Explore topic-wise InterviewSolutions in Current Affairs.

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1.

MnO_(4)^(-) is a good oxidising agent in different mediums changing to MnO_(4)^(-)toMn^(2+) toMnO_(4)^(2-) toMnO_(2) toMn_(2)O_(3) Changes in oxidation number respectively are

Answer»

1,3,4,5
5,4,3,2
5,1,3,4
2,6,4,3

Answer :C
Discussion
2.

MnO_(4)^(-) ions are reduced in acidic condition to Mn^(2+) ions whereas they are reduced in neutral condition to MnO_(2). The oxidation of 25 mL of a solution X containing Fe^(2+) ions required in acidic condition, 20 mL of a solution Y containing MnO_(4)^(-) ions. What volume of solution Y would be required to oxidise 25 mL of solution X containing Fe^(2+) ions in neutral condition ?

Answer»

11.4 mL
12 mL
33.3 mL
35 mL

Solution :`MnO_(4)^(-)+5Fe^(2+)+8H^(+) to Mn^(2+)+5Fe^(3+)+4H_(2)O`
`(M_(1)V_(1))/(1)=(M_(2)V_(2))/(5)`
`(M_(1)xx20)/(1)=(M_(2)xx25)/(5)`
`M_(1)=(M_(2))/(4)`
Neutral MEDIUM
`MnO_(4)^(-)+3Fe^(2+) +4H^(+) to MnO_(2)+3Fe^(3+)+2H_(2)O`
`(M_(1)V_(1))/(1)=(M_(2)V_(2))/(3)`
`((M_(2))/(4))xxV_(1)=(M_(2)xx25)/(3)`
`V_(1)=33.3 mL`
Discussion
3.

MnO_(4)^(-) ions are areduced in acidic condition to Mn^(2+) ions where they are reduced in neutral conditointo MnO_(2) the oxidation of 25 ml of a solutoin x containing Fe^(2) ions requred in acidic condition 20 ml ofa soluton y containg MnO_(4)^(-) ions what volume of solution Y would be required to oxidise 25 ml of solution x containing Fe^(2+) ions in neutral condition ?

Answer»

11.4 ml
12.0 ml
33.3 ml
35.0 ml

Solution :Redox EQUATION for OXIDATION of `Fe^(2+)` ions in ACIDIC and neutral media respectviely are
`MnO_(4)^(-)+8H^(+)+5Fe^(2+)rarrMn^(2+)+5Fe^(3+)+4H_(2)O`
`MnO_(4)^(-)+2H_(2)O+3Fe^(2)rarrMnbO_(2)+3Fe^(3+)+4OH`
since under acidic condition 1 mole of `MnO_(4)^(-)` OXIDISES 5 moles of `Fe^(2+)` ions but only 3 moles under neutral CONDITIONS therefore volume of `MnO_(4)^(-)` used oxidation of 25 ml of same `Fe^(2+)` solution under neutral condition
`(20xx5)/(3)=33.3mL`
Discussion
4.

MnO_(4)^(-2) undergoes disproportionation reaction in acidic medium but MnO_(4)^(-) does not. Give reason.

Answer»

Solution :In `MnO_(4)^(-2)` oxidation number MN is +6 but its increases +7 or DECREASES +4, +3, +2, 0. So this type of reaction is known as disproportionation reaction.

In `MnO_(4)^(-)` oxidation number of Mn is +7 which CONTAINS less oxidation number than +7. So `MnO_(4)^(-)` not acts as disproportionation reaction.
Discussion
5.

MnO_(2) on reaction with conc. HCl liberates chlorine, the liberated chlorine ontreatment with aqueous KI gives iodine. The iodine is neutralized by 40 of 0.1 N hypo solution. The reaction is : 2Na_(2)S_(2)O_(3)+I_(2) to 2NaI+Na_(2)S_(4)O_(6) The amount of MnO_(2) used in the reaction is :

Answer»

10 G
0.174 g
1.74 g
0.0174 g

Answer :B
Discussion
6.

