Explore topic-wise InterviewSolutions in Current Affairs.

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1.

Oxidation states of the metal in the minerals 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, III in magnetite
III in haematite and II, III in magnetite

Solution :(i) Haematite is `Fe_(2)O_(3)` in which Fe is present in III OXIDATION state.
(ii) Magnetite `(Fe_(3)O_(4))` is an EQUIMOLAR MIXTURE of FeO and `Fe_(2)O_(3)`.
Oxidation state of Fe in FeO is II.
Oxidation state of Fe in `Fe_(2)O_(3)` is III.
Discussion
2.

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

Answer»

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

Solution :Oxidation state of H is `+1` and that of O is `-2`.
LET the oxidation state of P in the GIVEN compounds is x.
In `H_(4)P_(2)O_(5)`
`(+1)xx4+2xx x+(-2)xx5=0`
`4+2X - 10 = 0`
`2x = 6`
`:. x = +3`
In `H_(4)P_(2)O_(6)`
`(+1) xx4+2xx x + (-2)xx6=0`
`4+2x-12=0`
`2x=8`
`:. x = +4`
In `H_(4)P_(2)O_(7)`
`(+1)xx4+2xx x + (-2)xx7=0`
`4+2x-14=0`
`2x=10`
`:. x = +5`
Thus the oxidation states of `P` in `H_(4)P_(2)O_(5)`. `H_(4)P_(2)O_(6)` and `H_(4)P_(2)O_(7)` are `+3,+4` and `+5` respectively.
Discussion
3.

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»

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

ANSWER :A::C::D
Discussion
4.

Oxidation states of carbon atoms in methane and ethane are :

Answer»

`+ 2, + 4`
`+4,+2`
`-4,4`
ZERO, zero

Answer :D
Discussion
5.

Oxidation state/s exhibited by Ce is / are

Answer»

`+2` only
`+3,+4`
`+4` only
`+2,+3,+4`

ANSWER :B
Discussion
6.

Oxidation state of uranium in UO _(2)^(2+) is

Answer»

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

ANSWER :C
Discussion
7.

Oxidation state of the metal in the minerals 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 ll, III in magnetite
III in haematite andll, III in magnetite

Answer :D
Discussion
8.

Oxidation state of the metal in the minerals 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,III in magnetite
III in haematite and II,III in magnetite

Answer :D
Discussion
9.

Oxidation state of sulphur in H_2 S is

Answer»

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

SOLUTION :`-2`
Discussion
10.

Oxidation state of S in H_(2)SO_(5) and H_(2)S_(2)O_(8) respectively are

Answer»

`+6, +6`
`+6, +4`
`+8, 7`
`+4, +4`

ANSWER :A
Discussion
11.

Oxidation state of S in compound 'Z' is

Answer»

`+1`
`+4`
`+6`
`+2`

ANSWER :B
Discussion
12.

Oxidation state of phosphorus is least in

Answer»

HYPOPHOSPHORIC ACID
Hypophosphorus acid
METAPHOSPHORIC acid
Pyrophosphoric acid

ANSWER :2
Discussion
13.

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

Answer»

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

ANSWER :4
Discussion
14.

Oxidation state of oxygen is + 1 in .......... And +2 in ,.......

Answer»

SOLUTION :`O_2F_2,OF_2`
Discussion
15.

Oxidation state of oxygen in super oxide is

Answer»

O
0.5
1
1.5

Answer :B
Discussion
16.

Oxidation state of oxygen in H_2O_2 IS

Answer»

`-1`
2
S
`-2`

ANSWER :A
Discussion
17.

Oxidation state of oxygen atom in sodium peroxide is :

Answer»

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

ANSWER :B
Discussion
18.

Oxidation state of oxygen atom in potassium superoxide (KO_2) is

Answer»

`1//2`
ZERO
`+1//2`
`-2`

ANSWER :A
Discussion
19.

