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.

Oxides of sulphur (SO_(2),SO_(3)) are due to

Answer»

buring of sulphur containing fossil ORE
roasting and SMELTING of sulphide ore
oxdation by air `H_(2)O_(2)` and `O_(3)`
All of the above

Solution :(a) `S(in fossil FUEL)+O_(2) rarr SO_(2)`
(b) `2CuFeS_(2)+5.5O_(2)underset("Roasting")overset("Smelting")(rarr) Cu_(2)O+2FeO+4SO_(2)`
(c ) `SO_(2)+O_(3)rarr SO_(3)+O_(2)`
`SO_(3)+O_(3) rarr SO_(3)+O_(2)`.
Discussion
2.

Oxides of nitrogen

Answer»

are TOXIC to living TISSUES
CAUSE respiratory diseases in children
reted the rate of PHOTOSYNTHESIS

Solution :`NO,NO_(2)` etc., are toxic to living tissues and irritant to children . They also retard the rate of photosynthesis.
Discussion
3.

Oxides of indium and thallium are basic in their properties .

Answer»

SOLUTION :TRUE STATEMENT
Discussion
4.

Oxides of beryllium and magnesium are ...... in water.

Answer»

Insoluble
Partially soluble
Soluble
Both (B) and (C)

ANSWER :B
Discussion
5.

Oxides of alkaline earth metals are stable due to

Answer»

HIGH lattice ENERGY
Low IP VALUES of alkaline earth metals
Low electronegativites alkaline earth metals
All of above

Answer :1
Discussion
6.

Oxidesand hydroxidesof alkaloineearthmetalsEXCEPT berylliumare ______in nature.

Answer»

ACIDIC
BASIC
amphoteric
neutral

ANSWER :B
Discussion
7.

Oxide that is most acidic

Answer»

`Cl_2O_7`
`SO_3`
`P_4O_10`
`N_2O_5`

ANSWER :A
Discussion
8.

oxidation states of P in H_(4)P_(2)O_(5),H_(4)P_(2)O_(6),H_(4)P_(2)O_(7) are respectively

Answer»

<P>`+3,+5,+4`
`+5,+3,+4`
`+5,+4,+3`
`+3,+4,+5`

Solution :O.N of P in `H_(4)P_(2)O_(5)=4(+1)+2x+5(-2)=0`
or X=+3
O.N of p in `h_(4)P_(2)O_(6)=4(+1)+2x+6(-2)=0`
or x =+4
O.N of p in `H_(4)P_(2)O_(7)=4(+1)+2x+7(-2)=0`
or x=+5
Discussion
9.

Oxidation states of the metal in the mineral haematite and magnetite ,respectively are

Answer»

II, III in haematite and III in magnetite
II, III in haematite and II in magnetite
II in haematite and II and III in magnetite
III is haematite and II and III in magnetite

Solution :In haematite `(Fe_(2)O_(3))` , O.S of FE is III white in magnetite `(Fe_(3)O_(4))` = 2 FEO.`Fe_(2)O_(3)`
O.S of Fe is II and III .
Discussion
10.

Oxidation states of P in H_(4)P_(2)O_(5),H_(4)P_(2)O_(6),H_(4)P_(2)O_(7) respectively are

Answer»

`+3, +5, +4`
`+5, +3, +4`
`+5, +4, +3`
`+3, +4, +5`

ANSWER :D
Discussion
11.

Oxidation states of P in H_(4)P_(2)O_(5),H_(4)P_(2)O_(6),H_(4)P_(2)O_(7) are:

Answer»

`+3,+5,+4`
`+5,+3,+4`
`+5,+4,+3`
`+3,+4,+5`

Solution :`H_(4)P_(2)O_(5),4+2x-10=0,X=+3`
`H_(4)P_(2)O_(6),4+2X-12=0,X=+4`
`H_(4)P_(2)O_(7),4+2x-14=0,X=+4`
Discussion
12.

Oxidation states of P in H_4P_2O_5, H_4P_2O_6 and H_4P_2O_7 are respectively :

Answer»

`+3, +5 and +4`
`+5, +3 and +4`
`+5, +4 and +3`
`+3, +4 and +5`

ANSWER :D
Discussion
13.

Oxidation state of terminal sulphur atoms in S_(4)O_(6)^(2-)02 (tetra thionate ion) are

Answer»


SOLUTION :`BARO-UNDERSET(O)underset(||)OVERSET(O)overset(||)(S^(overset+5))-overset(0)S-overset(0)S-underset(O)underset(||)overset(O)overset(||)(S^(overset+5))-barO`
Discussion
14.

