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 reagent used for getting trans alkene from alkyl substituted acetylene with hydrogen is

Answer»

Na in liq. `NH_(3)`
LI in liq. `NH_(3)`
Both (1) and (2)
`H_(2)//NI` (or) Pt (or) Pd

Answer :C
Discussion
2.

Which of the following are not state functions ? (I)q+ w ,(II) q, (III) w, (IV) H-TS

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(I) and (IV)
(II), (III) and (IV)
(I),(II) and (III)
(II) and (III)

Solution :`q+w= DeltaU` and`DeltaU` is a STATE FUNCTION `=H-TS = G `and G is a state function.
Discussion
3.

Which multiple bond present in CO_(2), C_(2)H_(4), N_(2) and C_(2) H_(2) ? Draw Lewis and simple bond structure of these molecules.

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Solution :(a) Carbon dioxide (CO2) : In CO2 molecule two double bond present. Electron pair (four electron ) between C and O ATOM.

Between C & O two `e^(-)` pair
(b) Ethene `(C_(2)H_(4))` : In its one double bond (C = C) between two carbon and four single C - H bond. In this between two carbonatoms two electron pairs means four electrons are there so double bond is form.

(c) Dlnitrogen: `(N_(2)) `
(d) Ethyne `(C_(2)H_(2))` :In this one triple bond between two carbon and two C -H single bond. ln this between two carbon three carbon pairs (slx electrons) from three covalent lent bond.

LEWIS and simple REPRESENTATION of bonds in Ethyne
Discussion
4.

What is the mass per cent of carbon in carbon dioxide ?

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`0.034%`
`27.27%`
`3.4%`
`28.7%`

Solution :Molecular mass of `CO_(2) = 1 xx 12 + 2 xx 16= 44g`
1 g molecule of `CO_(2)` contains 1 g atoms of CARBON
`:. ` 44 g of `CO_(2)` contains `C= 12g` atoms of carbon
`:. ` % of C in `CO_(2) = (12)/(44) xx100 = 27.27%`
Discussion
5.

What change observe when dihydrogen and dinitrogen taken in closed vessel ? Give its diagram.

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SOLUTION :
Discussion
6.

Which of the following have Identfical bond order ?

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`CN^(-)`
`NO^(+)`
`O_(2)^(-)`
`O_(2)^(2-)`

ANSWER :A::B
Discussion
7.

Which of the following statements regarding IV A group elements is // are correct.

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They all form tetrahalides
All tetrahalides are not COVALENT
All tetrahalides are tetrahedral
`SiF_(4)` is readily hydrolysed by alkali

SOLUTION :B) All tetrahalides are covalent
C ) Due to `sp^(3)` hybridisation
D) `SiF_(4)+ OH^(-) rarr SiO_(4)^(4-) + 4F^(-) + 4H_(2)O`
Discussion
8.

What are electrophiles and nucleophiles? Give suitable examples for each.

Answer»

Solution :Electrophiles : Electrophiles are reagents that are attracted towards negative charge or electron rich CENTER. They are either positively charged ions or electron deficient neutral MOLECULES.EXAMPLE , `CO_(2)`, `AICI_(3)`, `BF_(3)`,`FeCI_(3)`, `NO^(+)`, `NO_(2)^(+)`, etc.
Nucleophiles : Nucleophiles are reagents thathas high affinity for electropositive centers.They possess an ATOM has a unshared pair of electrons.They are usually negatively charged ions or electron rich neutral molecules.
Example . `NH_(3)`, `R-NH_(2)`, `R-SH`,`H_(2)O`, `R-OH`,`CN^(-)`,`OH^(-)` etc.
Discussion
9.

When a solid melts there is

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An increase in enthalpy
A DECREASE in enthalpy
No CHANGE in enthalpy
A decrease in INTERNAL energy

Solution :`s rarr L rArr Delta H gt 0`
Discussion
10.

Which of the following species in pairs have same shape and same bond order? N_(3)^(-) , NO_(2)^(-) , CO_(2) ,and O_3

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Solution :Isoelectronic species possess same shape and same bond order.
`CO_(2)` and `N_(3)^(-)` are isolectronic (22 electrons)
SIMILARLY `NO_(2)^(-)` and `O_(3)` are isoelectronic (24 electrons).
Thus `CO_(2)` and `N_(3)^(-)` have same shape andbond order. Similarly `NO_(2)^(-)` and `O_(3)` have same shape and bond order.
Discussion
11.

