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24601.

The rate of reactino of which of the following is not affected by pressure

Answer»

`PCl_(3)+Cl_(2)hArrPCl_(5)`
`N_(2)+3H_(2)hArr2NH_(3)`
`N_(2)+O_(2)hArr2NO`
`2SO_(2)+O_(2)hArr2SO_(2)`

Solution :`HN_(2)+O_(2)hArr2NO,Deltan=0`
24602.

The rate of radioactive decomposition corresponding to 3.7 xx 10^(10) disintegration per second is called a curie. What weight of ""^(225)Ra, whose t_((1)/(2))=1620 yr, will be required to yield 1 millicurie of radiation?

Answer»

SOLUTION :`1 xx 10^(-3)G`
24603.

The rate of physisorption

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DECREASES with increase of pressure
is independent at high pressure
is maximum at ONE atmospheric pressure
INCREASES with increases of pressure

Answer :B
24604.

The rates of most reactions double when their temperature is raised from 298 K to 308 K. Calculate their activation energy.

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SOLUTION :`logK_2/K_1=E_a/(2.303R)[1/T_1-1/T_2]`
`E_a=(2.303xx8.314xx298xx308xx0.3010)/1000`
`E_a`=52.89 KJ/mol
24605.

The rate of most reactions becomes double when their temperature is raised from 298 K to 308 K. Calculate their activation energy.

Answer»

Solution :`T_(1) = 298 K, T_(2) = 308 K`.
`R = 8.314 J mol^(-1) K^(-1)`
Activation energy
`K_(2) = 2K_(1)`
`log.(K_(2))/(K_(1)) = (E_(a))/(2.303 R)[(T_(2)-T_(1))/(T_(1) XX T_(2))]`
`log 2 = (E_(a))/(2.303 xx 8.314)[(308 - 298)/(308 xx 298)]`
`0.3010 = (E_(a))/(19.147)[(10)/(91784)]`
`0.3010 = (E_(a))/(19.147) xx 1.08 xx 10^(-4)`
`E_(a) = (0.3010 xx 19.147)/(1.089 xx 10^(-4))`
`= (5.763)/(1.089 xx 10^(-4))`
`= 52922.37 J mol^(-1)`
24606.

The rate of forward reaction is two times that of the reverse reaction at a given temperature and identical concentration. K_("equilibrium") is

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`0.5`
`1.5`
`2.5`
`2.0`

Solution :`K_(eqm)=(k_(f))/(k_(B))=(2)/(1)=2`
24607.

The rate of Hoffmann's bromamide degradation with following amide will follow the order:

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`III gtIgtIVgtII`
`IIgtIVgtI LT III`
`IgtIIltIIIltIV`
`IgtIIIgtIVgtII`

Solution :GROUP having -I EFFECT slow down the REACTION.
24608.

The rate of forward reaction is two times that of reverse reaction at a given temperaturee and identical concentration. K_("equilibriuim") is

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`2.5`
`2.0`
`0.5`
`1.5`

Solution :The RATE of forward reaction is two TIMES that of reverse reaction at a given temperature and identical concentration `K_("equlibrium")` is 2 because the reaction is REVERSIBLE. So `K=(K_(1))/(K_(2))=2/1=2.`
24609.

The ratio of the forward reaction is two times that of the revers reaction at a given temperature and identical concentration.K_("equilibrium") is

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2.5
`2.0`
0.5
1.5

Solution :The rate of a forward reaction is two times that of reverse reaction at a given temperature.
`(d[A])/(DT)=2(d[B])/(dt)`
`K_("EQUILIBRIUM")=(K_(1))/(K_(2))=(d[A]//dt)/(d[B]//dt)=2(d[B]//dt)/(d[B]//dt)=2`.
`thereforeK_("equilibrium")=2`.
24610.

The rate of formation of SO_(3) in the reaction 2SO_(2)+O_(2)to2SO_(3) is 100 g "min"^(-1) Hence rate of disappearance of O_(2) is

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`50g"min"^(-1)`
`100g "min"^(-1)`
`20G"min"^(-1)`
`40G"min"^(-1)`

Answer :C
24611.

