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.

Why are BeSO_(4) and MgSO_(4) readily soluble in water while CaSO_(4) , SrSO_(4) and BaSO_(4) are insoluble ?

Answer»

SOLUTION :Because of big size of `SO_(4)^(2-)` ion as compared to `Be^(2+)` and `Mg^(2+)` ions , the lattice enthalpies of `BeSO_(4)` and `MgSO_(4)` are almost the same . But because of small size of `Be^(2+)` and `Mg^(2+)` ions their hydration enthalpies are much higher than their corresponding lattice enthalpies . As a RESULT , `BeSO_(4)` and `MgSO_(4)` are highly soluble in water .
Discussion
2.

Which statements are correct for the peroxide ion-

Answer»

it has five completely filled anti-bonding molecular orbitals
it is DIAMAGNETIC
it has bond order one
It is isoelectronic with neon

Solution :MO electronic configuration of `O_(2)^(2-)` (peroxide ion):
`(sigma_(1s))^(2)(sigma_(1s)^(**))^(2)(sigma_(2s))^(2)(sigma_(2s)^(**))^(2)(sigma_(2p_(z)))^(2)`
`(pi_(2px))^(2)(pi_(2py))^(2)(pi_(2p_(x))^(**))^(2)(pi_(2p_(y))^(**))^(2)`
bond order`=(N_(b)-N_(a))/(2)=(10-8)/(2)=1`
THUS, there is no unpared electron present for which it becomes diamagnetic. its total no. of electrons=18 (same as that of Ne).
Discussion
3.

Which of the foollowing is /are basic huydroide ?

Answer»

HCl
`NH_(3)`
`H_(2)S`
`PH_(3)`

ANSWER :B,D
Discussion
4.

Which of the following is wrong for Bohr's model ?

Answer»

It establishes STABILITY of atom
It is inconsistent with HEISENBERG uncertai nity principle
It explains the CONCEPT of spectral lines for hydrogen like species
Electrons BEHAVE as particle and wave 

Answer :D
Discussion
5.

Which colour is shown by Calcium salts in flame test?

Answer»

LIGHT Green
Crimson red
Brick red
Violet

Answer :C
Discussion
6.

Which of the following alkanes may be synthesized from a single alkyl halide by a process involving coupling reaction?

Answer»

2-Methylbutane
2-Methylpropane
2, 3-Dimethylbutane
PROPANE

Solution :Only 2,3-dimethylbutane being symmetrical can be PREPARED by Wurtz REACTION.
Discussion
7.

Which one of the following alkali metals gives hydrated salts?

Answer»

Li
Na
K
Cs

Solution :DUE to the smallest size AMONG alkali metal IONS, `Li^(+)`ions possess maximum power to polarise `H_2O` MOLECULES, ATTACH them to themselves and get hydrated.
Discussion
8.

X. and .Y. are two different solutions of hydrochloric acidwith concentrations 5M and 2M respectively. If one litre of 3M hydrochloric acid is to be prepared by mixing only X and Y calculate their volumes.

Answer»

Solution :Volume of solution .X. is V mL
Volume of solution .Y. is (1000-V)mL
MOLARITY desired to be obtained =3M
Volume desired to be obtained =1000mL
`M=(Vxx5(1000-V)2)/(1000)=3`
SOLVING, V=333.3ml
The volumes of Solutions .X. and .Y. are to be MIXED are RESPECTIVELY 333.3mL and 666.7mL.
Discussion
9.

Which of the following halide is covalent

Answer»

`BeCI_(2)`
`MgCI_(2)`
`CaCI_(2)`
`BaCI_(2)`

SOLUTION :Due to more polarising power of Be it FORMS COVALENT HALIDES predominetly.
Discussion
10.

Which of the following statements is // are correct

Answer»

Catenation is the property of self linking of identical atoms among themselves giving rise to CHAINS and rings
Carbon and silicon have the remarkable property of catenation
Catenation power of carbon is more than that of silicon
Catenation power of carbon is less than of silicon

Solution :(ABC ) Due to their HIGH bond dissociation energies, the M-M bonds in carbon and silicon (C -C bond Si-Si) are extremely stable. In carbon ATOM the number of 4 valenceorbitalas ( one 2s `+` THREE 2p). Thus carbon is tetravalnet state is fully saturated, because it has neither VACANT orbital nor any lone pair of electrons on its atom due to which C-C bond is extremelystable
Discussion
11.