MnO_(2) + KOH + O_(2) rarr K_(2)MnO_(4) + H_(2)O. Give the stoichiometric coefficient of reactants and products respectively.

Answer»

2, 4, 1, 2, 1
2, 4, 1, 2, 2
2, 4, 2, 1, 2
2, 4, 2, 2, 2

Answer :A::B::D
Discussion
7.

…….ml (volume ) is required of or 10 volume H_2O_2 of 2N KMnO_4 in acidic medium ?

Answer»

200 ML
100 ml
224 ml
150 ml

Solution :`N=V/5.6=10/5.6`= 1.7857 N `H_2O_2`
`N_1V_1(H_2O_2) = N_2V_2(KMnO_4)`
`V_1=(2xx200)/1.7857`=224 ml of `H_2O_2`
Discussion
8.

Mixture x= 0.02 mol of [Co(NH_(3))_(5)SO_(4)]Br and0.02 mole of [Co(NH_(3))_(5)Br]SO_(4) was prepared in 2 L of solution. 1 litre of mixture x+ excess of AgNO_(3) rarr y 1 litre of mixture x +excess of BaCl_(2) rarr z Number of moles of yand z are ...

Answer»

0.01, 0.01
0.02, 0.01
0.01, 0.02
0.02, 0.02

Answer :A
Discussion
9.

Mixture of nitrobenzene and aniline can be separated by

Answer»

Distillation
Crystallisation
Steam distillation
Both (1) and (3)

SOLUTION :NITROBENZENE and aniline are PURIFIED by steam distillation.
Discussion
10.

Mixture of MgCl_2 and Mgo is called

Answer»

PORTLAND CEMENT
Sorel's cement
double salt
none of these

Solution :Sorel.s cement
Discussion
11.

Mixture of lime stone end clay when heated forms

Answer»

Hydraclic MORAL
Moltal
Cement mortal
All

Answer :1
Discussion
12.

Mixture of Con. HCl and anhydrous ZnCl_(2) is called____

Answer»

BAYER's REAGENT
LUCAS reagent
Grignard reagents
Tollens reagents

Solution :Lucas reagent
Discussion
13.

Mixture of calcium carbonate and magnesium carbonate are used as flux in isolation of ....... metals.

Answer»

Steel
Copper
Iron
Zinc

Answer :C
Discussion
14.

Mixture of ....... and plaster of paris, which on setting become hard and known as kiln cement.

Answer»

Borex
Potash alum
Sodalime
Gypsum

Answer :B
Discussion
15.

Mixture of 1 mole BaF_(2) and 2 mole H_(2)SO_(4) can not be neutralised by :

Answer»

2 MOLE `Ba(OH)_(2)`
2 mole `CA(OH)_(2)`
4 mole NaOH
2 mole KOH

Solution :N//A
Discussion
16.

Mixture 'a' may contain: (P) PbCI_(2) (Q) AgCI (R) Hg_(2)CI_(2)

Answer»

Only P
Q and R
Only R
P, Q and R

Answer :D
Discussion
17.

Mixing of solutions of BaCl_(2) and Na_(2)SO_(4) results in the formation of a precipitate of BaSO_(4) only if.......greater than..........

Answer»


ANSWER :IONIC PRODUCT, SOLUBILITY product
Discussion
18.

Mixing of two gases by diffusion is

Answer»

REVERSIBLE 
irreversible 
Exothermic 
endothermic 

SOLUTION :Gases from HOMOGENEOUS mixtures .
Discussion
19.

Mixing of N_(2) and H_(2) form an ideal gas mixture at roo, temperature in a container.For this process, which of the following statements is true?

