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.

Which element in periodic table has highest ionisation energy. (IE) ?

Answer»


ANSWER :He (HELIUM) has HIGHEST IONISATION ENERGY.
Discussion
2.

Write the resonating structures for the following molecules. N_(2) O

Answer»

SOLUTION :
Discussion
3.

The work function (phi) of some metals is listed below. The number of metals which will show photoelectric effect when light of 300 nm wavelength falls on the metal is {:("Metal",Li,Na,K,Mg,Cu,Ag,Fe,Pt,W),(phi(eV),2.4,2.3,2.2,3.7,4.8,4.3,4.7,6.3,4.75):}

Answer»


Solution :Energy associated with the incident photon `= (hc)/(lamda)`
i.e., `E = ((6.6 xx 10^(-34) Js) (3 xx 10^(8) ms^(-1)))/((300 xx 19^(-9) m))`
`= 6.6 xx 10^(-19) J = (6.6 xx 10^(-19))/(1.6 xx 10^(-19)) EV = 4.12 eV`
`:.` Metals showing photoelectric effect will be Li, Na, K and Mg only i.e., 4 metals, (which have WORK FUNCTION less than 4.12 eV)
Discussion
4.

Which of the following is not a correct statement about electrochemical series of reduction potentials ?

Answer»

The standard ELECTRODE POTENTIAL of hydrogen is 0.00 volts.
Active non-metals have POSITIVE reduction potentials.
Active metals have NEGATIVE reduction potentials.
Metals which have positive reduction potentials are good reducing agent.

Solution :Metals with negative reduction potentials undergo OXIDATION and act as good reducing agents.
Discussion
5.

Water pollution is due to

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A agricultural DISCHARGES
Sewage and other WASTES
INDUSTRIAL effluents
All the above

Solution :Refer COMPREHENSIVE Review
Discussion
6.

Which of the following is not chemical combinations

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`C+O_(2) to CO_(2)`
`S+O_(2) to SO_(2)`
`2Al+N_(2) to 2AlN`
`2H_(2)O to 2H_(2)+O_(2)`

ANSWER :D
Discussion
7.

What are dimensions of Planck's constant. What other physical quantity has the same dimensions ?

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Solution :DIMENSIONS of PLANCK's constant, `H = kg m^(2) s^(-1)` Angular MOMENTUM `= mvr = kg (m s^(-1)) m = kg m^(2) s^(-1)` has the same dimensions (Remember from Bohr's POSTULATE, `mvr = n (h)/(2pi)`)
Discussion
8.

When 3*06of solid NH_(4)HS is introduced into a two - litre evacuated flask at 27^(@C,30% of the solid decomposes into gaseous ammonia and hydrogen sulphide. (i) Calculate K_(c) and K _(p) for the reaction at 27^(@)C. (ii) What would happen to the equilibrium when more solid NH_(4)HSis introduced into the flask ?

Answer»

Solution :` {:((i),NH_(4)HS(s),HARR,NH_(3)(s),+,H_(2)S(g)), ("Intial amount",3*06 g,,,,), (,=3*06//51 "mole",,,,),(,=0*06 "mole",,,,):}`
`{:("At eqm.",0*06-30/100xx0*06,0*018 "mole",0*018"mole"), (,=0*06-0*018,,), (,=0*042 "mole",,):}`
` {:("Eqm.conc",1,0*018//2,0*018//2),(,("being solid"),=0*009,=0*009"mol"L^(-1)):}`
` K_(c) = ([NH_(3)][H_(2)S])/([NH_(4)HS])=(0*009 xx 0*009)/1 = 8*1 xx10^(-5)"" ( [NH_(4)HS(s)] = 1 ) `
` K_(p)= K_(c) (RT)^(Delta n_(g)) = 2 -0 =2`
(II)As`K_(c) = [NH_(3)][H_(2)S] `and does not depend upon the amount of `NH_(4)HS`(s) . hence , therewill be no effect on equilibrium when more solid `NH_(4)HS ` is added.
Discussion
9.

What is order of intermolecular interaction in solid, liquid and gas ?

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Solution :Gas `to` LIQUID `to` Solid : ORDER of INTERMOLECULAR interaction INCREASE.
Discussion
10.