Wrong reaction of the following

Answer»

`Li_(2)CO_(3)OVERSET(Delta)rarr Li_(2)O+CO_(2)`
`4LiNO_(3)rarr 2Li_(2)O+4NO_(2)+O_(2)`
`2Li+O_(2)rarr Li_(2)O_(2)`
`CO_(3)^(2-) +H_(2)Orarr HCO_(3)^(-)+OH^(-)`

ANSWER :C
Discussion
12.

Which statements are correct for a process involving an ideal gas?

Answer»

`(Delta S)_("Isothermal, sys") = 2.303 N R "long" (V_(f))/(V_(i))`
`(Delta S)_("adiabatic, rev") = 0`
`(Delta S)_("TOTAL, irr") gt 0`
`(Delta S)_("Total, adiabatic, rev") = 0`

Solution :`Delta S = n C_(V) "ln" (T_(2))/(T_(1)) + nR "ln" (V_(2))/(V_(1))`
Isothermal `Delta S = nC_(V) "ln" (T_(2))/(T_(1)) + nR "ln" (V_(2))/(V_(1))`
Adiabatic, rev `RARR q_("rev") = 0 rArr Delta S = 0`
`rArr Delta S_("surr") = 0 rArr Delta S_("total") = 0`
for irreversible, `Delta S_("total") gt 0`
Discussion
13.

What is reaction quotient?

Answer»

Solution :Consider a homogenous reversible reaction `xA+yBhArrlC+mD`
For the above reaction under non-equilibrium conditions, reaction quotient Q is defined as the RATIO of the PRODUCT of active masses of reaction products RAISED to the respective stiochiometric coefficients in the balanced chemical EQUATION to that of the reactants.
Under non equilibrium conditions,
`Q=([C]^(l)*[D]^(m))/([A]^(x)*[B]^(V))`
Discussion
14.

Which of the following MO s have one nodal plane ? .

Answer»

`SIGMA 1S`
`sigma^(**) 1s`
`sigma 2p_(Z)`
`sigma^(**)2p_(z)`

Solution :All bonding `piMO` s and antibonding `sigma ^(**) MO s` and `overset(**)sigma 2p_(z)` have one nodal PLANE
Discussion
15.

When hydrogen peroxide is added to acidified potassium dichromate, a blue colour is produced due to formation of :

Answer»

`CrO_(3)`
`Cr_(2)O_(3)`
`CrO_(5)`
`CrO_(4)^(2-)`

Answer :C
Discussion
16.

Which oneis notcorrect ?

Answer»

`n=4,L =2 ,m=0`
`n=4,l=1,m=0`
`n=4,l=4,m=1`
`n=4,l=0,m=0`

ANSWER :C
Discussion
17.

Which of the following is a true structure of H_(2)O_(2) in solid phase?

Answer»




Solution :`H_(2)O_(2)` has an OPEN book STRUCTURE with H-O-O bond angle equal to `101.9^(@)` in SOLID PHASE.
Discussion
18.

Which metal is used in the window of X-ray tubes ?

Answer»

ZN
MG
Be
CA

ANSWER :C
Discussion
19.

What is equivalent mass of (NH2_4)_2Cr_2O_7in the change (NH_(4))_(2)Cr_(2)O_(7) rarr N_(2) + Cr_(2)O_3 + 4H_(2)O?

Answer»

`M/2`
`M/3`
`M/4`
`M/6`

Solution :`(NH_4)_(2)Cr_(2)O_7`
`2overset(-3)(NH_4^(+))rarroverset(0)(N_2)`
`2x +8 =+2 , 2x =-6 , E =M/6`
Discussion
20.

The volume of 10 moles of an ideal gas at 27^@C and latm pressure is 1 lit. What is the volume of 20 moles of same gas at same pressure and temperature?

Answer»

2 LIT 
4 lit 
1 lit 
8 lit 

ANSWER :A
Discussion
21.