Answer»

`DELTAH = 0, DeltaS_("SURROUNDING") =0 , DeltaS_("system") = 0 and DeltaG = -ve`
`DeltaH = 0, DeltaS_("surrounding") = 0 , DeltaS_("system") gt 0 and DeltaG = -ve`
`DeltaH gt 0, DeltaS_("surrounding") = 0 , DeltaS_("system") gt 0 and DeltaG = -ve`
`DeltaH lt 0, DeltaS_("surrounding") gt 0 , DeltaS_("system") lt 0 and DeltaG = -ve`

ANSWER :B
Discussion
20.

Minimum percentage of ethyl alcohol by weight in its aqueous solution, so that gun powder soaked in the aqueous solution catches fire is

Answer»

`95.5%`
`57.1%`
`33.3%`
`49.4%`

SOLUTION :Gun powder SOAKED in under PROOF ALCOHOL DONOT catch fire.
Discussion
21.

Minimum number of physical forms that an element should exist to show allotropy.

Answer»

0
1
2
3

Solution :TWO
Discussion
22.

Minimum number of electrons having m_(s)=(-1/2) in Cr is "_______"

Answer»


ANSWER :9
Discussion
23.

Minimum number of carbon required to exhibit chain isomerism

Answer»

3
4
5
6

Solution :C - C - C - C`C - undersetoverset(|)(C )(C ) - C `
Discussion
24.

The minimum number of carbon atoms to be present in an alkyne to exhibit chain isomerism is

Answer»

3
4
5
6

Solution :`C-C-C-C""C-UNDERSET( C )underset(|)C-C`
Discussion
25.

Minimum de-Broglie wavelength is associated with

Answer»

Electron
proton
`CO_2` molecule
`SO_2` molecule

Solution :`LAMBDA=h/"MV"`.For same velocity `lambda PROP 1/m`
`SO_2` molecule has least WAVELENGTH because their MOLECULAR mass is high.
Discussion
26.

Minimum amount of Ag_(2)CO_(3)(s) required to produce sufficient oxygen for the complete combusion of C_(2)H_(2) which produces 11.35 litre of CO_(2) at STP after combusion is: Ag_(2)CO_(3) (s) rightarrow 2Ag(s) + CO_(2)(g) + (1/2)O_(2)(g), C_(2)H_(2) +(5/2)(O_(2)) rightarrow 2CO_(2) + H_(2)O

Answer»

276g
345g
690g
1380g

Answer :B
Discussion
27.

Minimum carbon atoms required for an alkane to show opticalisomerism.

Answer»


SOLUTION :
Discussion
28.

Minimum amount of energy required to remove a proton is approximately:

Answer»

2MeV
4 MeV
6 MeV
8 MeV

Answer :A
Discussion
29.

Minimum accelerating potential (volts) needed to accelerate an electron to produce a yellow line (lambda= 310 nm) in the spectrum , in an electron tube containing some vapours is :

Answer»

1.2
4
`6.4 xx 10^(-19)`
`2 xx 10^(-15)`

ANSWER :B
Discussion
30.

Mineral of aluminium that does not contasin oxygen is

Answer»

corundum
DIASPORE
bauxite
CRYOLITE

Solution : Cryolite FORMULA is `Na_(3)AlF_(6)`
Discussion
31.

Milk is an example of

Answer»

GEL
Emulsions
sol
Suspension

Solution :Milk is an EMULSION of LIQUID fats in WATER
Discussion
32.

Milk is a colloid in which a

Answer»

Liquid is dispersed in a liquid
Solid is dispersed in a liquid
Gas is dispersed in a liquid
Sugas is dispersed in liquid.

Solution :MILK is an (colloid) emulsion in which liquid FATS are disperesed in WATER, an ANOTHER liquid.
Discussion
33.

Milk is

Answer»

FAT DISPERSED in WATER
fat dispersed in milk
fat dispersed in fat
water dispersed in milk

Solution :Milk is an OIL in water type emulsion.
Discussion
34.

Milk can be preserved by adding a few drops of

Answer»

Formic ACID solution
Formaldehyde solution
Acetic acid solution
Acetaldehyde solution.

