InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 87751. |
A reaction rate constant is given by k = 1.2 xx 10^(14) e^(-(25000//RT)) sec^(-1) . It means |
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Answer» log k versus log T will GIVE a straight line with slope as `- 25000` |
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| 87752. |
A reaction proceeds with the energy of activation of 55.3 kcal/mole. If AH of the reaction is 1 kcal, what would be the energy of activation of the reverse reaction? |
| Answer» SOLUTION :54.3kcal | |
| 87753. |
A reaction proceeds in three stages. The first stage is a slow and involves two molecules of reactants. The second and third stage are fast. The overall order of the reaction is |
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Answer» first order |
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| 87754. |
A reaction proceeds in three stages. The first stage is a slow and involves two molecules of reactants .The second and third stage are fast .The overall order of the reaction is : |
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Answer» FIRST order |
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| 87755. |
A reaction proceeds by a two step mechanism A_2underset(k_2)overset(k_1)hArr2A (fast reaction) A+B to Products (slow reaction) What is the rate law for the overallreaction ? |
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Answer» rate `=k[A_2][B]` `k = ([A]^(2))/([A_(2)]) or [A]^(2) = k XX [A_(2)]` or `A = sqrt(k xx [A_(2)]) "" … (i)` Form ` A + B to` Products (slow reaction ) , the rate LAW is :` (dx)/(dt) = k [A] [ B]` Substituting the value of [A] from (i) in (II) , `(dx)/(dt) = "rate" = k sqrt(k xx [ A_(2)]) xx [B]` `= k xx sqrtk xx [A_(2)]^(1//2) xx [ B]= k [A_(2)]^(1//2) xx [B]` |
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| 87756. |
A reaction P to Q is completed 25% in 25 min, 50% completed in 25 min if [P] is halved, 25% completed in 50 min if [P] is doubled. The order of reaction is |
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Answer» 1 `K = (1)/(t){[A]_(0)-[A]}` Case I. `k = (1)/(25) XX (25)/(100) = 10^(-2)` Case II. `k = (1)/(25) xx (1)/(2) {[A]_(0)-[A]}` (as[P] is HALVED) `= (1)/(25) xx (1)/(2) xx (50)/(100) = 10^(-2)` Case III. `k = (1)/(50) xx 2{[A]_(0)-[A]}` `""` (as [P] is doubled ) ` = (1)/(50)k xx 2 xx (25)/(100) = 10^(-2)` As k comes out to be constant, hence the given reaction is of zero order. |
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| 87757. |
(A) Reaction of HI with ter-butylethylether produces ter.butyliodide & ethyl alcohol(R) It follows SN^1reaction |
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Answer» Both (A) and (R) are TRUE and (R) is the CORRECT explanation of (A) |
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| 87758. |
A reactionof firstorderwithrespect to reactantA andsecondorderwithrespectto reactantB. the rate lawforthe reactionis givenby |
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Answer» `"Rate"=K[A][B]^(2)` |
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| 87759. |
(A) Reaction of Cl_(2) with hot and concen -trated NaOH is disproportionation reaction (R ) Oxidation state of chlorine changed from 0"to"-1and+5 |
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Answer» Both (A) and (R ) are true and (R ) is the CORRECT explanation of (A) |
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| 87760. |
A: Reaction of carboxylic acid with hydrazoic acid in the presence of conc. H_(2)SO_(4) to form primary amine is called Schmidt reaction. R: In this reaction isocyanate intermediate is formed. |
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Answer» If both Assertion & REASON are TRUE and the reason is the CORRECT explanation of the assertion, then mark (1). |
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| 87761. |
(A) Reaction of benzaldehyde with formaldehyde in presence of base is crossed Cannizzaro's reaction. (R) Formaldehyde is always oxidized in this reaction because it is better oxidising agent. |
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Answer» Both (A) and (R) are TRUE and (R) is the correct EXPLANATION of (A) |
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| 87762. |
A reaction of aryl diazonium salts that does not involved loss of nitrogen takes place when they react with phenol and aromatic amines. Aryl diazonium ion relatively is weak electrophile but has sufficient reactivity to attack strongly activated aromatic ring. The reaction is known as azo coupling. The coupling of diazonium ions with phenols or other electron rich aromatic compounds is useful commercial reaction as azo compounds are highly coloured and many of them are used as dyes. Coupling between arenediazonium cation and amines takes place most rapidly at pH |