The rate of formation of NO(g) in the reaction 2NOBr(h) to 2NO(g)+Br_(2)(g) was reported as 1.6xx10^(-4)mol^(-1)sec^(-1). What is the rate of reaction and rate of consumption of NOBr?

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SOLUTION :`8XX10^(-5)`, `1.6xx10^(-4)MSEC^(-1)`
24612.

The rate of formation of ammonia by the reaction: N_2 +3H_2 to 2NH_3 expressed as (d[NH_3])/(dt)= 2.5xx 10^(-4)molL^(-1)s^(-1) The rate of consumption expressed in terms of H_2 as (-d[H_2])/(dt) will be

Answer»

double
THREE times
Same
one and a HALF TIME of that EXPRESSED in terms of `NH_3`

SOLUTION :`1/2(dNH_3])/(dt)=-1/3(d[H_2])/(dt) or -(d[H_2])/(dt)=3/2xx(d[NH_3])/(dt)`
24613.

The rate of formation of a dimer in a second order reaction 7.5xx10^(-3) "mol L"^(-1)s^(-1)at 0.05"mol L "^(--1)monomer concentration. Calculate the rate constant.

Answer»

Solution :LET us consider the DIMERISATION of a MONOMER M .
`2M rarr(M)_2`
Rate `=k[M]^n`
Given that n = 2 [ M] `=0.05 "mol L"^(-1)`
Rate `=7.5xx10^(-3) "mol L"^(-1)s^(-1)`
`k=("Rate")/([M]^n)impliesk=(7.5xx10^(-3))/((0.05)^2)=3 "mol"^(-1)Ls^(-1)`
24614.

The rate of formation of a dimer in a second order reaction is 7.5xx10^(-3)"mol L"^(-1)s^(-1) at 0.05"mol L"^(-1) monomer concentration. Calculate the rate constant.

Answer»

SOLUTION :Let US consider the dimerisation of a monomer M
`2Mrarr(M)_(2)`
`"Rate "=k[M]^(n)`
`"Given that n = 2 and [M]"="0.05 MOL L"^(-1)`
`"Rate "=7.5xx10^(-3)" mol L"^(-1)s^(-1)`
`k=("Rate")/([M]^(n))RARR k=(7.5xx10^(-3))/((0.05)^(2))="3 mol"^(-1)L s"^(-1)`
24615.

The rate of formation of a dimer in a second order dimerisation reaction is 9*5xx10^(-5)molL^(-1)s^(-1)" at "0*01molL^(-1) monomer concentration. Calculate the rate constant.

Answer»

Solution :If the monomer is represented by A, then the reaction is : `2Ato(A)_(2)`
As the reaction is of SECOND ORDER, the rate of reaction will be given by : Rate `=k[A]^(2)`
Rate of reaction `=-(1)/(2)(d[A])/(dt)=+(d[A_(2)])/(dt)=9*5xx10^(-5)molL^(-1)s^(-1)`
`:.9*5xx10^(-5)"MOL "L^(-1)s^(-1)=k(0*01"mol "L^(-1))^(2)=kxx10^(-4)("mol "L^(-1))^(2)" or "k=0*95L" mol"^(-1)s^(-1)`
24616.

The rate of first order reaction increases:

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If the temperature is increased
If the CONCENTRATION of the REACTANTS is decreased
If the concentration of the reactants is increased
With time

Solution :rate `prop` temperature , rate `prop` CONC. Of reactants
24617.

The rate of fchemical reaction depends on the nature of chemical reactions, because

Answer»

the threshold energy LEVEL differs from one reaction to another
some of the reactant are solid at room temperature
some of the REACTANTS are coloured
all

Solution :Difference in thershold energybarrier given difference values of energy of activation.
Also `K = Ae^(-E//RT)` and rate `= k ["reactant"]^n`
24618.