Which of the following anions is present in the chain structure of silicates ?

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`(Si_(2)O_(5)^(2))_(N)`
`(SiO_(3)^(2))_(n)`
`SiO_(4)^(4)`
`Si_(2)O_(7)^(6)`

Answer :B
Discussion
11.

Which of the following hydrogen bonds is relatively weake?

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N........ H-N
F........ H-F
N........... H-O
O ............. H-O

Answer :A
Discussion
12.

Which of the following pairs of ions are isoelectronic and isostructural ?

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`SO_(3)^(2-) , NO_(3)^(9-)`
`ClO_(3)^(-), SO_(3)^(2-)`
`CO_(3)^(2-), SO_(3)^(2-)`
`ClO_(3)^(-) , CO_(3)^(2-)`

SOLUTION :`SO_(3)^(2-) to SP^(3) to ` Pyramidal ` to 16 + 24 + 2 = 42 e^(-)`
`CIO_(3)^(-) to sp^(3) to ` Pyramidal` to 17 + 24 + 1 = 42 e^(-)`
`CO_(3)^(2-) to sp^(2) to ` TRIANGULAR planar ` to 6 24 + 2= 32 e^(-)`
` NO_(3)^(2-) to sp^(2) to ` Triangular planar ` to 7 + 24 + 1 = 32 e^(-)`
Thus, `SO_(3)^(2-) and CIO_(3)^(-)` are isoelectronic and
isostructureal .
Discussion
13.

Water gas is …………… .

Answer»

`H_(2)O`
`CO + H_(2)O`
`CO + H_(2)`
`CO + N_(2)`

ANSWER :C
Discussion
14.

Which of the following are correct about the reactionA + 2B hArr C + D

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`K_p=(n_C xx n_D)/(n_A xx (N_B)^2) xx ((P)/(RT))^(-1)`
`K_P=(n_C xx n_D)/(n_A xx (n_B)^2) xx ((P)/(Sigma N))^(-1)`
`K_p=(n_C xx n_D)/(n_A xx (n_B)^2) xx ((V)/(RT))`
`K_C=([C][D])/([A][B]^2)`

Solution :`K_(C)=([C][D])/([A][B]^(2))=(n_(C))/(n_(A))(n_(D))/(n_(B)^(2)) xx V, K_(P)=K_(C)(RT)^(-1)`
`=(n_(C)n_(D))/(n_(A)n_(B)^(2))((V)/(RT))=(n_(C)n_(D))/(n_(A)n_(B)^(2))((SUM n)/(P))`
Discussion
15.

Which of the following pairs is /are correctly matched ? I. Carbocation : electrophile II. Free radical : paramagnetic III. Carbene : Incomplete octet IV. Carbanion : Incomplete octet Select the correct answer using the codes given below :

Answer»

Only I
I and II
I, II III and IV
I, II and III

ANSWER :D
Discussion
16.

Which of the following is strongest acid ?

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ANSWER :C
Discussion
17.

Which of the following ions is not having the configuration of neon

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`F^-`
`Mg^(+2)`
`Na^+`
`CL^-`

SOLUTION :CONFIGURATION of NE=`1s^2 2s^2 2p^6`
`F^(-) =1s^2 2s^2 2p^6`
`Na^(+)=1s^2 2s^2 2p^6`
`Mg^(++)=1s^2 2s^2 2p^6`
`Cl^(-)=1s^2 2s^2 2p^6 3s^2 3p^6`
Discussion
18.

Whichtypeof metalusedin photoelectriccell giveexample .

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SOLUTION :Themetalwhichhas lowionizationenthalpyused inphotoelectriccelle.g. CS
Discussion
19.

Which type of force of atraction exist in HF ?

Answer»

London force
DIPOLE - Dipole force
INTERMOLECULAR H - bond ATTRACTION
All the given

Answer :D
Discussion
20.

Which one following mechanism will be followed when Tartiary butyl chloride is treated with alcoholic KOH?

Answer»

`S_(N^1)` MECHANISM
`E_1` mechanism
`S_(N^2)` mechanism
`E_2` mechanism

Solution :`E_2` mechanism
Discussion
21.

Write the general outer electronic configuration of s-, po, d- and f- block elements.

