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.

At low pressure Vander Waal's equation for 3 moles of a real gas will have its simplified from

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`(PV)/(RT-(3a//V)) = 3`
`(PV)/(RT + Rb) = 3`
`(PV)/(RT - 3Pb) = 1`
`(PV)/(RT - (9//V)) = 3`

Solution :LOW `P IMPLIES` negligible b
`(P + (an^2)/(V^2)) (V) = n^(RT) ,` for 3 moles
`(P + (a XX 9)/(V^2)) (V) = 3RT`
`PV + (9a)/V = 3RT , PV = 3 (RT - (3a)/(V))`
2.

At low pressure, the fraction of the surface covered follows

Answer»

zero-ORDER REACTION
second-order reaction
first-order reaction
FRACTIONAL order

ANSWER :C
3.

At low pressure of 0.25 atm, 2 mole of a real gas has Boyl's temperature 100K. The approximate volume of gas at this temperature and pressure is:

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66 litre
33 litre
44.8litre
none of these

Answer :a
4.

At K, K_(p) = 2*0 xx 10 ^(10)//"bar" for the given reaction at equilibrium 2 SO_(2) (g) + O_(2) (g) hArr 2 SO_(3) (g) What is K_(c) at this temperature ?

Answer»

Solution :For the given reaction , ` Delta n_(g)= 2 -3 = -1 `
` K_(p) = K_(c) (RT)^(Delta n) or K_(c) = K_(p) (RT)^(-Delta n)= K_(p) (RT) = ( 2*0 xx 10^(10)"bar"^(-1))(0*0831 L "bar" K^(-1) "MOL" ^(-1) ) ( 450 K)`
` = 7.48 xx 10^(10 )L"mol"^(-1) = 7*48 xx 10^(11) L "mol"^(-1)`
5.

At its melting point ice is lighter than water because

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`H_(2)O` molecules are more closely packed in solid state
ICE crystals have hollow HEXAGONAL arrange-ment of `H_(2)O` molecules shrinks in size
On MELTING of ice the `H_(2)O` molecules shrinks in size
Ice forms MOSTLY heavy water on first melting

ANSWER :B
6.

At isoelectric point

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colloidal PARTICLES migrate towards oppositely charged ELECTRODES
coagulates
becomes electrically neutral
pH of the solution becomes 7

Solution :At isoelectric point, colloidal particles do not migrate towards oppositely charged electrodes as at isoelectric pH, colloidal particles do not carry any CHARGE. The pH at isoelectric point not 7.
7.

At infinite dilution , the percentage ionisation of both strong and weak electrolytes is

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`1%`
`20%`
` 50%`
` 100%`

Solution :` ALPHA = sqrt((K_a)/(C)) "as " c to 0, alpha to 1`
8.

At identical temperature and pressure, the rate of diffusion of hydrogen gas is 3sqrt(3) times that of a hydrocarbon having molecular formula C_(n)H_(2n-2). What is the value of n ?

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Solution :`(gammaH_(2))/(gammaC_(n)H_(2n-2))=SQRT((m_(C_(n)H_(2n-2)))/(m_(H_(2))))`
`3sqrt(3)=sqrt((m_(C_(n)H_(2n-2)))/(2))`
Squaring on both SIDES and REARRANGING
`27xx2-m_(C_(n)H_(2n-2))`
`54=n_(12)+(2n-2)(1)`
`54=12n+2n-2`
`n=(54+2)//14`
`=56/14=4`
`:.n=4`
9.

At identical conditions of temperature and pressure for complete combustion of 10 m^3 of sulphur dioxide volume of oxygen required is_______ .

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`1m^(3)`
`5m^(3)`
`10M^(3)`
`20m^(3)`

SOLUTION :`{:(2SO_(2(G)),+O_(2(g)) to, 2SO_(3(g))),(2 "volume ",1 "volume",2 "volume"),(10 m^3,5 m^3,10m^3):}`
10.

At idential tempreture and pressure , yhe rate of diffusion of hydrogen gas is 3sqrt3 times that of a hydrocarbon having moleculer formula C_(n)H_(2n-2) What is the value of n?