Oxidation state of .S. in S_8molecule is

Answer»

0
`+2`
`+4`
`+6`

Solution :`S_8`molecule is a ELEMENTAL from of sulphur so, oxidation state is ZERO.
Discussion
15.

Oxidation state of phosphorus in pyrophosphosphate ion (P_(2)O_(7)^(-4)) is

Answer»

<P>`+7`
`+3`
`+8`
`+5`

SOLUTION :`P_(2)O_(7)^(-4)`
`2x +7 (-2) = 4`
`2x = +10 rArr X = +5`
Discussion
16.

Oxidation state of oxygen is -1 in the compound :

Answer»

`NO_2`
`MnO_2`
` PbO_2`
` Na_(2)O_2`

SOLUTION :`{:(,MnO_2),(underset("sodium peroxide")(Na_(2)overset(-1)(O_(2))),pbO_2),(,NO_2):}}` are DIOXIDES
Discussion
17.

Oxidation state of oxygen in potassium superoxide is

Answer»

`-1//2`
`-1`
`-2`
0

Answer :A
Discussion
18.

Oxidation state of oxygen in H_2O_2is

Answer»

`-2`
`-1`
`+1`
`+2`

Solution :`H_2overset(-1)(O_2)`in peraoxides oxidation STATE of OXYGEN is – 1 .
Discussion
19.

Oxidation state of oxygen in F_2O is

Answer»

`+1`
`+2`
`-1`
`-2`

ANSWER :B
Discussion
20.

Oxidation state of oxygen in H_(2)O_(2) is

Answer»

`-1`
`-2`
`+1`
`+2`

ANSWER :A
Discussion
21.

Oxidation state of oxygen atom in potassium superoxide is

Answer»

`-(1)/(2)`
`-1`
`-2`
0

Answer :A
Discussion
22.

Oxidation state of nitrogen is incorrectly given for M {:("Compound ","Oxidation State"),("a)" [Co(NH_3)_5Cl]Cl_2 ,-3),("b)" NH_2OH,-1),("c)" (N_2H_5)_2SO_4,+2),("d)" (Mg_(3))N_2,-3) :}

Answer»


SOLUTION :`(N_2H_5)_(2)SO_(4),4x+10+6-8=0,`
`4x=-8,x=-2`
Discussion
23.

Oxidation state of Ni in Ni(CO)_(4) is

Answer»

0
4
8
2

Answer :A
Discussion
24.

Oxidation state of N in N_(3)H is

Answer»

`+1//3`
`+3`
`-1//3`
`-1`

ANSWER :C
Discussion
25.

Oxidation state of K in KO_(2) is same as that in :

Answer»

`KO_(3)`
`K_(2)O_(2)`
`K_(2)O`
`KOH`

SOLUTION :Alkali METALS show oxidation STATE of +1 (ALWAYS) in combined state.
Discussion
26.

Oxidation state of Fe in K_(4)[Fe(CN)_(6)]

Answer»

`+6`
`+4`
`+2`
`+5`

SOLUTION :`x+4(+1)+6(-1)=0implies x = +2`
Discussion
27.

Oxidation state of Fe in Fe_(3)O_4 is

Answer»

`+2`
`+3`
`+8//3`
`+2//3`

ANSWER :C
Discussion
28.

The oxidation state of Fe in Fe_(3)O_(8) is

Answer»

`(3)/(2)`
`(4)/(5)`
`(5)/(4)`
`(16)/( 3)`

ANSWER :D
Discussion
29.

Oxidation state of each CI in CaOCI_(2) is / are

Answer»

0
`+1`
`-1`
`+1,-1`

Solution :`CaOCI_(2)` is ACTUALLY `CA^(2+)OCI^(-)CI^(-)` Therefore the O.N of the two CI ATOMS are +21 and -1
Discussion
30.

Oxidation state of Cl in HOCI is _____

Answer»

`-1`
`+1`
`+3`
`+2`

ANSWER :B
Discussion
31.

Oxidation state of boron in Magnesium boride

Answer»

`-3`
`+3`
`+1`
`-1`

ANSWER :A
Discussion
32.

Oxidation state +4 is less common in

Answer»

C
Si
Ge
Pb

Answer :D
Discussion
33.