Solution :Fomaldehyde kills the micro-organism which SPOILS the milk by producing lactic acid which COAGULATION the milk
Discussion
35.

Milk can be preserved by adding a few drops of:-

Answer»

FORMIC ACID solution
Formaldehyde solution
Acetic acid solution
Acetaldehyde solution

Solution :Milk can be preserved by ADDING a few drops of HCHO solution. HCHO is an emulsifier.
Discussion
36.

Mild oxidation of glycerol with H_(2)O //FeSO_(4) gives

Answer»

GLYCERALDEHYDE
Dihydroxyl acetone
Glycerose
None

Solution :`{:(CH_(2)-OH "" CH_(2)-OH "" CHO),("|""|""|"),(CH-OH underset(FeSO_(4))overset(H_(2)O_(2))RARR " "C=O""+""CH-OH),("|""|""|"),(CH_(2)-OH "" CH_(2)-OH "" CH_(2)-OH),("Dihydroxy acetoneGlyceraldehyde"):}`
The mixture of dehydroxy acetone and glyceraldehyde is known as glycerose.
Discussion
37.

Mild oxidation of bynzyl chloride with Cu(NO_(3))_(2) gives_____

Answer»

BENZOIC acid
Benzene
BENZALDEHYDE
Benzyl alcohol

Solution :benzaldehyde
Discussion
38.

{:("Microcosmic salt"overset(Delta)rarr.,underset(("Transparent"))('M')+H_(2)O+NH_(3)(uarr)),(,""darrCoO),(,'N'("Blue bead")):} Molecular formula of microcosmic salt is:

Answer»

`Na_(2)B_(4)O_(7).10H_(2)O`
`Na_(2)(NH_(4))HPO_(4)`
`Na_(2)(NH_(4))PO_(4).4H_(2)O`
`NA(NH_(4))HPO_(4).4H_(2)O`

Answer :D
Discussion
39.

{:("Microcosmic salt"overset(Delta)rarr.,underset(("Transparent"))('M')+H_(2)O+NH_(3)(uarr)),(,""darrCoO),(,'N'("Blue bead")):} Compound M and N are:

Answer»

`Na_(3)PO_(4)` and `NaCoPO_(4)`
`NaPO_(3)` and `NaCoPO_(4)`
`Na(NH_(4))HPO_(4)` and `Co(PO_(3))_(2)`
`NaPO_(3)` and `Co(PO_(3))_(2)`

Answer :B
Discussion
40.

Microcosmic salt reacts with coloured ions to form characteristic bead which is due to formation

Answer»

Borates
Metaphosphates
Metaborates
Phosphates.

Solution :`underset(("Sod. META phosphae"))(NA(NH_(4))HPO_(4))rarrNaPO_(3)+NH_(3)+H_(2)O`
`NaPO_(3)+CuOrarrNaCuPO_(4)`(Blue mass)
Discussion
41.

Microcosmic salt is

Answer»

`Na(NH_(4)HPO_(4).4H_(2)O`
`Na(NH_(4)).H_(2)O`
`Na(NH_(3))HPO_(4).4H_(2)O`
`K(NH_(4))HPO_(4)`.

SOLUTION :`Na(NH_(4))HPO.4H_(2)O` is called MICROCOSMIC salt
Discussion
42.

Mica is chemically

Answer»

Sheet SILICATE 
CHAIN silicate 
Ortho silicats 
FRAME work silicate 

Answer :A
Discussion
43.

MgSO_(4).7H_(2)Ooverset(150^(@))(to)MgSO_(4).xH_(2)Ooverset(200^(@))(to)MgSO_(4).yH_(2)O

Answer»


Solution :`MgSO_(4)*7H_(2)O OVERSET(150^(@))(to)mgSO_(4)*xH_(2)Ooverset(200^(@))(to)MgSO_(4).yH_(2)O`
`:.(x+y=1+0=1)`
Discussion
44.

