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.

The oxidation numbers of the two chlorine atoms in CaOCl_(2) are not the same.

Answer»


ANSWER :T
Discussion
2.

The oxidation numbers of Mn in MnO_(4)^(-) and [Mn(CN)_6]^(3-) are respectively.

Answer»

`+7 and +3`
`+6 and +3`
`+7 and +2`
`+6 and +2`

ANSWER :A
Discussion
3.

The oxidation number that iron does not exhibit in its common compounds or in its elemental state is

Answer»

0
`+1`
`+2`
`+3`

Solution :FE exhibits +3 , +2 in their compounds and in its elements state OXIDATION number is 0.
Discussion
4.

The oxidation number of the suplhur atoms in peroxomonosuplhuric acid (H_(2)SO_(5)) and peroxodisuphuirc acid (H_(2)S_(2)O_(8)) are respectively

Answer»

`+8 and +7`
`+3 and +3`
`+6 and +6`
`+4 and +6`

Solution :`H-O-O-overset(O)overset(||)S underset(O)underset(||)-OH`
peroxomonosulphuric acid
1+2(-)+x+2(-2)+(-2)+1=0or x =+6
`HO-overset(O)overset(||)underset(O)underset(||)S-OH`
peroxodisuplhuric acid
1+1(-2)+x+2(-2)+2(-1)+x+2(-2)+1(-2)+1=0 or x +6
Discussion
5.

The oxidation number of V in Rb_(4)[HV_(10)O_(28)] is

Answer»

`+3`
`+5`
`+7`
`+6`

Answer :B
Discussion
6.

The oxidation number of..V.. in Rb_(4) Na[HV_(10)O_(28)]is

Answer»

`+3`
`+5`
`+7`
`+6`

Solution :`Rb_4Na[HV_(10)O_(28)]implies[HV_(10)O_(28)]^(-5)`
`({:(4Rb^(+)=+4),(NA^(+)=+1),(""BAR""),(""+5),(""ul""):})`
O.s of `V =1 (1)+10(X) +28 (-2)=-5`
`10 x - 55 =-5 implies 10x = 50 implies x = 5`
Discussion
7.

The oxidation number of the underlined element in K_(4) underline(P_(2))O_(7) is "_______________".

Answer»

`+3`
`-5`
`+5`
`+6`

ANSWER :C
Discussion
8.

The oxidation number of sulphur in S_(8),S_(2)F_(32)andH_(2)S respectively are:

Answer»

`0,+1and-2`
`+2,+1 and -2`
`0,+1and+2`
`-2,+1and-2`

SOLUTION :is the CORRECT answer
Discussion
9.

The oxidation number of sulphur in S_(8),S_(2)F_(2),andH_(2)S respectively, are ____

Answer»

0, +1 and -2
`+2,+1and-2`
`0,+1and+2`
`-2,+1and-2`

Solution :`S_(8)` is elemental form `THEREFORE` S = 0
`S_(2)F_(2)rArr2(S)+2(E)=0`
`therefore2(S)+2(-1)=0`
`therefore2S=2" "thereforeS=1`
`H_(2)SrArr2H+S=0`
`therefore2(+1)+S=0" "therefore S=-2`
Discussion
10.

The oxidation number of sulphur in S_(8), S_(2)F_(2) and H_(2)S respectively are:

Answer»

`0,+1` and -2
`+2, +1` and -2
`0, +1 ` and `+ 2`
`- 2, +1` and -2

ANSWER :A
Discussion
11.

The oxidation number of sulphur in S_(8), S_(2)F_(2) and H_(2)S are

Answer»

`0, +1 and +2`
`+2, +1 and -2`
`0, +1 and +2`
`-2, +1 and -2`

ANSWER :A
Discussion
12.

The oxidation number of sulphur in S_(2)O_(8)^(2-)

Answer»

`+7`
`+6`
`+4`
`+5`

ANSWER :B
Discussion
13.

The oxidation number of sulphur in S_(2)O_(7)^(-2) is "______________".

Answer»

`+6`
`-6`
`+7`
`+4`

ANSWER :A
Discussion
14.

The oxidation number of S in Na_(2) S_(4)O_(6)is

Answer»

`+ 2.5`
 ` + 2 and + 3`(TWO S have + 2 and other two have +3)
+ 2 and + 3 (THREE S have + 2 and one S has + 3)
` + 5 and 0` (two S have + 5 and the other two S have 0)

Solution :`Na_(2)S_4O_6:NaO-underset(O)underset(+5||"")overset(O)overset(||)S-overset(0)S-overset(0)S-overset(O)overset(||)underset(O)underset(||+5)S-ONa`
Discussion
15.