Oxidation product of acetylene with chromic acid is

Answer»

Acetic acid
Oxalic acid
Acetone
ACETYLENE dicarboxylic acid

Solution :`CH -= CH + (O) + H_2O UNDERSET("acid")overset("Chromic")to CH_3COOH`
Discussion
34.

Oxidation potential of Zn, Cu, Ag are 0.76V, -0.34V, -0.80V, respectively then write down order of tendency of losing e^(-).

Answer»

Solution :`ZngtCugtAg` (Greater the VALUE of oxidation POTENTIAL, greater the `e^(-)` releasing CAPACITY.)
Discussion
35.

Oxidation of toluene withCrO_(3) in presence of(CH_(3)CO)_(2)Ogives a product (A) which onhydrolysis forms Benzaldehyde. A is ___

Answer»

Chromoum complex
Benzlidene diacetate
Benzophenone
Benzal chloride

Answer :2
Discussion
36.

Oxidation of toluene by acidic KMnO_(4) gives poor yield of benzoic acid while oxidation of p-nitrotoluene gives good yield of p-nitrobenzoic acid. Why?

Answer»

Solution :Oxidant is an electrophile, it can attack and destroy the ring in acse of TOLUENE. But in p-nitrotoluene, the -`NO_(2)` GROUP deactivates the ELECTROPHILIC attack on benzene NUCLEUS and thus INCREASES yield of p-nitrobenzoic acid.
Discussion
37.

Oxidation of sulphur dioxide into sulphur trioxide in the absence of a catalyst is a slow process but this oxidation occurs easily in the atmosphere. Explain how does this happen. Give chemical reactions for the conversion of SO_2 into SO_3

Answer»

SOLUTION :The presence of particulates in the air CATALYSES OXIDATION of `SO_2` to `SO_3` (`2 SO_2+ O_2 overset"Particulates " to 2SO_3`)
Discussion
38.

Oxidation of sulphur dioxide into sulphur trioxide in the absence of a catalyst is a slow process but this oxidation occurs easily in the atmosphere. Explain how does this happen. Give chemical reactions for the conversion of SO_2 into SO_3.

Answer»

Solution :The oxidation of SULPHUR DIOXIDE into sulphur trioxide can occur both photochemically or non-photochemically. In the NEAR ULTRAVIOLET region, the `SO_2` molecules react `O_3` photochemically.
`SO_2 + O_3 overset(hv)to SO_3 +O_2`
`2SO_2 + O_2 overset(hv)to 2SO_3`
Non-photochemically, `SO_2` may be oxidised by molecular oxygen in presence of dust and soot particles.
`2SO_2 + O_2 overset("Particulates")to 2SO_3`
Discussion
39.

Oxidation of nitrogen monoxide was strudied at 200^@C with initial pressure of 1 atm NO and 1 atm of O_2. At equilibrium partial pressure of oxygen is found to be 0.52 atm. Calculate K_P value.

Answer»

SOLUTION :`2NO(g) + O_2(g) hArr 2NO_2(g)`

`[O_2]` at equilibrium `RARR 1 - x = 0.52`
` x = 0.48`
So, `P_(NO) = 1-2x = 1 - 2(0.48) = 0.04`
`P_(O_2) = 0.52`
`P_(NO_2) = 2x= 2(0.48) = 0.96`
`K_P ((P_(NO_2)))/((P_(NO)^2)(P_(O_2)))=(0.96 XX 0.96)/(0.04 xx 0.04 xx 0.52)`
`K_P = 1.107 xx 10^3`
Discussion
40.

Oxidation of nitrogen monoxide was studied at 200^(@)C with initial pressures of 1 atm NO and 1 atm of O_(2). At equilibrium partial pressure of oxygen is found to be 0.52 atm calculate K_(P) value.

Answer»

<P>

Solution :`2NO(G)+O_(2)(g)hArr2NO_(2)(g)`

`K_(P)=((P_(NO_(2))^(2)))/((P_(NO))^(2)(P_(O)))=(0.96xx0.96)/(0.04xx.0.04xx0.52)`
`K_(P)=1.017xx10^(3)`
Discussion
41.

Oxidation of methyl phenyl ketone with conc. HNO_(3) gives

Answer»


`CH_(3)COOH` only

Solution :Oxidation of methyl phenyl KETONE with conc. `HNO_(3)` gives a mixture of benzoic acid and acetic acid having less number of CARBON atoms as compared to PARENT ketone.
Discussion
42.