Which of the following oxide behaves as acid as well as base

Answer»

`Cr_2O_3`
`CrO_3`
`CRO`
`CrO_5`

ANSWER :A
Discussion
22.

What is meant by condensed structure? Explain with an example.

Answer»

Solution :The bond LINE structure can be further abbreviated by OMITTING all these dashes REPRESENTING covalent bonds and by indicating the NUMBER of identical groups attached to an atom by a subscript. The resulting expression of the compound is called a condensed structural formula.
e.g., 1, 3-butadiene.
`UNDERSET(underset("Condensed Structure")(H_(2)=CH-CH=CH_(2)))(H-overset(H)overset(|)C=overset(H)overset(|)C-overset(H)overset(|)C=overset(H)overset(|)C-H)`
Discussion
23.

Which element of group six forms metal hydride ?

Answer»

Na
Cr
MN
Fe

Answer :B
Discussion
24.

The vapour density of PCl_(5) at 473 is found to be 70*2. Find the degree of dissociation of PCl_(5) at this temperature.

Answer»

Solution :Theoretical vapour density of `PCl_(5)` ,
`D=(" Mol.mass of " PCl_(5))/2 = (31 + 5 xx 35*5)/2 = (208*5)/2 = 104 * 25`
Observed vapour density , d= `70*2 `
`:. "Degree of dissociation " (ALPHA)=(104*25 - 70*2)/(70*2)=0*485`
Discussion
25.

Which of the following represents a chemical reaction ?

Answer»

OXIDATION -REDUCTION reaction
Acid-base NEUTRALIZATION reaction
Precipitation reaction
All of these

Answer :D
Discussion
26.

What is van't Hoff reaction isotherm ?

Answer»

Solution :The reaction `DELTA G^(@)= - RT ` In K is CALLED van't HOFF reaction isotherm.
Discussion
27.

Which curve in the following graph represents the curve of ideal gas ?

Answer»

B only
C and D only
E and F only
A and B only

Solution :For an ideal GAS graph between P and PV is straight line parallel to the pressure axis .
Discussion
28.

Which of the following is relatively stronger acid?

Answer»




SOLUTION :`-I.E` INCREASES ACIDITY
Discussion
29.

Which of the following shows geometrical isomerism.

Answer»

`BrCH=C=C=CHBr`<BR>
`CH=C=C=C" "Br_(2)`
`CH_(2)+C=C=CHBr`

ANSWER :A
Discussion
30.

xg of tartaric acid is dissolved in 30mL of 0.2M potash solution. The resultant mixture requires20ml of 0.1M HCl for titration. Report the numerical value of x.

Answer»

Solution :Tartaric ACID is a dibasic acid
HOOC-CHOH-CHOH-COOH
Gram molecular weight (GMW) = 150G , THEREFORE, GEW = 75g
m.eq . Of NaOH =m.eq . Of HCl
m.eq. of tartaric acid `=30xx0.2-20xx0.1=6-2=4`
Weight of tartaric acid DISSOLVED = Number m.eq`xx(75)/(1000)=(4xx75)/(1000)=0.3`
Numerical value of x=0.3
Discussion
31.

The RMS velocity of nitrogen gas molecules is 'V cm/sec at a certain temperature. When the temperature is doubled, the molecules dissociated into individual atoms. Now the RMS velocity of nitrogen atoms is x V cm/sec. What is the value of 'x'?

Answer»


Solution :`(C_(N_2))/(C_N) = V/(C_N) = SQRT((T_1)/(28) XX 14/(2T_1)) IMPLIES C_N = 2V`
Discussion
32.

What are amphoteric substances? Give examples.

Answer»

SOLUTION :A SUBSTANCE or molecule which ACTS both as ACID as well as base, is called amphoteric.
Examples:
Discussion
33.

Why are potassium and cesium, rather than lithium used in photoelectric cells ?

Answer»

Solution : All the three, lithium, potassium, and cesium, are ALKALI metals. Still, K and Cs are USED in the photoelectric cell and not LI. This is because as compared to Cs and K, Li is smaller in size and therefore, requires high energy to lose an electron. While on the other HAND, K and Cs have low ionization energy.
Hence, they can easily lose electrons. This property of K and Cs is utilized in photoelectric cells.
Discussion
34.