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8
4
3
1

Solution :`gamma_(H_(2))/(gammac_(n_(H_(2n+2))))=sqrt(mc_(n)H_(2n+2)/m_(H_(2)))Rightarrow3sqrt3=sqrt(m_(c_(n_(H_(2n+n))))/2)`
SQUARING on both sides and rearring
`27xx2=m_(c_(n_(H_(2n-n))))`
`54=n(12)+(2n-2)(1)`
`54=12n+2n-2=14n-2`
`n=(54+2)/14=56/14=4` .
11.

At high temperature , boron burns in air to give a mixture of B_2 O_3 and BN.

Answer»


ANSWER :1
12.

At half-neutralisation of a weak acid with a strong base, what is the relationship between pH and dissociation constant (K_(a)) of the weak acid ?

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SOLUTION :at HALF- NEUTRALISATION, `PH = pK_(a)`.
13.

At given temperature , these reaction tell about control of reaction which is :

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ANSWER :A
14.

Vapour pressure is an important property of liquids.pressure cooker is used for cooking food at higher altitudes. Give reason.

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Solution :SINCE atmospheric PRESSURE is low at high attitudes, the NORMAL boiling point of water will be low. So food cannot be cooked properly. So pressure COOKER is used for cooking
15.

At equilibrium, the value of equilibrium constant K is

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`1`
`2`
`3`
`0`

Solution :At EQUILIBRIUM `DeltaG=0`
`DeltaG=-nRT LN K`
`0=- nRT ln K`
or `K=1`
16.

At equilibrium, the concentrations of N_(2) = 3*0 xx 10^(-3) M, O_(2)= 4*2 xx 10^(-3) M and No = 2*8 xx 10^(-3) M in a sealed vessel at 800 K. What will be K_(c) for the raction N_(2) (g) + O_(2) (g) hArr 2 NO (g) ?

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ANSWER :`0*622`
17.

At equilibrium , the mass of each of the reactants and products remains constant. Does it mean that the reaction has stopped ? Explain.

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Solution :No, the reaction does not STOP. In CONTINUES totake place in the FORWARD as well as BACKWARD directions but at equal speeds.
18.

At equilibrium, the concentration of : N_2=3.0xx10^(-3) M, O_2=4.2xx10^(-3) M and NO=2.8xx10^(-3) M in a sealed vessel at 800 K. What will be K_c for the reaction N_(2(g)) + O_(2(g)) hArr 2NO_((g))

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Solution :`{:("REACTION:" ,N_(2(g)) + , O_(2(g))hArr , 2NO_((g))),("Concentration at equilibrium:" , 3.0xx10^(-3)M, 4.2xx10^(-3)M,2.8xx10^(3)M):}`
Equilibrium CONSTANT of reaction is `K_c`,
`K_c=[NO]^2/([N_2][O_2])=(2.8xx10^(-3)M)^2/((3.0xx10^(-3)M)(4.2xx10^(-3)M))`
= 0.6222
19.

At equilibrium state

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`DeltaG^@=0`
`DeltaG = "negative"`
`DeltaG = "zero"`
`DeltaG = "POSITIVE"`

SOLUTION :at equilibrium, `DELTA G=0`
20.

At equilibrium of the reaction,N_(2)O_(4) (g) hArr2 NO_(2) (g), the obsserved molecular weight ofN_(2)O_(4) is 80 g " mol "^(-1)at 350 K. The percentage of dissociation of N_(2)O_(4) (g) at 350 K is

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0.1
0.15
0.2
0.18

Solution :For the GIVEN dissociation REACTION ,
`alpha =(D-d)/d = (M_(t)-M_(o))/(M_(o))=(92 xx80)/80 xx 100 = 15%`
21.

At equilibrium, Kp = 1 then the value of AG^(@) will be equal to.....

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Solution :`DELTA G^(@)= -RT L N K=0`
22.

At ......... distance the four oxygen atoms surrounded to each oxygen atom in ice.