Oxidation of cyclopentanol to cyclopentanone can be accomplished by using

Answer»

TOLLEN's reagent
chromic acid
bromine water
Fehling's solution

Answer :B
Discussion
43.

Oxidation of C_(6)H_(5)CH_(2)Cl with alk, KMnO_(4) gives_____

Answer»

`C_(6)H_(3)CHO`
`C_(6)H_(5)COOH`
`C_(6)H_(5)CH_(2)OH`
`C_(6)H_(5)CH_(3)`

Solution :`C_(6)H_(5)COOH`
Discussion
44.

Oxidation of base at anode is given by the chemical equation :4OH^(-)toO_(2)+2H_(2)O+4e^(-)What is the equivalent weight of water?

Answer»

Solution :4moles of electrons =2 moles of WATER
2Faradays = 1mole of water
Equivalent weight `=("molecular weight")/("number of FARADAYS")=(18)/(2)=9`
Discussion
45.

Oxidation of an alkene X gives a diol , further oxidation gives a diketone. Which one of the following could be X ?

Answer»

`(CH_3)_2C=C(CH_3)_2`
`CH_3CH=C(CH_3)_2`
`(CH_3)_2CHCH=CH_2`
`C_6H_5CH=CHC_6H_5`

SOLUTION :SINCE the diol on further oxidation forms a diketone , therefore, the diol must be monosubstituted, i.e., it must contain `2^@` alcoholic groups. Therefore, option (d) is correct.
`UNDERSET"(X)"(C_6H_5CH=CHC_6H_5)underset"(BAEYER's reagent)"overset("Cold. aq. ALK." KMnO_4) to underset(("Diol contains two " 2^@ "alcoholic groups"))(C_6H_5-underset(OH)underset|CH-underset(OH)underset|CH-C_6H_5)overset"[O]"to underset"Diketone"(C_6H_5-undersetundersetO(||)C-undersetundersetO(||)C-C_6H_5)`
Discussion
46.

Oxidation number of Sodium in Sodium amalgam

Answer»

`+2`
`+1`
`-2`
`+3`

ANSWER :D
Discussion
47.

Oxidation of alkenes by cleavage with acidic or alkaline KMnO_4 or acidic K_2Cr_2O_7 at higher temperature yields products depending upon the nature of alkene. A hot solution of is a strong oxidizing agent which gives only ketones and carboxylic acids and not aldehydes (as they cannot be isolated) Which of the these compounds on treatment with OsO_4 followed by Na_2SO_3 will give Cis-2-methylbutane-2,3-diol?

Answer»

2-Methyl-2-butene
4-methyl-2-pentene
2,3-Dimethyl-2-butene
2,2-Dimethyl-2-butene

SOLUTION :2-Methyl-2-butene
Discussion
48.

Oxidation of alkenes by cleavage with acidic or alkaline KMnO_4 or acidic K_2Cr_2O_7 at higher temperature yields products depending upon the nature of alkene. A hot solution of is a strong oxidizing agent which gives only ketones and carboxylic acids and not aldehydes (as they cannot be isolated) Which of these compounds on oxidation with hot KMnOą gives only butanoic acid?

Answer»

Oct-3-ene
Oct-4-ene
Oct-2-ene
3-methylhept-3-ene

Solution :Oct-4-ene
Discussion
49.

Oxidation of acetaldehyde with selenium dioxide produces

Answer»

Ethanoic acid
Glyoxal
Oxalic acid
Methanoic acid

Solution :`CH_(3)CHO + SeO_(2) RARR UNDERSET("Glyoxal")(OHC - CHO) + Se + H_(2)O`
Discussion
50.

Oxidation numbers of the metal in the minerals haematite and magneetite respectively are:

Answer»

II,III in haematite and III in magnetite
II, III in haematite and II in magnetite
IIinhaematitie and II,III in magnetite
III in haematitie and II, III in magnetitie

Solution :In haematite `(Fe_(2)O_(3))`, oxidation NUMBER of
Fe:2x+3(-2)=0,x=+3
In magnetitte `(Fe_(3)O_(4))` is a mixed oxide of FEO and `Fe_(2)O_(3)`
In FeO,the oxidation number of Fe: x-2=0 orx=+2
In `Fe_(2)O_(3)`O,the oxidation number of Fe: 2x+3(-2) =0 or x=+3
Discussion