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.

Roasting of copper pyrites is done

Answer»

to remove MOISTURE and VOLATILE impurities
to oxidise FREE sulphur
to DECOMPOSE pyrites into `Cu_2S` and FeS
None of these

Solution :Roasting involves to remove volatile impurites
Discussion
2.

Roasting is used in the extraction of :

Answer»

GALENA
IRON PYRITE
COPPER glance
All

Answer :D
Discussion
3.

Roasting is used during metallurgical operation using

Answer»

Galena
Iron pyrites
Copper glance
All

Answer :D
Discussion
4.

Roasting is used during metallurgical operations for :

Answer»

GALENA
IRON pyrites
Copper GLANCE
All

Answer :D
Discussion
5.

Roasting is generally done in case of the

Answer»

OXIDE ORES
silicate ores
sulphide ores
carbonate ores

SOLUTION :In THISPROCESS sulphide oresareconvettedintooxideores:
` 2ZnS +3O_2 to2ZnO+ 2SO_2 UARR`
Discussion
6.

Roasting is generally done in case of :

Answer»

OXIDE ores
SILICATE ores
SULPHIDE ores
carbonate ores.

Answer :C
Discussion
7.

Roasting is generally done in case of

Answer»

OXIDE ORES
SILICATE ores
sulphide ores
CARBONATE ores

Answer :C
Discussion
8.

Roasting is generally carried out in case of

Answer»

OXIDE ores
Sulphide ores
Silicate ores
Carbonate ores

Answer :B
Discussion
9.

Roasting is generally carried out in case of....

Answer»

SILICATE ORES 
Oxide ores 
CARBONATE ores 
Sulphide ores 

ANSWER :D
Discussion
10.

Roasted silver ore +CN-_((aq))+O_(2) to [X]_((aq))+OH_((aq))^(-),[X]_((aq))+Zn to [Y]_((aq))+Agdarr The [X] and [Y] are respectively :

Answer»

`[Ag(CN)_(2)]^(-),[Zn(CN)_(6)]^(-4)`
`AgCN,[Zn(CN)_(4)]^(-2)`
`[Ag(CN)_(4)]^(-3),[Zn(CN)_(4)]^(-2)`
`[Ag(CN)_(2)]^(-),[Zn(CN)_(4)]^(-2)`

ANSWER :D
Discussion
11.

Roasting is generally carried out in case of :

Answer»

OXIDE ores
Sulphide ores
Silicate ores
Carbonate ores

Answer :B
Discussion
12.

Roasting involves _________.

Answer»

only volatilization of volatile IMPURITIES
volatilization of volatile impurities and decomposition of the ORE
volatilization of volatile impurities and decomposition and oxidation of the ore
oxidation and reduction of the ore and slag formation

Answer :C
Discussion
13.

Roasting is carried out in case of

Answer»

GALENA
IRONPYRITES
COPPER GLANCE
All

Answer :D
Discussion
14.

Roasting.

Answer»

SOLUTION :It is a process of STRONGLY heating a CONCENTRATION ore in the EXCESS of air below melting point of metal, to convert it INOT oxide form. For example, PbS, ZnS ores on roasting form PbO, ZnO respectively.
Discussion
15.

Roasted on one is mixed with coke and time stone and smelted in blast fumice. Whichamong the following does not represent the correct answer about the reactions taking place in the blast fumace.

Answer»

In the lower part, called ZONE of fusion temperature (1773 K) COKE burns to `CO_(2)` producing 97000 calories of beat
In the middle part, limestone decomoses to GIVE `Co_(2)` and lime which acts as a reducing agent.
in the middle part of the furnace called one of heat ABSORPTION (temperture 1073-1273 K) `CO_(2)` is reduced to CO
At the top is the one of reduction temperature (673-973 K). Here iron oxide is reduced to spongy iron by

Answer :B
Discussion
16.

Roasted gold ore +CN^(-)water overset(O_(2))to[X]+OH^(-),[X]+Znto[Y]+Au then the coordination number of metal in [X] is 'a' the coordination number of metal in [Y] is 'b' then 'a+b'is

Answer»


ANSWER :6
Discussion
17.

