , Delta_(O=O) H^( Theta ) = 428 "kj/mol"`
The bond dissociation enthalpy is the change in enthalpy when one mole of covalent bond of a gaseous covalent compound is broken to form products in the gaseous phase. "It is change in enthalpy to break one mole of covalent bond and to get product in its vapour phase."
Polyatomic Molecules : In the case of polyatomic molecules, bond dissociation enthalpy is different for different bonds within the same molecules.
e.g., `CH_(4(g)) to C_((g)) + 4H_((g)) , Delta_(a) H^( Theta ) = 1665 "kj mol"`
In methane, all the four C - H bonds are identical in bond length and energy. However, the energies required to break the individual C - H bonds in each successive step differ :
`CH_(4(g)) to CH_(3(g)) + H_((g)) , Delta_("bond") H^( Theta ) = + 427 "kj mol"^(-1)`
`CH_(3(g)) to CH_(2(g)) + H_((g)) , Delta_("bond")H^( Theta ) = +439 "kj mol"^(-1)`
`CH_(2(g)) to CH_((g)) + H_((g)) , Delta_("bond")H^( Theta ) = +452 "kj mol"^(-1)`
`CH_((g)) to C_((g)) + H_((g)) , Delta_("bond")H^( Theta ) = +347 "kj mol"^(-1)`
Therefore,
`CH_(4(g)) to C_((g)) + 4H_((g)), Delta_(a) H^( Theta )= 1665 "kj mol"^(-1)`
In such cases we use mean bond enthalpy of C-H bond.
for example in `CH_(4) , Delta_(C-H) H^( Theta )` is calculated as, `Delta_(C-H) H^( Theta ) = (1)/(4) (Delta_(a) H^( Theta ) )= (1)/(4) (1665) = 416 "kj/mol"`
That means C-H bond enthalpy in methane is 416 kJ/mol. It has been found that mean C-H bond enthalpies differ slightly from compound to compound.
`Delta_(r) H^( Theta ) "bond enthalpies"_("reactants") - sum "bond enthalpies"_("products")`
THUS the net enthalpy change of a reaction is the amount of energy required to break all the bonds in the reactant molecules minus the amount of energy required to break all the bonds in the product molecules. This relationship is approximate and is valid when all substances in the reaction are in gaseous state.
Table - (a) : Some Mean Single Bond Enthalpies in kJ `"mol"^(-1)` at 298 K
Discussion
25.

Whichimportantpropertydid Mendeleevuse toclassifythe elementin hisperiodictable ?

Answer»

SOLUTION :mendeleev used theatomicmassesof the elementin classifyingthe ELEMENTS inhispreidioctable.
According toMendeleev's LAW thepropertiesof ELEMENTARE aperiodicfunction of theiratomicmasses.
Discussion
26.

Which of the following is not the correct use of caustic soda ?

Answer»

For mercerizing cotton
In the manufacture of artificial SILK
In refrigeration
To prepare soda LIME 

ANSWER :C
Discussion
27.

Two colourless gases on mixing formed dense white fumes. These are :

Answer»

`NH_(3) " and " SO_(2)`
`SO_(2)`and STEAM
`NH_(3) " and " HCl`
`NH_(3) " and " HNO_(2)`

SOLUTION :`NH_(3)` and HCl COMBINE to form dense WHITE fumes of `NH_(4)Cl`
`NH_(3) + HCl rarr underset(("White fumes"))(NH_(4)Cl)`
Discussion
28.

What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of 1Cl was 0.78 M ? 2I Cl (g) hArr I_(2) (g) + Cl_(2) (g), K_(C) = 0.14

Answer»

Solution :Suppose at EQUILIBRIUM the molar CONCENTRATION of both `I_(2) (g)` and `Cl_(2) (g)` is x mol `L^(-1)`
`{:( ,2I Cl (g) , HARR , I_(2) (g) + Cl_(2) (g)) , ("Initial molar conc." , 0.78 M , , 0 "" 0), ("Eqn. molar conc." , (0.78 - 2x) M , , x "" x):}`
`K_(C) = ([I_(2) (g)][Cl_(2) (g)])/([I Cl (g)]^(2)) = ( (x) xx (x))/((0.78 - 2x)^(2))`
`(x)/((0.78 - 2x)) = (0.14)^((1)/(2)) = 0.374` or `x= 0.374 (0.78 - 2x)`
`x = 0.292 - 0.748x ` or `x = 1.748 x = 0.292 , x = (0.292)/(1.748) = 0.167`
`[I Cl] = (0.78 - 2 xx 0.167) = (0.78 - 0.334) = 0.446 M`
`[I_(2)]= 0.167 M , [Cl_(2)] = 0.167 M`
Discussion
29.