MgSO_(4).7H_(2)Ooverset(423k)(to)Aoverset(473k)(to)B Boverset(Delta)(to)C+2SO_(2)+O_(2) Which of the following options are incorrect.

Answer»

`{:(A,B,C),(MgSO_(4)*H_(2)O,MgSO_(4),MgO):}`
`{:(A,B,C),(MgSO_(4),MgO,MgSO_(4)*H_(2)O):}`
`{:(A,B,C),(MgO,MG(OH)_(2),MgCO_(3)):}`
`{:(A,B,C),(Mg(OH)_(2),MgSO_(4),MgSO_(4)*H_(2)O):}`

Solution :`MgSO_(4).7H_(2)Ooverset(423K)underset(-6H_(2)O)(to)underset(A)(MgSO_(4).H_(2)O)overset(473K)(to)`
Discussion
45.

MgSO_(4) on reaction with NH_(4)OH and Na_(2)HPO_(4) forms a white crystalline. What is its formulla?

Answer»

`Mg(NH_(4))PO_(4)`
`Mg_(3)(PO_(4))_(2)`
`MgCl_(2).MgSO_(4)`
`MgSO_(4)`

Solution :A white precipitate of MAGNESIUM AMMONIA phosphate is formed.
`MgSO_(4)+Na_(2)HPO_(4)+NH_(4)OH RARR underset("White ppt.")(Mg(NH_(4))PO_(4)darr +Na_(2)SO_(3)+H_(2)O`
Discussion
46.

MgSO_(4(s)) + H_(2)O rarr MgSO_(4(aq)), Delta H = - 84K. Cals, Delta H of the reaction is known as

Answer»

HEAT of DILUTION
Heat of SOLUTION
Heat of FUSION
Heat of transition

Answer :B
Discussion
47.

Mg(OH)_2 is soluble in NH_4CI, but not in NaCl. Why?

Answer»

Solution :Adding `NH_4 CI` to `Mg(OH)_2`, the interaction takes place to give magnesium chloride and ammonium hydroxide.
`Mg(OH)_2 + 2NH_4 CI toMgCl_2 + 2NH_4 OH `
`NH_4 OH ` being a weak base, reduces the `[OH^(-)]` in solution. Product of `[Mg^(2+)]` and `[OH^(-)]` REMAINS lower than `K_(sp)`of `Mg(OH)_2` to give no precipitation of `Mg(OH)_2` .
Adding NACL to `Mg(OH)_2`, the interaction LEADS to give magnesium chloride and sodium hydroxide.
`Mg(OH)_2 +2NaCl toMgCl_2 + 2NaOH`
NaOH being a strong base produces free `OH^(-)` ions in solution.
Ionic product of `[Mg^(2+)] and [OH^(-) ]` EXCEEDS the solubility product, showing precipitation of magnesium hydroxide
Discussion
48.

MgO has the structureof NaCl and TICl has the structure of CsCl. What are the coordination numbers of the ions in MgO and TiCl ?

Answer»

SOLUTION :6 and 8 RESPECTIVELY.
Discussion
49.

MgO has the structure of NaCl and TICI has the structure of CsCl. What are the coordination mumber of the ions in MgO and TICI ?

Answer»

SOLUTION :6 and 8 respecitvely
Discussion
50.

MgCl_(2).6H_(2)Ocannot be dehydrated on strong heating .Why?

Answer»

Solution :`MgCl_(2).6H_(2)O` has SIX WATER molecules andthe wateris called water of crystallisation .On HEATING it loses found fourwater molecules .
`MgCl_(2).6H_(2)O overset ("heat") toMgCl_(2).2H_(2)O+4H_(2)O`
water in `MgCl_(2).2H_(2)O` is called lattice water .
On heating , lattice water reacts with mahnesium chloride/It UNDERGOES HYDROLYSIS and forms refractory magnesia .
Therefore `MgCl_(2).2H_(2)O` is heated in the presence of dry HCl, to prevent possible hydrolysis.
Discussion