| Answer» Solution :Basic coupling takes place in weakly acidic MEDIUM `(P^(N)=5" to "7)` | |
| 87763. |
A reaction of aryl diazonium salts that does not involved loss of nitrogen takes place when they react with phenol and aromatic amines. Aryl diazonium ion relatively is weak electrophile but has sufficient reactivity to attack strongly activated aromatic ring. The reaction is known as azo coupling. The coupling of diazonium ions with phenols or other electron rich aromatic compounds is useful commercial reaction as azo compounds are highly coloured and many of them are used as dyes. Which of the folllowing is responsible for the colour of diazo compounds ? |
| Answer» Solution :`-N=N-` group | |
| 87764. |
A reaction occurs spontaneously if : |
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Answer» `TtriangleSgttriangleH and TRIANGLEH` is +ve and `TRIANGLES is -ve` |
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| 87765. |
A reaction is spontaneous if free energy change DeltaG , for the reaction is negative . The question arises, how we can explain , the spontaneous of reversible reaction taking the example of dissociation equilibrium N_2O_4 hArr 2NO_2(g) the variation of free energy with the fractionof N_2O_4 dissociated under standard conditions is shown in the figure below. When 1 mole of N_2O_4 changes into the equilibrium mixture the volume of DeltaG^@ is |
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Answer» 0.84 kJ |
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| 87766. |
A reaction mixture for the combustion of SO_2 was prepared by opening a stopcockconnecting two separate chambers, one having a volume of 2.125 litres filled with SO_2 at 0.75 atm and the other having 1.5 litres volume filled with oxygen at 0.50 atm, both gases were at 80^@C.(i) What were the mole fractions of SO_2 and O_2in the mixture, and the total pressure?(ii) If the mixture was passed over a catalyst that promoted the formation of SO_3and was then returned to the original two connected vessels, what were the mole fractions in the final mixture and what was the final total pressure? Assume that the conversion of SO_2 is complete to the extent of the availability of O_2 |
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Answer» SOLUTION :(i) 0.68,0.32, 0.64 ATM (II) 0.06, 0.94,0.44 atm |
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| 87767. |
A reaction is spontaneous if free energy change DeltaG , for the reaction is negative . The question arises, how we can explain , the spontaneous of reversible reaction taking the example of dissociation equilibrium N_2O_4 hArr 2NO_2(g) the variation of free energy with the fractionof N_2O_4 dissociated under standard conditions is shown in the figure below. The standard free energy change for the conversion of 1 mole of N_2O_4 into 2 moles of NO_2 is |
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Answer» 5.40 KJ =5.40 kJ |
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| 87768. |
Areaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is (i) doubled (ii) reduced to half ? |
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Answer» SOLUTION :For a second order reaction, `R=k[A]^(2)` where A is a reactant. (i) If the concentration of A is doubled then, `R_(1)=k[2A]^(2)=4K[A]^(2)` `THEREFORE (R_(1))/(R)=(4k[A]^(2))/(k[A]^(2))=4` `therefore ` RATE will increase 4 time original rate. (ii) When the concentration of A is reduced to half, `R_(2)=k[(A)/(2)]^(2)=(1)/(4)k[A]^(2)` `therefore (R_(2))/(R)=(1//4xxk[a]^(2))/(k[A]^(2))=(1)/(4)` `therefore ` Rate will reduce to `1//4` th initial value. |
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| 87769. |
A reaction is spontaneous at low temperature but non-spontaneous at high temperature. Which of the following is true for the reaction |
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Answer» `DeltaH gt 0, DeltaS gt 0` |
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| 87770. |
A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is (i) doubled (ii) reduced to half? |
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Answer» SOLUTION :Rate `=k[A]^(2)=KA^(2)`. [Let [A] be REPRESENTED by a] If `[A]=2a, " rate"=k((a)/(2))^(2)=(1)/(4)ka^(2)`. The rate becomes one-fourth. |
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| 87771. |
A reaction is secondorder with respect to a reactant . How is the rate of reaction affected if the concentration of the reactant is : (i) doubled (ii) reduced to half. |