Roasted gold ore +CN^(-)+H_(2)O overset(O_(2)) to [x]+OH, [x]+Zn to [y]+Au[x] and |y| are

Answer»

`x=[Au (CN)_(2)]^(-) "" y=[Zn(CN)_(4)]^(-2)`
`x=[Au(CN)_(4)]^(-3) "" y=[Zn(CN_(4))]^(-2)`
`x=[Au(CN)_(2)]^(-) "" y=[Zn(CN)_(6)]^(-4)`
`x=[Au(CN)_(4)]^(-3) "" y=[Zn(CN)_(6)]^(-2)`

SOLUTION :`Au_(2)S+4NaCN hArr UNDERSET((x))(2NA[Au(CN)_(2)])+Na_(2)S`
`2Na[Au(CN)_(2)]^(-)+Zn to Na_(2)[Zn(CN)_(4)]+2Au`
`X=[Au(CN)_(2)]^(-) and Y=[Zn(CN)_(4)]^(-2)`
Discussion
18.

Roasted gold ore +CN^(-)+H_(2)O overset(O_(2)) to [X]+OH^(-)

Answer»

`X=[Au(CN)_(2)]^(-) , Y=[Zn(CN)_(4)]^(2-)`
`X=[Au(CN)_(4)]^(3-) , Y=[Zn(CN)_(4)]^(2-)`
`X=[Au(CN)_(2)] , Y=[Zn(CN)_(6)]^(2-)`
`X=[Au(CN)_(4)]^(3-) , Y=[Zn(CN)_(6)]^(4-)`

Solution :`2[Au(CN)_(2)]^(-) (AQ)+Zn(s) to [Zn(CN)_(4)]^(2-)(aq)+2Au(s)`
Discussion
19.

Roasted gold ore +CN^(-)+H_(2)O+ overset(O_(2)) to x+OH^(-),What is the oxidation at 'Au' is complex 'x

Answer»


SOLUTION :`Au_(2)S+4NaCN HARR 2Na[AU(CN)_(2)]+Na_(2)S`
Oxidation state of Au in the compole is +1
Discussion
20.

Roasted copper pyrites on smelting with sand produces_________.

Answer»

`FeSiO_(3)` as FUSIBLE slag and `Cu_(2)O` matte
`CaSiO_(3)` as infusible slag and `Cu_(2)S` matte
`Ca_(3)(PO_(4))_(2)` as fusible slag and `Cu_(2)S` matte
`Fe_(3)(PO_(4))_(2)` as infusible slag and `Cu_(2)S` matte

Answer :A
Discussion
21.

Roasted copper pyrite on smelting with sand produces

Answer»

`FeSiO_3` as fusible SLAG and `Cu_2 S` as matte
`CaSiO_3` as in fusible slag and `Cu_2 O` as matte
`Ca_3 (PO_4)_2` as fusible slag and `Cu_2 S` as matte
`Fe_3 (PO_4)_2` as infusible slag and `Cu_2 S ` as matte

Solution :The roasted COPPER pyrite contain `Cu_2 S` and FeO and some unreacted FeS. On smelting , the roasted copper pyrites with sand give fusible ferros silicate slag, `FeSiO_3` and `Cu_2 S ` as matte.
`FeO + UNDERSET("Silica")(SiO_2) to underset("(slag)")underset("Ferrous silicate")(FeSiO_3)`
Discussion
22.

Roastedcopperpyrite on smeltingwith sandproduces

Answer»

`FeSiO_3 `as fusibleslagand` Cu_2 S `as matte
` CaSiO_3 `as infusibleslagand ` Cu_2O `as matte
` Ca_3 (PO_4)_2 ` as fusibleslagand` Cu_2 S `as matte
` Fe_3 (PO_4)_2 `asinfusible slagand` Cu_2S `as matte

Solution :Duringsmelting , silicacombineswithFeOto formfusible` FeSiO_ 3`slagand` Cu_ 2 S`as matte.
Discussion
23.

RNH_(2) can be converted into R, NH and no other amine by

Answer»

its REACTION with RX
its reaction with `(CH_(3)Cl//KOH, Delta)` followed by reaction
its reaction with `(CHCl_(3)//KOH, Delta)` followed by hydrolysis
all of the above.