When the electron in the .H. atom jumps from the fifth orbit to the second orbit, the spectral line emitted is found in

Answer»

VISIBLE region
Ultraviolet region
Near IR region
Far IR region

Solution :BALMER SERIES , `n_1 = 2 , n_2 = 5`
Discussion
30.

Which of the following species have the same bond order?

Answer»

`CN^(-)andCN^(+)`
`O_(2)^(-) and CN^(-)`
`NO^(+) andCN`
`CN and NO^(-)`

ANSWER :C
Discussion
31.

Which one is not true?

Answer»

The catalyst accelerates the reaction
The catalyst is unchanged at the END of the reaction
In a reversible reactionthe catalyst alters the EQUILIBRIUM position
A SMALL QUANTITY of catalyst is oftensufficent to bring about considerable amount of reaction.

Answer :C
Discussion
32.

What is the condition of precipitation using solubility product principle?

Answer»

SOLUTION :If the value of the ionic product is greater than the value of the solubility product, PRECIPITATION occurs. i.e., `(Q_(SP)gtK_(sp))`.
Discussion
33.

Which of the following homogeneous catalyst used in the conversion of ethyl acetate into ethanol ?

Answer»

`H^(+)`
`I^(-)`
Ni, oil and `H_(2)`
`Al_(2) O_(3)`

SOLUTION :`H^(+)` ion is dissolved form with reaction system.
Discussion
34.

The s-subhells have ____shape and the p-subshells have____

Answer»

SOLUTION :SPHERICAL , DUMB BELL SHAPE .
Discussion
35.

The wavelengthrangeof the visiblespectrumextendsfromvloler(400nm)to red(750nm)Expressthesewavelengthin frequency(Hz)

Answer»

SOLUTION :forultravioler 400nm= 400 `xx 10^(9)m= lambda`
C=velocityof lightin VACUUM= 30.`xx10^(8) ms^(-1)`
`v=(c )/(lambda) = (3.00xx 10^(8)ms^(-1))/(400 xx 10^(9)m)`
Wavelength`= lambda= 750nm = 750xx 10^(9) m`
and v=c= 30`xx 10^(8)ms^(-1)`
`v=(c )/(lambda )= (3.0xx 10^(8) ms^(-1))/(750 xx 10^(9 ) m)`
Therangeof visiblespectrumis from `40xx 10^(14)`
hz to7.5 `xx 10^(14) Hz`in terms offrequecny units.
Discussion
36.

Unit of Avogadro's number is

Answer»

MOL
G
`mol^(-1)`
no UNIT.

ANSWER :A
Discussion
37.

What iare the uses of cabon tetrachloride?

Answer»

Solution :(i) Carbon tetrachloride im uscd as a dry cleanng apent.
(II) it is used as a solvent LOR oils, lats and waxes.
(iii) As the vapours of `C Cl_4` is non-combustible,it is used the name pyrene for extinguishing the FIRE CAUSED by oil (or)petrol.
Discussion
38.

Write the IUPAC names of the following compounds. (i) CH_(3)-underset(CH_(3))underset(|)(CH)-underset(CH_(2)-CH_(3))underset(|)(CH)-CH_(2)-CH_(3) (ii) CH_(3)-CH_(2)-underset(COOH)underset(|)(CH)-CH=CH_(2) (iii) HOOC-underset(CH_(3))underset(|)overset(CHO)overset(|)C-CH_(2)-CH_(2)-CH_(2)-CH_(3)

Answer»

SOLUTION :(i) 3-ethyl-2-methylpentane (II) 2-ethyl but-3-enoic ACID
(III) 2-formyl-2-methylheptanoic acid
Discussion
39.

When acetylene is passed through red hot iron tube, compound X is formed. Which one of the following reactions will yield X as the major product?