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Answer» Solution :(i) Reaction is SECOND ORDER with respect to the reactant `:. "Rate" = K [ A] ^2 = ka ^2` When [A]=2a Rate = `k (2a)^2=4 ka ^2` = 4 times Therefore , when concentration of the reactant is doubled the rate will become 4 times (ii) when `[A]= 1/2 a` Rate `=k(1/2a)^2=1/4ka^2=1/4k` Therefore , rate will be reduced to one - fourthe the initial rate. |
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| 87772. |
A reaction is said to be first order if it's rate is proportional to the concentration of reactant Let us consider a reaction A(g) rarr B(g) + c(g) At t=0 a 00 At time t a-x xx The rate of reaction is given by the expression (dx)/(dt)=k(a-x) and integrated rate equation for a given reaction is represted as k=1/t l n(a/(a-x)) where a=initial concentration and (a-x) = concentration of A after time t. Consider a reaction A(g) rarr 3B(g) + 2C(g) with rate constant 1.386xx10^(-2)min^(-1) starting with 2 moles of A in 12.5 litre vessel initially if reaction is allowed to take place at constant pressure and at allowed to take place at constant pressure and at 298 K then find the concentration of B after 100 min. |
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Answer» `0.04` MIN |
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| 87773. |
A reaction is said to be first order if it's rate is proportional to the concentration of reactant Let us consider a reaction A(g) rarr B(g) + c(g) At t=0 a 00 At time t a-x xx The rate of reaction is given by the expression (dx)/(dt)=k(a-x) and integrated rate equation for a given reaction is represted as k=1/t l n(a/(a-x)) where a=initial concentration and (a-x) = concentration of A after time t. Thermal decomposition of compound X is a first order reaction If 75% of X is decompossed in 100 min, how long will it take for 90% of the compound to decompose? [Given :log 2=0.30] |
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Answer» 190 MIN |
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| 87774. |
A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is (i) Doubled (ii) reduced to half ? |
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Answer» Solution :(i) ` r = K[A]^(2) rArr r = k[2A]^(2) rArr r4k[A]^(2)` Rate increases by four times. (ii) ` r = k[A]^(2)` `r = k[(A)/(2)]^(2) rArr = (1)/(4) k[A]^(2)`. Rate increases by four times. |
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| 87775. |
A reaction is represented by A overset(k_1)rarr B(slow ) and A+B overset(k_2)rarrC(fast) where k_1and k_2are the ratge constants of two steps. The rate of production of C will be given by |
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Answer» `k_1[A][B]` |
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| 87776. |
A reaction is of the first order reaction to A and is of second order relative to B .what will be the effect on rateif the concentration of A and B are doubled |
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Answer» Velocity REMAINS constant r' = k `[2A][2B]^(2) = 8k [A] [B]^(2) ` or r' = 8r . |
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| 87777. |
A reaction is of second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is reduced to half ? What is the unit of rate constant of such a reaction ? |
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Answer» SOLUTION :RATE=`K[A]^2` Unit of `k=(MOL L^(-1))/S=k(mol^(-1))^2` `k=mol^(-1) L S^(-1)` |
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| 87778. |
A reaction is of second order in A and first order in B. How is the rate affected when the concentration of both A and B is doubled ? |
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Answer» SOLUTION :A reaction is SECOND order in A and first order in B When concentration of both A and B is doubled then, Rate `= k[2A]^(2)[2B]=8k [A]^(2)[B]=8` (INITIAL rate) This shows that rate will increase 8 times to the initial rate. |
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| 87779. |
A reaction is of second order with respect to a reactant. How is its rate affected if the concentration of the reactant is (i) doubled (ii) reduced to half? |
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Answer» SOLUTION :RAT `=k[R]^(2)` (i) If R is INCREASED to 2R, then Rate `=k[2R]^(2)=4k[R]^(2)` Thus, the rate increases four times. (II) If R is reduced to `(R )/(2)`, then Rate `=k[(R )/(2)]^(2)= (1)/(4) k[R]^(2)` Thus, the rate is reduced to one-fourth. |
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| 87780. |
A reaction is of second order in A and first order in B. How is the rate affected on increasing the concentration of A three times ? |