Answer :B
Discussion
24.

Roasting of HgS in air produces:

Answer»

HGO
`HgSO_3`
`HgSO_4`
Hg

Answer :D
Discussion
25.

RNA is different from DNA because RNA contains……..

Answer»

RIBOSE SUGAR and tymine
Ribosesugar anduracil
Doxyribosesugar and thymine
Deoxy ribose SUGARAND URACIL

Answer :B
Discussion
26.

RNA is different from DNA< because RNA contains:

Answer»

RIBOSE SUGAR and thymine
ribose sugar and uracil
deoxyribose sugar and uracil
deoxyribose sugar and thymine

Answer :B
Discussion
27.

RNA is different from DNA because RNA contains

Answer»

RIBOSE SUGAR and thiamine
ribose sugar and uracil
deoxyribose sugar and thiamine
deoxyribose sugar and uracil

Answer :B
Discussion
28.

RNA is :

Answer»

Single helix STRAND
DOUBLE helix strand
Triple helix strand
NONE of these.

Answer :A
Discussion
29.

RNA differs from DNA with respect to the following

Answer»

type of BASE UNIT 
type of SUGAR unit 
type of H-bond 
1 and 2 

Answer :D
Discussion
30.

RNA and DNA are chiral molecules, there chirality is due to

Answer»

CHIRAL PHOSPHATE ESTER units
D-sugar components
L-sugar components
Chiral base

Answer :B
Discussion
31.

RNA and DNA are chiral molecules, their chirality is due to

Answer»

CHIRAL bases
chiral PHOSPHATE ESTER units
D-sugar component
L-sugar component

Answer :C
Discussion
32.

RNA and DNA are chiral molecules, their chirality is due to :

Answer»

Chiral bases
Chiral phosphate ester units
D -SUGAR COMPONENT
L - sugar component.

Answer :C
Discussion
33.

RNA and DNA are chiral molecules , their chirality

Answer»

D-sugar component
L-sugar componet
chiral bases
chiral PHOSPHATE ESTER UNIT

Solution :D-sugar component is OPTICALLY active due to the presence of chiral carbons.
Discussion
34.

RMgBr on reaction with an excess of oxygen followed by hydrolysis gives

Answer»

RH
ROOR
ROOH
ROH

Solution :
Discussion
35.

RMgX on reaction with O_2 followed by hydrolysis gives :

Answer»

RH
RCOOH
ROR
ROH

Answer :D
Discussion
36.

RMgX on reacting with cyanogen chloride gives :

Answer»

R -NC
R-Cl
R- CN
None

ANSWER :C
Discussion
37.

R=k[O_3]^2

Answer»

`R=k[O_3]^2[O_2]^(-1)`
`R=k[O_3]^2[O_2]^-1`
`R=k[O_3][O_2]`
NONE of these

Answer :B
Discussion
38.

Rio Tinto process is used for extraction of:

Answer»

Cu
Ag
Al
Au

Answer :A
Discussion
39.

Ring test is performed for :

Answer»

`NO_3^(-)` ION
`CO_3^(2-)` ion
`SO_3^(2-)` ion
`PO_4^(3-)` ion.

ANSWER :A
Discussion
40.

Ring test formiratesconformed byacidifyingprepared FeSO_(4) soin a brownring isformedthatto theformation of [Fe(H_(2)O)_(3)NO[SO_(4) Thisrest shouldnot be performed fornitrate ion in presence of

Answer»

`NO_(2)^(THETA)`
`BI^(Theta)`
`I^(Theta)`
All

Answer :d
Discussion
41.

Rinman.s green is :

Answer»

ZnO.CoO
A green pigment
Both (a) and (B)
NONE

ANSWER :C
Discussion
42.

Ring structure of glucose is due to formation of hemiacetal and ring formation is in between

Answer»

`C_1 and C_5`
`C_1 and C_4`
`C_1 and C_3`
`C_2 and C_4`

ANSWER :A
Discussion
43.