The oxidation number of S in S_8, S_2F_2 and H_2S respectively are :

Answer»

`0,+1,-2`
`+2,+1,-2`
`0,+1,+2`
`+2,+1,-2`

ANSWER :A
Discussion
16.

The oxidation number of phosphorus in PO_(4)^(-3) P_(4)O_(10)and P_(2)O_(7)^(4-)is

Answer»

`+3`
`+2`
`-3`
`+5`

SOLUTION :`overset(+5)PO_(4)^(3-),overset(+5)P_4O_(10),overset(+5)(P_(2))O_7^(4-)`
Discussion
17.

The oxidation number ofPt in [Pt(C_2H_4)Cl_3]^(-) is

Answer»

`+1`
`+2`
`+3`
`+4`

SOLUTION :`[Pt (C_(2)H_(4)Cl_3]^(-1)x+0 -3 =-1, x= +4`
Discussion
18.

The oxidation number of Pt in K [PtNH_(3)Cl_(5))will be

Answer»


Solution :`K[PtNH_3Cl_5],+1+x+0 -5 =0 implies x = +4`
Discussion
19.

The oxidation number of phosphorus in sodium hypophosphite is

Answer»

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

ANSWER :C
Discussion
20.

The oxidation number of phosphorus in Ba(H_(2)PO_(2))_(2) is:-

Answer»

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

ANSWER :C
Discussion
21.

The oxidation number of phosphorus in Ba(H_(2)PO_(2)) is ____

Answer»

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

ANSWER :C
Discussion
22.

The oxidation state of phosphorus in Ba(H_(2)PO_(2))_(2) is

Answer»

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

ANSWER :C
Discussion
23.

The oxidation number of phosphorous in Mg_(2)P_2O_(7)is

Answer»

`+5`
`-5`
`+6`
`-7`

SOLUTION :`Mg_2P_2O_7""^(-)O-UNDERSET(""^(-)O)underset(|)overset(O)overset(||)P-O-underset(O^(-))underset(|)overset(O)overset(||)P-O^(-)P=+5`
Discussion
24.

The oxidation number of oxygen in KO_(3),Na_(2)O_(2 respectively are:

Answer»

3,2
1,0
0,1
`-0.33, -1`

ANSWER :D
Discussion
25.

The oxidation number of O in H_2O_2is……

Answer»

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

ANSWER :B
Discussion
26.

The oxidation number of nitrogen in NCI_(3) is

Answer»

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

ANSWER :B
Discussion
27.

K_(4)[Fe(CN)_(6)] is a

Answer»

`+1`
`+2`
`-1`
0

Solution :`K_4["Ni"(CN)_4],+4+x-4=0 ,x =0`
Discussion
28.

The oxidation number of N in NH4^(+) ion is

Answer»

+4
+3
-3
-4

Solution :`NH^(4+)1`
X + 4 =+1
x=+1-4
x= - 3
Discussion
29.

The oxidation number of 'N' in NH_(3) is

Answer»

`+1//3`
0
`-3`
1

Answer :C
Discussion
30.

The oxidation number of .N. in NH_2 OH is

Answer»

`1//3`
0
`-1`
1

Solution :`X+3 +(-2)=0 IMPLIES x = -1`
Discussion
31.

The oxidation number of monoatomic ions is always"____________".

Answer»

zero
an EVEN number
equal to HALF of the IONIC CHARGE
equal to charge of the ions

Answer :D
Discussion
32.

The oxidation number of Mn is +7 in

Answer»

MANGANESE dioxide
manganese chloride
manganese sulphate
potassium permanganate

Answer :D
Discussion
33.

The oxidation number of Mn in the product of alkaline oxidative fusion of MnO_(2) is

Answer»


Solution :The balanced equation is
`4MnO_(2)+2H_(2)O`
THUS O.N of Mnin `KMnO_(4)` is 7
Discussion
34.

The oxidation number of K in K_(2)O,K_(2)O_(2)andKO_(2) respectively is …

Answer»

`+0.5,+4,+1`
`+2,+1,+0.5`
`+1,+1,+1`
`+0.5,+1,+2`

SOLUTION :ALKALI METALS always possess a +1 oxidation state, whereas oxygen present in `K_(2)O` (oxide) is -2, and in `K_(2)O_(2)` (peroxide) is -1 and in `KO_(2)` (superoxide) is `-1/2`.
Discussion
35.