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`2.76xx10^(-10)` m
2.76 Å
276 PM
All of

SOLUTION :1M=`10^12` pm = `10^10` Å
23.

At definite temperature total pressure is P bar derive equilibrium constant. CaCO_(3(s)) hArr CaO_((s)) + CO_(2(g))

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SOLUTION :`CaCO_(3(s)) hArr CaO_((s)) + CO_(2(G))`
`{:("Initial",-,-,),("At equilibrium",-,-,p_(CO_2)):}`
`K_c=([CaO_((s))][CO_(2(g))])/([CaCO_(3(s))])`
`CaCO_(3(s))` and `CaO_((s))`are solid so take its concentration CONSTANT.
`therefore K_c=[CO_2]` and `K_p =p_(CO_2)`=P BAR
24.

At definite temperature K_c is given by following equation, K_c=([I_2][H_5IO_6]^5)/([IO_3^(-)]^7[H_2O]^9[H^+]^7) Write the equilibrium equation.

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Solution :`7IO_(3(aq))^(-) + 9H_2O_((L)) + 7H_((aq))^(+) HARR I_(2(aq)) + 5H_5IO_(6(aq))`)
25.

At definite temperature in open vessel decomposition of Ammonium carbonate take place and total pressure is P bar derive K_p. (NH_4)_2CO_(3(s)) hArr 2NH_(3(g)) + CO_(2(g)) +H_2O_((g))

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Solution :`{:("Reaction:",(NH_4)_2CO_(3(s)) hArr , 2NH_(3(g))+ , CO_(2(g)) + , H_2O_((g))),("Pressure at equilibrium:",,2x,X,x),("If total pressure P, So partial pressure",,(2P)/4,P/4,P/4):}`
Total Pressure P=2x +x+ x = 4x `THEREFORE x=P/4`
`therefore 2x=p_(NH_3)=(2P)/4`
`x=p_(CO_2)=p_(H_2O)=P/4`
`K_p=(p_(NH_3))^2(p_(CO)_2) (p_(H_2O))`
`=((2P)/4)^2(P/4)(P/4)`
`=P^4/64 "bar"^2`
26.

At definite temperature if the volume of system decrease then what will be change in concentration of CO ? 2CO_((g)) + O_(2(g)) hArr 2CO_((g))

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Solution :At the VOLUME decrease so the total pressure INCREASES so the reaction MOVES in such direction where moles are less and reaction moves in forward direction.
`ubrace(2CO_((g))+O_(2(g)))_("3 mole") hArr UNDERSET"2 mole"(2CO_(2(g))) `
27.

At definate temperature. The reaction,SO_(2(g)) + 1/2O_(2(g)) hArr SO_(3(g)) DeltaH=-94.7 kJ is in closed vessel. The equilibrium will be go in which direction by following changes ?(i) Increase temperature (ii) Addition of catalyst (iii) addition of SO_2 gas (iv) To decrease total pressure (v) If volume of vessel will increase (vi) Addition He gas at constant volume (vii) addition He gas at constant pressure.

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Solution :(i) If the temperature will increase than reaction is endothermic therefore equilibrium shift in the reverse direction.
(ii) Adding of catalyst, the reaction is not shift in any direction. The catalyst affect the same on speed of forward and backward reaction.
(iii) `SO_2` gas is reactant. If the reactant will be added, it decrease and the equilibrium shift in forward direction.
(iv) If TOTAL pressure decrease than such reaction take place in which pressure increase and moles of gas increase. In this reaction 1.5 mole gaseous reactant and 1 mole gases product. So on decreasing pressure mole charge from 1 to 1.5.
(v) If the volume of vessel increase therefore pressure will be decrease and the reaction is reverse and decrease the product `SO_3` while increase the reactant `SO_2`
(vi) If the reaction take place at CONSTANT volume, addition of inert gas like He will not change the molar concentrations of the REACTANTS and products hence, the state of equilibrium will remain unaffected.
(VII) Reverse reaction is occurs. At constant temperature if inert gas is added the PARTIAL pressure of gases change. As gaseous reactants are more reaction proceed in reverse direction.
28.