The rate of first order reaction A rarr Products, is7.5xx10^-4 mole litre^-1sec^-1.If the concentration of A is 0.5 mole litre-1the rate constant is:

Answer»

`3.75xx10^-4sec^-1`
`2.5xx10^-5sec^-1`
`1.5xx10^-3sec^-1`
`8.0xx10^-4sec^-1`

ANSWER :C
24619.

The rate of elementary reaction, A to B, increases by 400 times when the concentration of A is increased twenty folds. The order of the reaction with respect to A is

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1
2
10
100

Solution :`r = K [A]^m`…(i)
ALSO, `400r = k [20A]^m` …(ii)
From (ii)`-:`(i)
`400 = (20)^m`
`(20)^2 = (20)^m` ltbRgt `:.m = 2`
24620.

The rate of elementary chemical reaction is directly proportional to:

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ACTIVE masses of REACTANTS
EQUILIBRIUM constant
Active masses of PRODUCTS
PRESSURE of reaction

Answer :A
24621.

The rate of effusion of a particular gas whas measured to be 40ml/min. Under same condition the rate of effusion of pure methane was 20ml/min. Then find molar mass of gas.

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4amu
2amu
4GM
2gm

Solution :`(r_(CH_(4)))/(r_(GAS))=sqrt((M_(gas))/(16))=(20)/(40)=(1)/(2)`
`M_(gas)=4gm`
24622.

The rate of disapperance of SO_(2) in the reaction 2SO_(2) + O_(2) to 2SO_(3) is 1.28 xx 10^(-3)g/secthen the rate of formation of SO_(3) is

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`0.64xx 10^(-3)` G /sec
`0.80xx 10^(-3)` g /sec
`1.28xx 10^(-3)` g /sec
`1.60xx 10^(-3)` g /sec

SOLUTION :The RATE of formation of `SO_(3)` is `1.28 XX 10^(-3)` g/sec.
24623.

The rate of disappearance of CO in the reaction, 2 CO +O_2 to 2CO_2 is 1.28 xx 10^(-3)g//sec. Then the rate of formation of CO_2 is

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`0.64 xx 10^(-3) g// sec`
`0.80 xx 10^(-3) g //sec`
`1.28 xx 10^(-1) g//sec`
`1.28 xx 10^(-3) g//sec`

Solution :`Rate = -1/2(DT[CO])/(dt)=-(d[O_2])/(dt)=+1/2(d[CO_2])/(dt)`
Rate of FORMATION of CO
= rate of disappearance of `CO_2`
`=1.28xx10^(-3)g//sec`
24624.

The rate of diffusion of two gases x and y is in the ratio of 1 : 5 and that of y and z in the ratio of 1 : 6 the ratio of the rate of diffusion of z with respect to x is :

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`5:6`
`1:30`
`6:5`
`30:1`

Solution :`(r_(x))/(r_(y))=(1)/(5)""....(i)""(r_(g))/(r_(z))=(1)/(6)""....(ii)`
`(i)xx(ii) : (r_(x))/(r_(z))=(1)/(30)IMPLIES (r_(z))/(r_(x))=(30)/(1)`
24625.

The rate of diffusion of SO_2 and O_2 at the same P and T are in the ratio (S = 32, O = 16):

Answer»

1:32
1:4
1:2
`1:SQRT2`

ANSWER :D
24626.

The rate of diffusion of methane at a given temperature is twice that of a gas X. The molecular weight of X is

Answer»

64
32
4
8

Answer :A
24627.

The rate of diffusion of methane at a given temperature is twice that of a gas X. The molecular weight of X is :

Answer»

64
32
4
8

Answer :A
24628.

The rate of diffusion of a sample of ozonised oxygen is 0.98 times more than that of pure oxygen. Find the percentage (by volume) of ozone in the ozonised sample.

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ANSWER :`8.25%`
24629.

The rate of diffusion of gas is ……… proportional to both ....... of molecular mass.