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Answer» Solution :A reaction is second order in A and first order in B When the concentration of A is increased three TIMES, (i.e) 3A, then Rate `= K[3A]^(2)[B]` `= 9k [A]^(2)[B]=0` (initial rate) This shows the rate will INCREASE 9 times to the initial rate. |
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| 87781. |
A reaction is of first order in reactant A and of second order in reactant B. How is the rate of this reaction affected when (i) the concentration of B alone is increased to three times. (ii) the concentrations of A as well as B are doubled? |
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Answer» Solution :`(dx)/(DT)= k[A][B]^(2) " Let "[A]=a, [B]=b, (dx)/(dt)=k.a.b^(2)` (i) When the concentration of B is increased to THREE TIMES, `(dx)/(dt)= ka(3b)^(2) or (dx)/(dt)=9kab^(2)` Thus the rate increase 9 times. (ii) When the concentration of A as well as B are DOUBLED, `(dx)/(dt)= k(2a)(2b)^(2)" or "(dx)/(dt)=k.2a.4b^(2) " or "(dx)/(dt)=8kab^(2)` Thus the rate increases 8 times. |
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| 87782. |
A reaction is of first order in reactant A and of second order in reactant B. How is the rate of this reaction affected when (i) the concentration of B alone is increased to three times, (ii) the concentrations of A as well as B are doubled ? |
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Answer» Solution :According to QUESTION the given reaction is rate EQUATION `:.` Rate = `k[A]^(1)[B]^(2)` (i) When concentration of B is tripled it means conc. Of B becomes 3 times Rate `= k[A][3B]^(2)` `:.` The rate of reaction becomes 9 times (ii) When conc. of A and B both is DOUBLED, then conc. of A becomes 2A and that of B becomes 2B. `:.` Rate `= k[2A][2B]^(2)` `= 8k[A][B]^(2)` Rate of the reaction becomes 8 times. |
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| 87783. |
A reaction is firt order in A and second order in B. |
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Answer» Solution :(i) Write the difference RATE equation . (ii)How is the rate affected on increasing the concentration of B three times ? (iii)How is the rate affected when the concentration of both A and B are doubled ? (i) `(dx)/(DT)=K[A]^1[B]^2` (ii) If concentration .B. is triple them the rate will become 9 times . (IV) When concentrationof both A and B are doubled , then the rate will become 8 times . |
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| 87784. |
A reaction is of first order in reactant A and of second order in reactant B. How is the rate of reaction affected when (i) concentration of B alone is increased to three times (ii) the concentration of A as well mass B is doubled ? |
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Answer» |
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| 87785. |
A reaction is first order with respect to the reactant A and Second roder with respect to the reactant B in a reaction. A + B to Product. (i) Write the differential rate equation. (ii) How is rate of reaction affected on increasing the concentration of B by 2 times. |
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Answer» Solution :(i) ` - (DX)/(DT) = k[A]^(1)[B]^(2)` (ii) ` - (dx)/(dt) = k[A][2B]^(2), (dx)/(dt) = 4k[A][B]^(2)` Rate of reaction INCREASES by four TIMES when concentration of B increases by 2 times. |
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| 87786. |
A reaction is first order w.r.t reactant A as well as w.r.t. B. Give the rate law. Also give one point of difference between average rate and instantaneous rate. |
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Answer» SOLUTION :RATE law `"rate = "k[A][B]` Difference between AVERAGE and instantaneous rate Average rate is equal to change in CONCENTRATION of reactants or products divided by the time taken for that change to occur. Instantaneous rate the rate of a reaction at a particular INSTANT. |
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| 87787. |
A reaction is first order with respect to the reactant A and second order with respect to the reactant B in a reaction A+Bto product How is the rate of the reaction affected on increasing tile concentration of B by two times. |
| Answer» SOLUTION :On increasing the concentration of B by two times the RATE of the REACTION increases by FOUR times. | |
| 87788. |
A reaction is first order with respect to the reactant A and second order with respect to the reactant B in a reaction A+Bto product Write the differential rate equation. |
| Answer» SOLUTION :`(DX)/(dx)=K[A][B]^2" "(dx)/(dt)=-K[A][B]^2` | |
| 87789. |