Answer»

Solution :GENERAL electronic configuration of outer most ORBITS :
s-block elements : `ns^(1-2)`
p-block elements : `ns^(2) np^(1-6)`
d-block elements : `(n -1) d^(1-10) ns^(0-2)`
f-block elements : `ns^(2) np^(6)`
Discussion
22.

Which of the following is a beta-elimination reaction ?

Answer»


`CHCl_3 + KOH overset(Delta)to C Cl_2`

Solution :`BETA`-elimination is that elimination reaction in which substrate looses two ATOMS from 1 &2 POSITION.

`NaNH_2` is strong BASE so give `beta`-elimination reaction.
Discussion
23.

Which of the following does not contain a peroxy bond

Answer»

`Na_2O_2`
`BaO_2`
`MnO_2`
`H_2S_2O_8`

ANSWER :C
Discussion
24.

What is the electronic configuration of the elements of group 14

Answer»

`ns^2 np^4`
`ns^2 np^6`
`ns^2 np^2`
`ns^2`

ANSWER :C
Discussion
25.

Write Lewis symbole for the following atoms and ions : S andS^(2 - ): Al and Al^(3+) , and H^(-)

Answer»

Solution :`._(16)S = 2, 8, 6 therefore ` Lewis symbol =` : overset (cdotcdot )(S):, S^(2-) ions = [ :UNDERSET(cdotcdot) overset( cdotcdot )S:]^(2-)`
` _(13)Al= 2,8,3 therefore` Lewis symbol`CDOT overset(cdot)Alcdot ,Al^(3+) ions [Al]^(3+)`
` _(1)H = 1therefore ` Lewis symbol= ` H^(cdot ), H^(-) ion = overset(H) (cdot)` .
Discussion
26.

Write Lewis structure or the following compounds and show formal charge on each atom . HNO_(3), NO_(2), H_(2)SO_(4)

Answer»

Solution :The Lewis structure of the FOLLOWING compounds and formal charge on each ATOM are as

Formal charge on an atom in a Lewis structure = (total number of valence electrons in free atom) - [total number of non-bonding (lonepairs) electrons) `(1)/(2)` [total number of bonding or shared electrons]
(i) Formal charge on H = 1 - 0 - `(1)/(2) xx 2 = 0 `
Formal charge on `N = 5 - 0 - (1)/(2) xx 8 = 1`

Formal charge on O (1) = 6 - 4- `(1)/(2) xx 4 = 0 `
Formal charge on`O(2) = 6 - 4 - (1)/(2) xx ` 4 =0
Formal charge on O(3) = 6- 6 - `(1)/(2) xx 2 = - 1 `
(ii)Formal charge on O(1) = 6 -4 - `(1)/(2) xx 4 = 0 `
Formal charge on `N = 5 - 1 - (1)/(2) xx 6 = + 1 `
Formal charge on O(2) `6 - 6 - (1)/(2) xx 2= -1 `
(iii)

Formal charge on H(1) or H(2) = 1 - 0 - `(1)/(2) xx 2 = 0`
Formal charge on O(1) or O(3)= 6 - 4 - `(1)/(2) xx 4 = 0 `
Formal charge on O(2) or O(4) = 6 - 6 - `(1)/(2) xx2 = -1`
Formal charge on S = 6 - 0 - `(1)/(2) xx 8 = + 2 `
Discussion
27.

What is green fuel ? Give the information about waste recycling.

Answer»

Solution :Fuel obtained from plastic WASTE has high octane rating. It contains no lead and is known as "green fuel".
Due to recent developments made in CHEMICAL and textile industries, clothes will be made from recycled plastic waste.
TECHNOLOGY has now been developed to produce electricity from the garbage. A pilot plant has been set up, where after removing ferrous metals, plastic, glass, paper etc. from garbage, it is mixed with water. It is mixed with water. It is then caltured with bacterial species for producing methane, which is known as biogas.
Biogas is used to produce electricity and the REMAINING PRODUCT is used as manure.
Discussion
28.

What will be the stability order of Group-14 ?

Answer»

`CX_2 LT SiX_2 lt GeX_2 lt SnX_2 lt PbX_2`
`CX_2 lt lt SiX_2 lt lt GeX_2 lt lt SnX_2 lt lt PbX_2`
`CX_2 lt lt SiX_2 lt lt GeX_2 lt lt SnX_2 lt PbX_2`
`CX_2 lt lt SiX_2 lt GeX_2 lt lt SnX_2lt PbX_2`

ANSWER :C
Discussion
29.