Oxidation state of nitrogen is incorrectly given for

Answer»

`{:(,"COMPOUND","Oxidation State"),((a),Mg_(3)N_(2),""-3):}`
`{:(,"Compound","Oxidation State"),((b),NH_(2)OH,""-1):}`
`{:(,"Compound","Oxidation State"),((C),(N_(2)H_(5))_(2)SO_(4),""+2):}`
`{:(,"Compound","Oxidation State"),((d),[Co(NH_(3))_(5)Cl]Cl_(2),""-3):}`

Answer :C
Discussion
20.

Oxidation state of nitrogen is not correctly given for the compound

Answer»

`[CO(NH_3)_5Cl]Cl_2`
`NH_2OH(-1)`
`(N_2H_5)_2So_4(-2)`
`Mg_3N_2(-3)`

Answer :A
Discussion
21.

Oxidation state of N in HNO_(3) is ………………….. .

Answer»

`+2`
`+3`
`+4`
`+5`

SOLUTION :`+5`
Discussion
22.

Oxidation state of mercury in amalgams is:

Answer»

ZERO
One
Two
Three

Answer :A
Discussion
23.

Oxidation state of Iron and the charge on the ligand NO in [Fe(H_(2)O)_(5)NO]SO_(4) are …………. .

Answer»

`+2` and `0` respectively
`+3` and `0` respectively
`+3` and `-1` respectively
`+1` and `+1` respectively

Answer :A::C::D
Discussion
24.

Oxidation state of Fe in Fe_(3)O_(4) is

Answer»

`3/2`
`4/5`
`5/4`
`8/3`

Solution :`overset(**)(F)e_(3)O_(4)`
`3X+(-8)=0, 3x-8=0`
`3x=8 implies x=8/3`.
Discussion
25.

Oxidationstate of Fe in compound (F) is

Answer»

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

ANSWER :a
Discussion
26.

Oxidation state of copper is +1 in

Answer»

MALACHITE
cuprite
azurite
chalcopyrite.

Solution :(B,d) : Oxidation state of CU in both cuprite `(Cu_(2)O)` and chalcopyrite `(CuFeS_(2))` is + 1.
Discussion
27.

Oxidation state of cobalt in [Co(NH_(3))_(4)(H_(2)O)Cl]SO_(4) is

Answer»

0
`+4`
`-2`
`+3`

ANSWER :D
Discussion
28.

Oxidation state of chromium is CrO_(5) is

Answer»

`+6`
`+5`
`+3`
`+10`

ANSWER :A
Discussion
29.

Oxidation state of chromium in

Answer»

`+10`
`+6`
`+3`
`+2`

SOLUTION :
`x-6=0"" thereforex=+6`
Discussion
30.

Oxidation state of chlorine is highest the compound :

Answer»

`CI_2`
HCI
`CI_2O`
`CI_2O_7`

ANSWER :D
Discussion
31.

Oxidation state of chlorine in Belacing powder

Answer»

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

ANSWER :D
Discussion
32.

Oxidation state of carbone in its hydrides…………..

Answer»

`+4`
`-4`
`+3`
`+2`

SOLUTION :`CH_(4)^(+)` in which the OXIDATION state of carbon is 4.
Discussion
33.

Oxidation state of carbon in its hydrides

Answer»

`+4`
`-4`
`+3`
`+2`

ANSWER :A::D
Discussion
34.

Oxidation state of +1 for phosphorus is found in:

Answer»

`H_3PO_3`
`H_3PO_4`
`H_3PO_2`
`H_4P_2O_7`

ANSWER :C
Discussion
35.

Oxidation state of +1 for phophorous is found in

Answer»

<P>`H_(3)PO_(3)`
`H_(3)PO_(4)`
`H_(3)PO_(2)`
`H_(4)P_(2)O_(7)`

Answer :3
Discussion
36.

Oxidation state, covalency of sulphur and total number of lone pairs of electrons in S_(8) molecule are respectively

Answer»

`+6,6,16`
ZERO,`2,16`
Zero,`6,12`
`-2,2,16`

ANSWER :B
Discussion
37.