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SOLUTION :INTERCEPT =RT
24630.

The rate of decomposition of N_(2)O_(5) in C Cl_(4) solution has been studied at 318 K and the following results have been obtained : {:(t//min,,,0,,,135,,,342,,,683,,,1693),(c//M,,,2.08,,,1.91,,,1.67,,,1.35,,,0.57):} Find the order of the reaction and calculate its rate constant. What is the half-life period ?

Answer»


Solution :As RATE does not remain CONSTANT with time, it is not a ZERO ORDER reaction. HENCE, we try integrated first order equation, i.e., `k=(2.303)/(t)log""(c_(0))/( c )`
24631.

The rate of dehydration of alcohols to form alkenes depends on ........

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Both the CONCENTRATION of dehydrating AGENT and alcohol
Only on the concentration of alcohol
The concentration of protonated alcohol
Only on the concentration of dehydrating agent.

Solution :The formation of carbocation from the protonated alcohol is the slow step of the reaction and THUS it is the RATE DETERMINING step.
24632.

The rate of decompostion of ozone drops sharply in ………… .

Answer»

ACIDIC MEDIUM
ALKALINE medium
neutral medium
Ether medium

Solution :alkaline medium
24633.

The rate of decomposition of ammonia is found to depend upon the concentration of NH_(3) according to the equation -(d[NH_(3)])/(dt)=(k_(1)[NH_(3)])/(1+k_(2)[NH_(3)]) What will be the order of reaction when (i) concentration of NH_(3) is very high ? (ii) concentration of NH_(3) is very low ?

Answer»

Solution :The given rate law equation can be written as `-(d[NH_(3)])/(DT)=(k_(1))/(1//[NH_(3)]+k_(2))`
(i) If `[NH_(3)]` is very high, `1//[NH_(3)]` becomes negligible `:.-(d[NH_(3)])/(dt)=(k_(1))/(k_(2))=k`
i.e., rate becomes independent of concentration. Hence,it is of zero ORDER.
(ii) If `[NH_(3)]` is very SMALL, `1//[NH_(3)]` will be very large `(gtgtk_(2))`, so that `k_(2)` can be neglected in comparison to `1//[NH_(3)]`. Hence, `-(d[NH_(3)])/(dt)=(k_(1))/(1//[NH_(3)])=k_(1)[NH_(3)]`
Thus, REACTION is of 1st order.
24634.

The rate of decomposition of hydrogen peroxide decreases in presence of

Answer»

Platinum
Iron
`MnO_2`
Glycerine

Answer :D
24635.

The rate of decomposition of ammonia is found to depend upon the concentration of ammonia as : - (d[NH_(3)])/(dt) = (k_(1) [NH_(3)])/(1 + k_(2) [NH_(3)]) which of the following statement is correct ?

Answer»

The reaction is zero ORDER at very lowas WELL as very high `NH_(3)` CONCENTRATION
The reaction is first order at very low as well as very high `NH_(3)` concentration .
The reaction is zero order at very low concentration of `NH_(3)` and is of first order at very high concentration of `NH_(3)` .
The reaction is first order at very low `NH_(3)` concentration and is of zero order at very high `NH_(3)` concentration .

Answer :D
24636.

The rate of decomposition of a gas at a certain temperature is 5.14 and 7.25 in some units for 20% and 5% decomposition respectively. Calculate the order of the reaction.

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ANSWER :2
24637.

The rate of decompositionof a substance increases by a factor 2.25 for 1.5 times increases in concentration of substance at same temperature. Find order of the reaction

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ANSWER :2
24638.

The rate of decomposition for methyl nitrite and ethyl nitrite can be given in terms of rate constant k_(1) and k_(2) respectively. The energy of activation for the two reactions are 152.30 kJ mol^(-1) and 157.7 kg mol^(-1) as well as frequency factors are 10^(13) and 10^(14) respectively for the decomposition of methyl and ethyl nitrite. Calculate the temperature at which rate constant will be same for the two reactions.