Answer»

`C_6H_5SO_3H + NaHCO_3 rarr`
`C_6H_5Cl + H_2O OVERSET(DELTA)(rarr)`
`C_6H_12 + 3H_2 overset(N i)(rarr)`
`C_6H_5COONa + NaOH underset(Delta)overset(+CaO)(rarr)`

Answer :D
Discussion
40.

When 0.1mole of a gas absorbs 41.75 J of heat, the rise in temperature occursequal to 20^(@)C. The gas must be

Answer»

triatomic
diatomic
polyatomic
monoatomic

Solution :`C_(V) ` ( heat absorbedper degree rise per MOLE)
`=( 41.75J)/( 0.1 mol xx 20^(@)) = 20.875 JK^(-1) mol^(-1)`
`C_(p) = C_(v) + R = 20.875 + 8.314 JK^(-1) mol^(-1)`
`= 29.189 JK^(-1) mol^(-1)`
`(C_(p))/( C_(v)) = ( 29.189)/( 20.875) = 1.40`. Hence, the GAS is diatomic.
Discussion
41.

Two formulal to calculate number of milli equivalents (mlQ) Numbr of miliequivalents =("weight")/("GEW")xx1000 Numbr of milliequivalents= volume in ml xx Normality of solution 0.25 grams of pure CaCO_(3) neutralised 25 ml dilue HCl normality of HCl solution is

Answer»

0.1 N
0.5 N
0.25 N
0.2 N

SOLUTION :No. of Meq of `CaCO_(3)=(0.25)/(50)xx1000`
No. of Meq of HCL = `25xx` NORMALITY of the solution
No. of Meq of `CaCO_(3)` = No. of Meq of HCl
`therefore` Normality of HCl solution = 0.2N
Discussion
42.

Which of the following can be used for resolving racemic carboxylic acid.

Answer»

`(-)Ph - undersetoverset(|)(CH_3)(C )H -NH_2`
`(PM) - undersetoverset(|)(CH_3)(C ) H_3 - NH_2`
`Me - NH_2`
`Me_2 CHNHMe`

SOLUTION :(-)`Ph-UNDERSET(CH_3)underset(|)CH-NH_2`
Discussion
43.

The solubility product of Zr(OH)_(2) is 4.5xx10^(-17) "mol"^(3)L^(-3). What is solubility?

Answer»

SOLUTION :`2.6 XX 10^(-6) M`
Discussion
44.

Which of the following trimethyl cyclohexanes is the least stable

Answer»




SOLUTION :GROUPS at AXIAL is lighty UNSTABLE
Discussion
45.

The set representing the correct order of ionic radii is

Answer»

`Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+)`
`Li^(+) gt Na^(+) gt Mg^(2+) gt Be^(2+)`
`Mg^(2+) gt Be^(2+) gt Li^(+)gt Na^(+)`
`Li^(+) gt Be^(2+) gt Na^(+) gt Mg^(2+)`

Solution :The ionic radii of alkali metalions are larger thanthose of the corresponding alkaline earth metal IONS . ALSO ionic radii increase down thegroup . Therefore , the ionic size radii DECREASE in the order :
`Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+) ` i.e., option (a) is CORRECT .
Discussion
46.

Which hybridisation is found in HCIO_4 and HCIO_3?

Answer»

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

ANSWER :A
Discussion
47.

Which of the following is covalent ?

Answer»

NaCl
KCl
`BeCl_(2)`
`HgCl_(2)`

Solution :Among `Na^(+) , K^(+) , Be^(2+)` and `MG^(2+) , Be^(2+)` has the SMALLEST size and is also most ELECTRONEGATIVE . THEREFORE , `BeCl_(2)` is covalent .
Discussion
48.

True statement about above reaction :

Answer»

Reagent involve stereospecific syn addition of H and OH SPECIES .
Product OBTAINED is trans isomer.
Boron atom acts as electrophile
Two stereoisomers are obtained as product.

Answer :A::B::C::D
Discussion
49.

What is the correct representation for the solubility product of SnS_(2) ?

Answer»

`[SN^(2+)][S^(2-)]^(2)`
`[Sn^(4+)][S^(2-)]^(2)`
`[Sn^(2+)][2S^(2-)]^(2)`
`[Sn^(2+)][2S^(2-)]^(2)`

Answer :B
Discussion
50.

What does the equilibrium constant K lt 1 indicate ?

Answer»

Solution :The reaction does not PROCEED MUCH in the FORWARD DIRECTION.
Discussion