Oxidation state if iron in ferric is

Answer»

`+2`
`+5`
`+3`
`+6`

SOLUTION :It is the correct answer.
Discussion
38.

Oxidation state exhibited by group 13 elements is ___________

Answer»

`+1,+2` and `+3`
`+1` and `+3`
`+1` and `+4`
`+2+3` and `+4`

Answer :B
Discussion
39.

Oxidation products of glucose are

Answer»

Sucrose
glucaric acid
gluconic acid
b' and 'C' both

Answer :D
Discussion
40.

Oxidation product of .X. (molecular formula C_3H_6O is .Y. (molecular formula C_3H_6O_2). The compound .Y. is:

Answer»

ACETIC ACID
FORMIC acid
Propionic acid
Butyric acid

Answer :C
Discussion
41.

Oxidation product 1,2-cyclopentanediol with HIO_(4) gives

Answer»

`Hunderset(O)UNDERSET(||)C-CH_(2)-CH_(2)-CH_(2)-underset(O)underset(||)C-H`

`O= underset(OH)underset(|)C-CH_(2)-CH_(2)-CH_(2)-underset(OH)underset(|)C=O`
NONE of these

Solution :
Discussion
42.

Oxidation potential of given hydrogen half cell at 25^(@)C is 0.118V then what is the pH of H^(+) ion solutioin ? P|underset((1" bar"))(H_(2(g)))|H_((xM))^(+)

Answer»

1
2
3
4

Answer :B
Discussion
43.

Oxidation potential of unimolar calomel electrode is

Answer»

`0.242 V`
`-0.28V`
`-0.33 V`
`-0.43 V`

ANSWER :B
Discussion
44.

Oxidation potential of unimoles of calomel is

Answer»

`+ 0.25` V
`0.00`V
`+0.278 V`
`-0.28V`

SOLUTION :CALOMEL is used as a secondary reference electrode. Since Hg is less reactive than H , its STANDARD REDUCTION potential is positive . Hence , its standard oxidation potential must be negative , ie, `-2.28 V` . [As standard reduction potential = -standard oxidation potential.]
Discussion
45.

Oxidation of which of the following by air in the presence of vanadium pentoxidegivesphenol ?

Answer»

TOLUENE
Benzene
benzaldehyde
PHENYL acetic ACID

ANSWER :B
Discussion
46.

Oxidation oftoluenewith CrO_3 to benzaldehydeis carriedout in thepressureto aceticanhydride

Answer»

SOLUTION :DURINGTHE oxidationoftoluenewith ` CrO_3`as soonasbenzaldehyde is FORMED, itreactswithaceticanhydride to frombenzylinediacetatethischecks thefurtheroxidationof benzaldehydre to BENZOICACID
Discussion
47.

Oxidation of toluene with CrO_(3) in the presence of (CH_(3)CO)_(2)O gives a product 'A' which on treatment with aqueous NaOH produces

Answer»

`C_(6)H_(5)CHO`
`(C_(6)H_(5)CO)_(2)O`
`C_(6)H_(5)COONA`
2,4-diacetyl toluene

Solution :
Discussion
48.

Oxidation of toluene with CrO_(3) in the presence of (CH_(3)CO)_(2)O gives a product 'A' which on treatment with aq. NaOH gives :

Answer»

2, 4- Diacetyl toluene
`C_(6)H_(5)CHO`
BENZOIC abhydride
`C_(6)H_(5)COOC_(2)H_(5)`.

Answer :B
Discussion
49.

Oxidation of toluene to benzaldehyde by chromyl chloride is called

Answer»

Rosenmund reaction
WURTZ reaction
Etard reaction
FITTIG reaction

Answer :C
Discussion
50.

Oxidation of toluene by chromium oxide in acetic anhydride gives

Answer»

BENZALDEHYDE
BENZOIC ACID
BENZOPHENONE
acetophenone

Answer :A
Discussion