Which of the following alkene gives four monochloro (structural isomer) products after hydrogenation ?

Answer»

Pent-2-ene
2-Methylbut-2-ene
3-Methylhex-2-ene
2,3-dimethyl-but-2-ene

Answer :B
Discussion
30.

Which of the following pairs would have higher boiling points ?

Answer»

Solution :(a) (II) because carbonyl GROUP is more polar than DOUBLE bond.
(b) (I) acid forms dimar due to `H-`bonding.
( C) (II) cis-compound has high dipole moment `(mu)`, so more polar than trans-compound `(mu = 0)`
(d) (I) it forms `H-`bonding1 through `H` atom in `(-NH)` group.
( e) (II) it forms `H-`bonding
(f) (II) alcohols form `H`-bonding.
(G) (II) two `(OH)` groups can form more `H-`bonding with each other.
(h) (I) alcohold form `H-`bonding
(i) (II) because of high MOLECULAR mass and large size, have larger van der Waals forces of attraction.
Discussion
31.

What is added to increase the setting velocity of plaster of paris?

Answer»

Alum
Limestone
Borax
Common salt

Answer :C
Discussion
32.

When an amide is reduced with sodium/alcohol is yields

Answer»

PRIMARY AMINE
an alcohol
secondary amine
aldoxime

Solution :`R - OVERSET(O)overset(||)(C) - NH_(2) + 4 [H] overset(Na//alc.)rarr underset(1^(@) "amine")(R - CH_(2) - NH_(2) + H_(2)O`
Discussion
33.

What are the uses of Heavy Water ?

Answer»

Solution :a. Heavy water is USED as a coolant and MODERATOR for neutrons in nuclear REACTORS.
b. Heavy water is used in the preparation of deuterium and deuterated compounds.
C. It is used as a tracer element in metabolic processes.
Discussion
34.

The total number of acyclic isomers for C_(3)H_(4) is

Answer»

1
2
3
4

Answer :B
Discussion
35.

Which of the following refers to the original description of reduction?

Answer»

Addition of hydrongen
Addition ofelectropositive element
REMOVAL of oxygen
Removal of ELECTROPOSITIVE element

Solution : In the beginning , reduction was CONSIDERED as the removal of oxygen from a compound :
`2ZnO(s) overset(Delta)(rarr) 2ZN(s) +O_2(g)`.
Discussion
36.

Which properties of gas can be measured ?

Answer»

Solution :(i) Mass (ii) VOLUME (III) Temperature (IV) PRESSURE
Discussion
37.

Which one of the following will undergo S reaction faster?

Answer»




SOLUTION :
Discussion
38.

Which of the followingis similar to graphite ?

Answer»

`B_(4)C`
`B_(2)C`
`BN`
`B`

Solution :BN haslayeredstructuresimilar to graphite.
Discussion
39.

Which of the following conformers for ethylene glycol is most stable ?

Answer»




ANSWER :D
Discussion
40.

The thermochemical equation for solid and liquid rocaket fuel are given below 2Al(s) + 1(1)/(2)O_(g) rarr Al_(2)O_(3)(s) , Delta H = - 1667.8 kJ mol^(-1) H_(2)(g) + (1)/(2) O_(2)(g) rarr H_(2)O(l) , Delta H = - 285.9 kJ mol^(-1) (a) If equal masses fo aluminiumand hydrogen are used, which is a better rocket fuel? (b ) Determine Delta H for the reaction : Al_(2)O_(3)(s)rarr 2Al(s) + 1(1)/(2)O_(2)(g)

Answer»

Solution :(a) From the first given equation.
2 moles of Al `( i.e., 2 xx 27 g = 54G)` on combustion GIVE heat `= 1667.8 KJ`
`:. 1 g` of Al combustion givesheat ` = (1667.8 ) / ( 54) = 30.9kJ`
From the second given equation, 1 mole of `H_(2)( = 2g) ` on combustion gives heat `= 285.9 kJ`
`:.` 1 g of `H_(2)` on combustion gives heat `= (285.9) /( 2) = 142.95kJ`
Thus, `H_(2)` is a better rocket fuel.
(b) Writing the reverse of the first REACTION, we have
`Al_(2)O_(3)(s) rarr2Al(s) +1(1)/(2) O_(2)(g), DeltaH = + 1667.8 kJ mol^(-1)`
Thus, for the reaction given in part (b) of the problem, `Delta H = + 1667.8 kJ mol^(-1)`
Discussion
41.