What is vapour pressure of a liquid? What is relative lowering of vapour pressure?

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Solution :(i) The pressure of the vapour in equilibrium with its liquid is called vapour pressure of the liquid at the given temperature.
(II) The relative lowering of vapour pressure is DEFINED as the RATIO of lowering of vapour pressure to vapour pressure of PURE solvent.
Relative lowering of vapour pressure`= (P_("solvent")^@-P_("solution"))/(P_"solvent"^@)`
Discussion
12.

What alkyne would you start with and what reagents would you use to prepare: (i) cis-but-2-ene (ii) trans-pent-2-ene

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SOLUTION :
Discussion
13.

Which hybird orbitals are used by carbon atoms in the following molecules?CH_3-CHO

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SOLUTION :
Discussion
14.

Which one is not a borane ?

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`B_5 H_9`
`B_5 H_(10)`
`B_5 H_(11)`
`B_6 H_(10)`

SOLUTION :`B_5 H_(10)`
Discussion
15.

Which metal is used in formation of armor plate ?

Answer»

CS
RB
K
LI and Ba

Answer :D
Discussion
16.

what happens when dihydrogen reacts with dinitrogen ?

Answer»
Discussion
17.

Which of the following is true in respect of its adsorption ?

Answer»

`DELTAG gt 0, DELTAS gt 0, DELTAH LT0`
`DeltaG lt 0, DeltaS lt 0, DeltaH lt0`
`DeltaG gt 0, DeltaS gt 0, DeltaH lt0`
`DeltaG lt 0, DeltaS lt 0, DeltaH gt0`

Answer :B
Discussion
18.

Which is a homogeneous equilibrium of the following ?

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`NH_4HS_((s)) HARR NH_(3(G)) + H_2S_((g))`
`H_2O_((s)) hArr H_2O_((l))`
`SO_(2(g)) + 1/2O_(2(g)) hArr SO_(3(g))`
`H_2O_((l))hArr H_2O_((s))`

Answer :C
Discussion
19.

Which one of the following has strongest acidic character?

Answer»

HCOOH
`CH_(3)COOH`
`CH_(2)CICOOH`
`C CI_(3)COOH`

Answer :D
Discussion
20.

Which of the following is/are the hazardous pollutant(s) present in automobile exhaust gases? (i) N2 (ii) CO (iii) CH_4 (iv) Oxides of nitrogen

Answer»

(ii) and (III)
(i) and (ii)
(ii) and (IV)
(i) and (iii)

Solution :CO and oxides of nitrogen are POISONOUS gases present in automobile EXHAUST gases.
Discussion
21.

What is molarity of a solution obtained after mixing of 750 mL 0.5 M HCl and mL 2 M HCl ?

Answer»

0.875M
`1.00` M
1.75 M
0.975 M

Solution :`{:(M_(1)=0.5M,M_(2)=2M,M_(3)=?,),(V_(1)=750 ML,V_(2)mL,V_(3)=(750+250)=1000 mL,),(,,,):}`
`M_(3) = (M_(1)V_(1)+M_(2)V_(2))/(V_(3))`
`=((0.5xx750)+(2xx250))/(1000)`
`=(375+500)/(1000) = (875)/(1000) = 0.875M`
Discussion
22.

Visible range of hydrogen spectrum will contain the following series

Answer»

Pfund
Lyman
Balmer
Brackett

Answer :C
Discussion
23.

Which statement is true of 1,3-dimethylcyclobutane?

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Only one FORM of the compound is possible
TWO diastereomeric forms are possible
Two sets of ENANTIOMERS are possible
Two enantiomeric forms and one meso compound are possible

Solution :Two diastereomeric forms are possible
Discussion
24.

Two electrons in the same orbital has antiparallel spin.

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ANSWER :T
Discussion
25.

Which of the following statements is true about the variation of density of elements in the periodic table?

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In a period from LEFT to right DENSITY first increases upto the middle and then starts decreasing
In a group on moving down the density decreases from top to bottom.
A less closely packed SOLID has higher density.
Density of elements is not a PERIODIC property.

Answer :A
Discussion
26.

Which of the following statements regarding sulphur is incorrect ?

Answer»

`S_2` molecule is paramagnetic.
The VAPOUR at `200^@C` CONSISTS mostly of `S_8` rings.
At `600^@C` the gas mainly consists of `S_2` molecules.
The oxidation state of sulphur is never less than +4 in its compounds.

Solution :Sulphur exhibits -2, +2, +4, +6 oxidation states but +4 and +6 are more common.
Discussion
27.