When ethene gas is passed through an aqueous solution containing bromine and sodium chloride, three products are formed. Predict the products.

Answer»

SOLUTION :
Discussion
35.

Which one is ionic hydride in nature?

Answer»

CrH
`NH_(3)`
`H_(2)O`
`NaH`

Answer :D
Discussion
36.

Velocity of the electron in the 1^(st) Bohr orbit

Answer»


ANSWER :`2.18 XX 10^(8) cm^(-1)`
Discussion
37.

What will be order of reactivity of following compounds towards addition of HBr ?

Answer»


ANSWER :IV > III > II > I
Discussion
38.

Which of the following does not form volatile product with conc. H_(2)SO_(4)?

Answer»

`CO_(3)^(2-)`
`SO_(4)^(2-)`
`CI^(-)`
`NO_(3)^(-)`

ANSWER :B
Discussion
39.

Which one of the following reactions does not form gaseous product?

Answer»

`PbO_(2)+H_(2)O_(2)to`
`PbS+H_(2)O_(2)to`
`Cl_(2)+H_(2)O_(2)to`
`Na_(2)CO_(3)+H_(2)O_(2)to`

Answer :B
Discussion
40.

The stable oxidation state of Thallium, a IIIA group element is

Answer»

`+1`
`+3`
`-3`
`+5`

ANSWER :A
Discussion
41.

Which of the following acidic radicals produce colourless gas with dilute HCI which does not react with oxidising agent?

Answer»

`CO_(3)^(2-)`
`SO_(3)^(2-)`
`S^(2-)`
All of these

Answer :A
Discussion
42.

Which one of the following is a gem-dihalide?

Answer»

`CH_3CHCl_2`
`{:(CH_2-CH_2),(|""|),(CL""Cl):}`
`CH_3 - CH_2Cl`
`C_6H_4Cl_2`

SOLUTION :`CH_3CHCl_2`
Discussion
43.

Which of the following chemical reactions depicts theoxidising behaviour of H_(2)SO_(4)?

Answer»

`2HI + H_(2) SO_(4) rarr I_(2) + SO_(2) + 2H_(2)O`
`Ca(OH)_(2) + H_(2) SO_(4) rarr CaSO_(4) + 2H_(2)O`
`NaCl + H_(2)SO_(4) rarr NaHSO_(4) + HCl`
`2PCl_(5) + H_(2)SO_(4) rarr 2POCl_(3) + 2HCL + SO_(2) Cl_(2)`

Answer :A
Discussion
44.

Which mixture of gases is produced on heating Tin oxalate (SnC_2O_4) ?

Answer»

`CO+CO_2`
`CO_2+O_2`
`CO_2+O_3`
`CO+O_2`

ANSWER :A
Discussion
45.

The type of hybridisation of boron in diborane is (a) sp, (b) sp^(2) ,(c) sp^(3) ,(d) dsp^(2)

Answer»

SP
`sp^2`
`sp^3`
`dsp^2`

SOLUTION :`sp^3`
Discussion
46.

Which scientist declared, "Properties of elements are periodic with their atomic mass"?

Answer»

NEWLAND
Mendeleev
Lother MEYER
Mosseley

ANSWER :B
Discussion
47.

Which of the following is the smallest in size?

Answer»

`NA^(-)`
`O^(-2)`
`Na^(+)`
`F^(-)`

ANSWER :C
Discussion
48.

The rms speed of helium in ms^(-1) (atomic mass = 4.0g mol^(-1)) at 400K is

Answer»

1580
15.8
28
158

Answer :A
Discussion
49.

What is similarity and difference between Lewis structure of H_(2)SO_(4) and SO_(4)^(2-) ?

Answer»

Solution :There are same NUMBERS of bonding and non bonding electrons in both atoms.
`H_(2) SO_(4)` contain two H and neutral. In `SO_(4)^(2-), ` H is not PRESENT and CHANGE is - 2 because `H^(+) ` is remove but electron of H is remains in `SO_(4)`.
Discussion
50.

Trans-2-Butene overset(HOBr)to P (product ) , 'P' is :

Answer»




ANSWER :A::D
Discussion