Ring-opening reactions of epoxides can proceed by either S_(N)2 or S_(N)1 mechanisms, depending on the nature of the epoxide and on the reaction conditions. If the epoxide is asymmetric, the structure of the product will very according to which mechanisms dominates. When an symmetric epoxide undergoes solvolysis in basic methanol, ring-opening occurs by and S_(N)2 mechanisms, and the less subsitution carbon is the site of nucleophilic attack. Conversely, when solvolysis occurs in acidic methanol, the reaction occurs by a mechanisms with substantial S_(N)1 character, and the more substituted carbon is the site of attack. These are both good examples of regioselective reactions, examine the basic, S_(N)2 case first. The leaving group is an alkoxide anion, because there i s not acid avaialble to protonate the oxygen prior to ring opening. An alkoxide is a poor leaving group, and thus the ring is unlikely to open without a'push' from the nucleophile. Like in other S_(N)2 reactions, nucleophilic attack takes place from the backside, resulting in inversion t the electrophilic carbon. The best way to depict the acid-catalyzed epoxide ring-opening reaction is as a hybrid, or cross, between an S_(N)2 and S_(N)1 mechanism. First, the oxygen is protonated, creatinga good leaving group. Then the carbon-oxygen bond begins to break and positive charge begins to build up on the more substituted carbon. answer the following based on the above : The product formed after nucleophilic attack and mild hydrolysis is

Answer»




ANSWER :A
Discussion
44.

Ring-opening reactions of epoxides can proceed by either S_(N)2 or S_(N)1 mechanisms, depending on the nature of the epoxide and on the reaction conditions. If the epoxide is asymmetric, the structure of the product will very according to which mechanisms dominates. When an symmetric epoxide undergoes solvolysis in basic methanol, ring-opening occurs by and S_(N)2 mechanisms, and the less subsitution carbon is the site of nucleophilic attack. Conversely, when solvolysis occurs in acidic methanol, the reaction occurs by a mechanisms with substantial S_(N)1 character, and the more substituted carbon is the site of attack. These are both good examples of regioselective reactions, examine the basic, S_(N)2 case first. The leaving group is an alkoxide anion, because there i s not acid avaialble to protonate the oxygen prior to ring opening. An alkoxide is a poor leaving group, and thus the ring is unlikely to open without a'push' from the nucleophile. Like in other S_(N)2 reactions, nucleophilic attack takes place from the backside, resulting in inversion t the electrophilic carbon. The best way to depict the acid-catalyzed epoxide ring-opening reaction is as a hybrid, or cross, between an S_(N)2 and S_(N)1 mechanism. First, the oxygen is protonated, creatinga good leaving group. Then the carbon-oxygen bond begins to break and positive charge begins to build up on the more substituted carbon. answer the following based on the above :

Answer»




ANSWER :A
Discussion
45.

Ring structure of glucose is due to formation of hemiacetal and ring formation between :

Answer»

`C_1` and `C_5`
`C_1` and `C_4`
`C_1` and `C_3`
`C_3` and `C_4`

ANSWER :A
Discussion
46.

rignard reagent is used to prepare carboxylic acids. What is the other reagent in this reaction ?

Answer»

SOLUTION :CARBON DIOXIDE
Discussion
47.

Riddish brown gas is obtain with the following are treated with cone H_(2)SO_(4)

Answer»

`BR^(Θ)`
`NO_(2)^(Θ)`
`NO_(3)^(Θ)`
`SO_(3)^(2-)`

Solution :`Br^(Theta)` IONS gives `Br_(2),NO_(2)^(Theta)` and `NO_(3)^(Theta)` GIVE `NO_(2)` gaswichare brown in colour
Discussion
48.

Rickets and Xerophthalmia are caused due to which two deficiencies ?

Answer»


ANSWER :RICKETS is DUE to the DEFICIENCY of vitamin-D, XEROPHTHALMIA is due to the deficiency of vitamin-D.
Discussion
49.

Rickets may be caused by the deficiency of which vitamin ?

Answer»

VITAMIN D
Vitamin C
Vitamin A
Vitamin B

Answer :A
Discussion
50.

Rickets is caused due to the deficiency of

Answer»

Vit-A
vit-B
vit-C
Vit-D

Answer :D
Discussion