To change the P^(H) of a solution from I to 1.301. Which of the following should be adopted?

Answer»

1 lit of WATER is to be added
1 kg of water is to be added
The volume of the SOLUTION should be doubled by ADDING water
The wt of the solute PRESENT in the solution should be doubled

Solution :New pH = old `pH +log ""( V_2)/( V_1) `
` 1.301 =1 + log"" (V_2)/(V_1) rArr V_2 =2V_1`
Discussion
28.

Which method is used for ionic redox reactions ?

Answer»

IONIC method
Ion-ELECTRON method
Proton - Electron method
Oxidation NUMBER method

Answer :C::D
Discussion
29.

Write IUPAC name of chloral

Answer»

4, 4, 2-Trimethylpentane
2, 2-Dimethylpentane
2, 2-Dimethylbatane
2, 2 4-Trimethylpentane

Answer :D
Discussion
30.

The reactor used to convert stable form to fissile form is

Answer»

Chemical reactor
Nuclear reactor
Breeder reactor
Atomic reactor

Solution :The reactor USED to CONVERT stable NUCLEI into fissionable material is CALLED Breeder reactor.
Discussion
31.

Which of the following is not a metalloid (or) semi-metal?

Answer»

Silicon
Arsenic
Germanium
Sodium

ANSWER :D
Discussion
32.

What are particulate pollutants? Explain any three

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Solution :(i) Particulate pollutans are small solid particles, and liquid drples suspended in air . Examples : dust, pollen, smoke , sood and liquid aerosols.
(ii) Types of Particulates : Particulates in the atmosphere may be of two type: (i) viable particulate and (ii) non-viable particulate.
(iii) The viable particulates are small size living ORGANISMS such as bacteria,fungi, mouldsand algae which are dispersed in air.
(iv) The non-viable particulates are small solid particles and liquid droplets suspended in air. There are four types of non-viable particulates in the atmosphere. They are (a) Smoke (b) Dust (c) Mist (d) Fumes
(v) Smoke: Smoke particulate consists of solid particles formed by combustion of organic matter. For EXAMPLE, cigarette smoke, oil smoke, smokes from burming of fossil fuels, garbage and dry leaves.
(vi) Dust: It is composed of FINE solid particles produced during crushing and grinding of solid materials. For example, sand from sand blasting, saw dust from wood works and fiy ASH from power generating UNITS.
(vii) Mist: They are formed by particles of sprayed liquids and condensation of vapours in air For example, sulphuric acid mist, herbicides and insecticides sprays can form mists.
(viii) Fumes: They are obtained by condensation of vapours released during sublimation, distillation, boiling and calcination and by several other chemical reactions. For example, organic solvents, metals and metallic oxides.
Discussion
33.

Which of the following are all radioactive elements.

Answer»

TRANSITION ELEMENTS.
P BLOCK elements
Lathanides.
Actinides.

Answer :D
Discussion
34.

Which of the following represents physical equilibrium ?

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`PCl_(5) (G) hArr PCl_(3) (g) + Cl_(2) (g)`
`H_(2) (g) + I_(2) (g) hArr 2 HI (g)`
`H_(2) O (I) hArr H_(2) O (g)`
`N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g)`

Solution :Physical states are in equilibrium i.e., LIQUID- VAPOUR equilibrium.
Discussion
35.

Which reactants are used to prepared cis and trans alkenes from alkynes ?

Answer»

Solution :(i) For making cis-alkene Lindlar catalyst (PARTIALLY INERT PALLADIUM charcoal) Pd/C, in PRESENCE of hydrogen.
(ii) for making trans alkene, alkyne is treated with `H_(2)` in presence of LIQUID `NH_(3)` with Na metals.
Discussion
36.

When r, p and M represent rate of diffusion, pressure and molecular mass, respectively, then the ratio of the rates of diffusion (r_A r_B) of two gases A and B, is given by?

Answer»

`(P_A//P_B)^(1//2) (M_A/M_B)`
`(P_A//P_B) (M_B//M_A)^(1//2)`
`(P_A//P_B)^(1//2) (M_B/M_A)`
`(P_A//P_B) (M_A//M_B)^(1//2)`

SOLUTION :`(P_A//P_B) (M_B//M_A)^(1//2)`
Discussion
37.

What would be the formula of the compound formed by A and B, where A has the valence 3 and B has the valence 3?

Answer»

AB
`AB_(3)`
`A_(3)B`
`3AB_(3)`

ANSWER :a
Discussion
38.