What happens when quick lime is heated with silica?

Answer»

Solution :Quick lime (CaO) COMBINES with silica `(SiO_(2))` to FORM SLAG.
`CaO+SiO_(2) overset("HEAT") to CaSiO_(3)`
Discussion
42.

Which of the following is a redox reaction

Answer»

`CH_(3)COOH + C_(2)H_(5)OH rarr CH_(3) COOC_(2)H_(5)+H_(2)O`
`2NaOH + H_(2)SO_(4) rarr Na_(2)SO_(4) +2H_(2)O`
`Zn +CuSO_(4) rarr ZnSO_(4) +CU`
`NACL +AgNO_(3) rarr AGCL +NaNO_(3)`

Solution :
Discussion
43.

Which of the following atomic numbers represent group 13 elements ?

Answer»

13
53
31
81

Solution :Group 13 ELEMENTS have atomic number 5,13 31, 49 and 81.
Discussion
44.

Write the balanced equations for the reactions between (i) Na_(2)O_(2) and water (ii) KO_(2) and water (iii) Na_(2)O and CO_(2)

Answer»

Solution :(a) `Na_(2)O_(2) (s) + 2H_(2)O (l) to 2 NaOH (aq) + H_(2)O_(2) (aq)`
(B) `2KO_(2) (s) + 2H_(2)O (l) to 2 KOH (aq) + H_(2)O_(2) (aq) + O_(2)(g)`
or `4 KO_(2) (s) + 2H_(2)O (l) to 4KOH (aq) + 3O_(2) (g) `
(c) `Na_(2) O + CO_(2) to Na_(2) CO_(3)`
Discussion
45.

Which statement is incorrect

Answer»

Phenol is a weak acid
Phenol is aromatic compound
Phenol liberates `CO_(2)` from `Na_(2)CO_(3)` solution
Phenol is soluble in `NaOH`

Solution :Riemer-Tiemann reaction :

`:. C-C` bond is FORMED.
Hydroboration-oxidation:
`RCH=CR_(2)^(') underset((II) H_(2)O_(2), OH^(-))OVERSET((i) B_(2)H_(6))rarr R-underset(OH)underset(|)(CH)-CHR_(2)^(')`
`:. C-O` bond is formed.
Cannizzaro reaction:
`2RCHO+50% NaOH rarr RCH_(2)OH+RCOONa`
`:. C-OH` and `C=O` bonds are formed.
Reaction of `1^(@)` alcohol by PCC
`RCH_(2)OH underset([O])overset(PC C)rarrRCHO`
`:. C=O` bond is formed.
Discussion
46.

Tungsten has a density of 19.35 g cm^(-3) and the length of the side of the unit cell is 316 pm. The unit cell in the most important crystalline form of tungsten is the body centred cubic unit cell. How many atoms of the element does 50 g of the element contain ?

Answer»


ANSWER :`1.638xx10^23`
Discussion
47.

Write the structure of the alkene which on reductive ozonolysis gives butanone and ethanal.

Answer»

SOLUTION :
Discussion
48.

Which of the following will show geometrical isomerism?

Answer»




SOLUTION :N//A
Discussion
49.

Two elements 'P' and 'Q' combine to form a compound. Atomic mass of 'p' is 12 and 'Q' is 16. percentage of 'P' in the compound is 27.3. What will be the empirical formula of the compound ?

Answer»

`P_2Q_2`
PQ
`P_2Q`
`PQ_2`

SOLUTION :
EMPIRICAL FORMULA `=PQ_2`
Discussion
50.

Weight percentage of C , H and Cl in an organic compound are 16.27% , 0.67% and 72.2% respectively. If the vapour density is 73.75, What is its molecular formula?

Answer»


ANSWER :`C_(2)HCl_(3)O`
Discussion