At definite temperature 3 atm pressure 75% PCl_5 decompose in PCl_3 and Cl_2. Find K_p.

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SOLUTION :3.851 ATM
29.

At definite temp the K_c of the following reaction is 0.18. PCl_(3(g))+Cl_(2(g)) hArr PCl_(5(g)) At a definite temp. in reactionmixture [PCl_3]= 0.042 M , [Cl_2]= 0.024 M and [PCl_5]= 0.005 M . Is this reaction in equilibrium ? In which direction reaction moves ?

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Solution :`Q_c=4.96 gt K_c` THEREFORE not equilibrium. Equilibrium constant decreasing to 0.18 and the REACTION will be in reverse direction.
30.

At definite temp if the volume of system decrease than what will be change in concentration of CO ? 2CO_((g)) + O_(2(g)) undersetlarrto 2CO_(2(g))

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Solution :`{:(," "2CO_((g))+O_(2(g)) undersetlarrto,2CO_(2(g))),("total","3 MOLES reactant","2 moles PRODUCT"):}`
As the volume of system decreases , pressure INCREASES and by decreasing the moles of gaseous substances forward REACTION will occurs and concentration of CO will decrease.
31.

At critical temperature:

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liquid passes into GASEOUS state imperceptibly and continously
gas passes into liquid state imperceptibly and continously
surface SEPARATING two PHASES DISAPPEARS
all of the above

Answer :d
32.

At critical point, the surface tension is "___________________".

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infinite
zero
same as that at ROOM temperature
twice as that at room temperature

Answer :B
33.

At constant volume Z_(11) is directly proportional to:

Answer»

<P>`SQRT(P)`
`P`
`T^(2)`
T

Answer :a
34.

At constant volume, for a fixed number of moles of a gas, the pressure of the gas increases with a rise in temperature, due to

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increases in average molecular SPEED 
decreased NUMBER of collisions amongst molecules 
increase in molecular ATTRACTIONS 
DECREASE in mean free path

Solution :`P uarr` due to more collisions with walls of container which is due to increased average molecular speed.
35.

At constant temperature, the equilibrium constant K_(p) N_(2)O_(4) hArr 2NO_(2) is given by k_(p) = (4x^(2)P)/(1 - x)were ,P = Pressure and X= Extent of reaction How does the value of K_(p)change on following changes (a) 'P' increases (b) X changes (c ) 'P' decreases

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SOLUTION :`K_(p)`is equilibrium constant which does not change on CHANGING the P, X. `K_(p)`DEPENDS on temperature.
36.

At constant temperature the vapour pressure of water, acetone and ether are respectively 23.3, 24.6 and 56 atm. state the order of boiling point.

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Solution :Boiling point `ALPHA` 1/vapour pressure
`therefore`ETHER, ACETONE, water are in increasing ORDER ( `because` vapour is more so, b.p. is less)
37.

At constant temperature, the equilibrium constant (K_(p)) for the decomposition reaction N_(2)O_(4) hArr 2NO_(2) is expressed by K_(p) = 4x^(2) P//(1 - x^(2)) where Pis pressure, x is extent of decomposition. Which of the followingstatement is true ?

Answer»

`K_(P)` increases with INCREASE of P
`K_(P)` increases with increase of X
`K_(P)` increases with decrease of x
`K_(P)` REMAINS CONSTANT with change in P or x

Solution :`K_(P)` does not change with P, x CHANGES according to Le-chatelier.s principle
38.

At constant temperature, in a given mass of an ideal gas

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the ratio of PRESSURE and VOLUME ALWAYS remains constant
volume always remains constant
pressure always remains constant
the product of pressure and volume always remains constant.

Solution :the product of pressure and volume always remains constant.
39.

At constant temperature & volume , 50% of ozone is decomposed out of 2 atm of ozone taken initially and the equilibrium 2O_(3 (g)) hArr 3O_(2 (g)) is established , K_(p) for the decomposition of ozone is

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`((3)/(2))^(3)`
`((3)/(2))^(2)`
`((2)/(3))^(3)`
`((2)/(3))^(2)`

ANSWER :A
40.