Which one of the following statements has truth value F?

Answer»

`N_(2)`
`He`
`CO _(2)`
`H_(2)`

SOLUTION :Carbon dioxide, most STABLE gas and has lowest value of Henry.s Law constnat.
Discussion
39.

Which of the following statements are con-ect A) Carbamates are nerve toxins B) diethanol amine is an environment friendly herbicide C) Fly ash is a contaminent in air due to thermal power plants and steel industry D) Haemoglobin of the blood forms catboxy haemoglobin with CO The correct answer is

Answer»

A,B,C
B,C,D
A,B,D
A,B,C,D

Answer :D
Discussion
40.

Which one of the following is correct regarding sigma molecular orbital?

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The rotation ALONG theintern NUCLEAR axis is symmetric
It is FORMED y the parital overlap of atomic orbitals at right angle to inter nuclear axis
It is very weak bond
It has LESS overlaping region

Answer :A
Discussion
41.

Which of the following is a favourable factor for cation formation ?

Answer»

High electronegativity
High ELECTRON affinity
Low IONISATION potential
SMALLER ATOMIC size

Answer :C
Discussion
42.

Which of the following is not associated with electrophilic aromatic substitution?

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The formation of NITROBENZENE
The formation of benzyne
The formation of bromobenzene
The formation of benzene sulfonic ACID

Solution :The formation of nitrobenzene, bromobenzene and benzene sulfonic acid uses classical methods of eelctrophilic aromatic SUBSTITUTION chemistry. Benzyne is an intermediate in one of the NUCLEOPHILIC aromatic substitution reactions.
Discussion
43.

Write the Grometrical isomers of CHBr = CHBr.

Answer»

SOLUTION :
Discussion
44.

Which of the following pairs of d-orbitals witll have electron density along the axis-

Answer»

`d_(xy),d_(X^(2)-y^(2))`
`d_(Z^(2)),d_(XZ)`
`d_(xz),d_(yz)`
`d_(z^(2)),d_(x^(2)-y^(2))`.

SOLUTION :`d_(z^(2)),d_(x^(2)-y^(2))`.
Discussion
45.

Which of the following is thermally more stable

Answer»

`CaO_(2)`
`SrO_(2)`
`BaO_(2)`
All are equally stable

Answer :C
Discussion
46.

What is photoelectric effect? Give one example.

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Solution :It is the Emission of ELECTRON from surface of the meal by the action of LIGHT EG. `CH_(4)`
Discussion
47.

The values of DeltaH and DeltaS for a reaction are respectively "30 kJ mol"^(-1) and 100 KJ^(-1) mol^(-1). Then the temperature above which the reaction will become spontaneous is____

Answer»

300 K
30 K
100 K
`20^@C`

Solution :`DeltaG=DeltaH-T DeltaS`
At 300 K ,
`DeltaG=30000 "J mol"^(-1) -300 K xx 100 J K^(-1) mol^(-1)`
`DeltaG=0`
above 300 K ,`DeltaG` will be NEGATIVE and reaction becomes SPONTANEOUS.
Discussion
48.

Which one of the following is not a use of potash alum ?

Answer»

As a STYPTIC in arresting bleeding
As a pesticide
As a mordant in DYEING
As a COAGULANT for colloidal clay in water

Solution :Alum is not used as a pesticide.
Discussion
49.

What is the difference in pressure between the top and botton of a vessel 76 cm deep at 27^(@)C when filled with (i) water (ii) mercury ? Density of water at 27^(@)C is 0.990 g 0.990" g" cm^(-3) and that of mercury is 13.60" g cm"^(-3).

Answer»

Solution :PRESSURE `="height"XX"density"xx"G"`
Case (i). Pressure difference`=76" cm" xx0.99" g"cm^(3)xx981" cm"//s^(2)`
`=7.38xx10^(4)" dynes" cm^(-2)=0.73" atm" (1" atm"=1.013xx10^(6)" dynes "cm^(-2))`
Case (ii). Pressure difference `=76 cmxx13.6" g"//cm^(3)xx981" cm"//s^(2)=1.013xx10^(6)" dynes" cm^(-2)=1" atm"`.
Discussion
50.

The vapour pressure of pure benzene at a certain temperature is 640 mm of Hg. A non-volatile non-electrolyte solid weighing 2.175 g is added to 39 g of benzene. The vapour pressure of the solution is 600 mm of Hg. What is molecular weight of solid substance?

Answer»


ANSWER :[69.6]
Discussion