Answer»

256 K
354 K
282 K
674 K

Answer :C
24639.

The rate of decomposition for methyl nitrite and ethyl nitrite can be given in terms of rate constant ("in" sec^(-1)) k_(1) "and"k_(2) respectively. The energy of activationsfor the two reactions are 152.30 kJ "mol"^(-1) "and" 157.7 kJ "mol"^(-1) as well as frequency factors are 10^(13)"and" 10^(14) respectively for the decomposition of methyl and ethyl nitrite. Calculate the approx. temperature at which rate constant will be same for the two reactions.

Answer»


ANSWER :282
24640.

The rate of decomposition for methyl nitrite and ethyl nitrite can be given in terms of rate constant ("in" sec^(-1)) K_(1) and K_(2) respectively. The energy of activation for the two reaction are 152.30 kJ mol^(-1) and 157.7 kJ mol^(-1) as well as frequency factor are 10^(13) and 10^(14) respectively for the decomposition of methyl and ethyl nitrite. Calculate the temperature at which rate constant will be same for the two reactions.

Answer»


SOLUTION :N//A
24641.

The rate of decay per second of a radioactive sample

Answer»

proportional to the life time lived by the nucleus
DECREASES with the life time lived
is independent of the life time lived
depends upon the TOTAL number of radioactive NUCLEI present in the sample

SOLUTION :`r = LAMBDA , N ,r = ((0.683)/(tau_(1//2)))N therefore r = ((1)/(t)) n`
24642.

The rate of chemisorption

Answer»

decreases with INCREASE of pressure
is INDEPENDENT of pressure
is MAXIMUM at one atmospheric pressure
increase with increase of pressure

Answer :B
24643.

The rate of constant is numerically the same for 1 order, II order and III order. Select the correct statements, if

Answer»

`[A]LT1,` then `r_(1)gtr_(2)gtr_(3)`
`[A]lt1`, then `r_(1)ltr_(2)ltr_(3)`
`[A]gt1`, then `r_(1)gtr_(2)gtr_(3)`
`[A]=1` then `r_(1)=r_(2)=r_(3)`

Solution :`r_(1)=K.[A]^(1),r_(2)=K.[A]^(2),r_(3)=K.[A]^(3)`
`AtoB^(+)""C`
`C_(0)""0""0`
24644.

The rate constant of a reaction depends on

Answer»

TEMPERATURE
Mass
Weight
Time

Solution :k = `AE^(-E_(a)//RT)` by this equation it is CLEAR that rate CONSTANT of a reaction depends on temperature .
24645.

The rate of chemisorption :

Answer»

is INDEPENDENT of PRESSURE
decreases with INCREASE of pressure
INCREASES with increase of pressure
none of these

Solution :increases with increase of pressure
24646.

The rate of chemical reaction is doubled for every 10^@C rise in temperature because of

Answer»

decrease in the ACTIVATION energy
decrease in the threshold energy
INCREASE in the number of molecular collisions
increase in the number of ACTIVATED molecules

Solution :Rate of REACTION increases because number of activated molecules increases.
24647.

The rate of chemical reaction is directly proportional to

Answer»

active masses of reactants
equlilibrium CONSTANT
active masses of PRODUCTS
PRESSURE

SOLUTION :This is law of mass ACTION.
24648.

The rate of chemical reaction (except zero order)

Answer»

decreases from MOMENT to moment
independent constant throughout
independent of the ORDER of reaction
reamin unchange

SOLUTION :Rate is `(dx)/(dt)=-(d[A])/(dt)`
Where x STANDS for product concentration and [A] stands for REACTANT concentration. It continously decreases with decrease in concentrationof reactant with time
24649.

The rate-of chemical reaction (except zero order):

Answer»

Decreases from MOMENT to moment
Remains CONSTANT, throughout
Independent of the ORDER of REACTION
NONE of the above

Answer :A
24650.

The rate of chemical reaction depends upon

Answer»

TIME
pressure
concentration
All of these

Answer :D