At constant temperature a gas occupies a volume of 200 mL at a pressure of 0.720 bar. It is subjected to an external pressure of 0.900 bar. What is the resulting volume ?

Answer»

<P>

SOLUTION :GIVEN
`V_(1)=200mL`
`P_(1)=0.720mL`
`P_(2)=0.900`bar
`V_(2)=?`
`V_(1)P_(1)=P_(2)V_(2)`
`thereforeV_(2)=(P_(1)V_(1))/(P_(2))=(0.720xx200)/(0.900)=160mL`
41.

At constant temperature 80% AB dissociates into A_(2) and B_(2) then the equilibrium constant for 2AB_((g)) harr A_(2(g)) +B_(2(g))

Answer»

1
0.25
16
4

Solution :
`K=(0.4 XX 0.4)/((0.2)^(2))=4`
42.

At constant pressure, the volume of a given mass of a gas ......... by 1/273 of its volume at ........... for each one degree rise in temperature.

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SOLUTION :INCREASES, `0^@C`
43.

At constant pressure, the heat of combustion of carbon monoxide at 17^0 C is –284.5 kJ. Calculate its heat of combustion at constant volume

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SOLUTION :` 283.3 KJ`
44.

At constant pressure for a given amount of an ideal gas, will the graph obtained by plotting V vs t^(@)C and V vs TK be different ?

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Solution :ACCORDING to Charles' law V=KT. . .[1]
[at CONSTANT pressure for a given mass of a gas]
But T=273+t, hence, V=K(273+t) . . [2]
Both the equation [1] & [2] express equations for straight lines. Equation no [1] represents a straight line passing through the origin. equation no. [2] does not represent a straight line passing through the origin. the plot of V vs t results in a straight line that cuts the V-axis at `0^(@)C`. if this straight line is extrapolated BACKWARD, it meets the t-axis at `-273^(@)C`. LTBRGT
From the, above two graphs it is evident that there are no actual defferences between the two graphs, because `-273^(@)C` and 0K express the same temperature.
45.

At CMC the surfactant molecule

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decomposes
becomes COMPLETELY soluble
associates
dissociates.

Answer :C
46.

At chemical equilibrium ,

Answer»

RATE of FORWARD reaction = rate of BACKWARD reaction
rate of forward reaction `GT` rate of backward reaction
rate of forward reaction `lt` rate of backward reaction
rate of forward reaction `prop` rate of backward reaction

Solution :rate of forward reaction = rate of backward reaction
47.

At certain temperature the volume - pressure curves for four gases A , B , C and D are as shown below . The gas that deviates least from ideal nature is

Answer»

B
D
C
A

Solution :Ideal gas can be HIGHLY compressed at HIGH pressure , because there are no intermolecular FORCES of ATTRACTION orrepulsion between is molecules .
48.

At certain temperature the proton concentration of pure water is 2.5 xx10^(-7) M. What is the hydroxyl ion concentration ? What is the magnitude of K_w ?

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Solution :For pure WATER, `[H^+] = [OH^(-)]`
Concentration of `[OH^(-) ] = 2.5 XX 10^(-7) M`
Ionic product of water `= K_w= [H^+ ][OH^(-)] = (2.5xx10^(-7) M)^2 = 6.25 xx 10^(-14)mol^2 L^(-2)`
49.

At certain temperature the K_(w) of D_(2),O is 10^(=-16) M. Then the pD of pure D_(2),O at that temperature is

Answer»

<P>7
16
8
6

Solution :` K_w " of "D_2O =10 ^(-16), [D^(+) ] [OD^(-)] = 10 ^(-16) `
` [D^(+)]= 10^(-8)M RARR P^(D) = 8`
50.

At certain temperature, the hydroxyl ion concentration of pure water is 8.4 xx 10^(-8) M. Calculate the ionic product at this temperature.

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SOLUTION :`7.0 XX 10^(-15)`