The oxidation number of 'Mn' in potassium permanganate is

Answer»

6
7
5
8

Answer :B
Discussion
36.

The oxidation number of Fe in Fe(CO)_(5) is

Answer»

4
2
10
None of these

Solution :`FE(CO)_(5)`
O.N of Fe zeroas that CO is ZERO
Discussion
37.

The oxidation number of hydrogen in CaH_(2) and NaH are respectively

Answer»

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

ANSWER :A
Discussion
38.

The oxidation number of Fe in Fe_(2) (SO_(4) )_(3) is

Answer»

+2
+3
+1
0

Solution :`Fe_(2)(SO_(4))_(3)`
2x-6 = 0 , 2x = + 6 =GT x = + 3
Discussion
39.

The oxidation number of Fe in brown ring [Fe(H_(2)O_(3))_(5)NO]^(2+) is

Answer»

0
`+1`
`+2`
`+3`

SOLUTION :`+1.` Refer of RAIN Test, page 11/127
Discussion
40.

The oxidation number of each iron atom in Fe_3O_4 is same .

Answer»

SOLUTION :FALSE : It EXISTS as `FeO.Fe_2O_3` having oxidation NUMBER +2 and +3.
Discussion
41.

The oxidation number of Cr is +6 in

Answer»

`FeCr_(2)O_4`
`KCrO_3Cl`
`CrO_3`
`[Cr(OH_4)]^(-)`

Solution :Consider the oxidation state of.Cr. as .X.
B) `KCrO_(3)Cl implies 1 + x +3 (-2)+(-1)=0`
`1 +x -6 -1=0 implies x =6`
c) ` CrO_5 rarr`
`CrO_(5)=Cr(O)(O)_4`
`implies x +(-2) +4(-1)=0`
`implies x-2 -4 =0 implies x -6 =0 implies x +6`
Discussion
42.

The oxidation number of Cr in K_(2)Cr_(2)O_(7) is………

Answer»

+6
+4
-2
+7

Solution :`K_(2)Cr_(2)O_(7)`
2 + 2X-14 = 0
2x-12 = 0
2x = +12
x = +6
Discussion
43.

The oxidation number of Cr is CrO_(5) is

Answer»

`+10`
`+6`
`+4`
`+5`

Answer :B
Discussion
44.

The oxidation number of Cr in K_2 Cr_2O_7 and K_2 CrO_4 are .......

Answer»

`+6,+3`
`+3,+6`
`+3,+6`
`+6,+6`

SOLUTION :`+6 , +6`
Discussion
45.

The oxidation number of carboxylic carbon atom in CH_(3)COOH is

Answer»

+2
+4
+1
+3

Solution :`CH_(3)COOH`
-3 + 3+x-4+1
x-3= 0 =gt x = + 3`
CARBOXYLIC CARBON OXIDATION number = + 3
Discussion
46.

The oxidation number of carbon is zero is

Answer»

HCHO
`CH_2Cl_2`
`C_(6)H_(12)O_6`
`C_(12)H_(22)O_(11)`

Solution :CONSIDER the oxidation state of .c. as .x.
a) `HCHO =1 + x +1 -2 =0 impliesx =0`
b) `CH_(2)Cl_(2)=x+2(1)+2(-1)=0`
`x+2-2=0 implies x = 0`
c) `C_(6)H_(12)O_(6)=6 (x) + 12 (1) +6(-2)=0`
`6x +12 -12 = 0 implies 6x =0 :. x = 0 `
d) `C_(12)H_(22)O_(11)=12(x) +22(1)+11(-2)=0`
`12X +22-22=0 implies x =0`
Discussion
47.

The oxidation number of carbon in Glucose is_______

Answer»


Solution :GLUCOSE = `C_(6)H_(12)O_6`CONSIDER the oxidation NUMBER of carbon as .x.
`C_(6)H_(12)O_(6):6(x)+12(1)+6(-2)=0`
`6x+12-12=0`
`:. X =0`
Discussion
48.

The oxidation number of carbon in CH_(3) - CH_(2)OH is

Answer»

-3
-2
+2
+4

Solution :`C_(2)H_(5)OH`
2x + 6-2 = 0 , 2x + 4 = 0
2x = -4 , X = -2
Discussion
49.

The oxidation number of carbon in CH_2Cl_2 is +4.

Answer»

SOLUTION :FALSE : It is ZERO
Discussion
50.

The oxidation number of carbon is zero in

Answer»

HCHO
`C_(12)H_(22)O_(11)`
`C_(6)H_(12)O_(6)`
all of the above

Answer :D
Discussion