A reaction is first order with respect to reactant A and second order with respect to reactant B in a reaction A+Brarr product. i) Write the differential rate equation. ii) How is the rate of the reaction affected on increasing the concentration of B by two times? |
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Answer» Solution :i) The DIFFERENTIAL rate equation is `d[R]//dt=k[A][B]^(2)` ii) The rate increases by 4 TIMES by increasing the CONCENTRATIO B by 2 times. |
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| 87790. |
Reaction is first order in A and second in B. Write the different rate equation. |
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Answer» Solution :The differential rate EQUATION will be `(-d[R])/(DT)=K[A][B]^(2)` |
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| 87791. |
A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is the rte affected on increasing the concentration of B three times? (iii) How is the rate affected when concentrations of both A and B are doubled? |
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Answer» Solution :(i) `(dx)/(DT)=k[A][B]^(2)." Let"[A]=a and [B]=b`. Thus, `(dx)/(dt)=k ab^(2)`. (ii) If [B] is tripled, RATE `=k a(3b)^(2)=9kab^(2)`. The rate increases 9 times. (iii) If both [A] and [B] are doubled, Rate `=k(2a)(2B)^(2)=8 k ab^(2)`. The rate increases 8 times. |
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| 87792. |
A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is rate affected on increasing the concentration of B three times ? (iii) How is rate affected when the concentration of both A and B are doubled ? |
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Answer» Solution :(i) rate ` = - (DX)/(DT) = k[A]^(1) [B]^(2)` (ii)rate ` = k[A]^(!) [3B]^(2) = 9k[A]^(1) [B]^(2)`. Rate increases by 9 TIMES. (iii) `r = k[2A]^(1) [2B]^(2) = 8K [A}^(1) [B]^(2)` . Rate increases by 8 times. |
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| 87793. |
A reaction is first order in A and second order in B. (i) Write the differential rate equation. (ii) How is the rate affected on increasing the concentration of B three times ? (iii) How is the rate affected when the concentrations of both A and B are doubled ? |
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Answer» SOLUTION :(i) `(DX)/(dt) = k[A]^(1) [B]^(2)` (ii) If concentration of .B. is TRIPLED, then the rate will become 9 TIMES. (iii) When concentration of both A and B are doubled, then the rate will become 8 times. |
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| 87794. |
A reaction is first order in A and second order in B. (i) Write differential rate equation. (ii) How is the rate affected on increasing the concentration of B three times ? (iii) How is the rate affected when concentration of both A and B is doubled ? |
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Answer» Solution :(i) `(DX)/(DT)=k[A][B]^(2).` (ii) Rate `=k" ab"^(2)` If [B] is TRIPLED, Rate `=ka(3" b")^(2)=9" k ab"^(2)=9" times."` (iii) If both [A] and [B] are DOUBLED, Rate `=k(2" a")(2" b")^(2)=8" k ab"^(2)=8" times."` |
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| 87795. |
A reaction is first order in A and second order in B. (i) Write differential rate equation. (ii) How is rate affected when concentrated of B is tripled ? (iii) How is rate affected when concentration of both A and B is doubled ? |
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Answer» Solution :(a) A + B = Products. (i) The reaction is of Ist order with respect to A. Rate w.r.t. `[A] = k[A]` it is of SECOND order w.r.t. B. Rate w.r.t. `[B] = k[B]^(2)` `:.` Overall rate of reaction `= k[A][B]^(2)` `:. (DX)/(dt) = k[A][B]^(2)` (ii) When the concentration of B is tripled. `r^(2) = k[A][3B]^(2)`. `=9K[A][B]^(2)` `:.` Rate becomes 9 times. (iii) If the concentration of A and B is doubled, then `r = k[2A][2B]^(2)` `= 8k[A][B]^(2)` `:.` Rate becomes 8 times. |
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| 87796. |
A reaction is first order in A and second order in B. How the rate is affected (a) on increasing concentration of B three times and (b) on increasing concentration of both A and B twice ? |
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Answer» SOLUTION :Rateis given as rate `=K[A][B]^(2)` (a) If concentration of B is increaseed three times, NEW rate `=K[A][3B]^(2)` `9K[A][B]^(2)` Hence rate is increased by `9` times (b) If concentration of both A and B are doubled, `"new rate"=K[2A][2B]^(2)` `8K[A][B]^(2)` Hence rate is increased by `8` times |
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| 87797. |
Reaction is first order in A and second in B. How is the rate affected when the concentrations of both A and B are doubled ? |
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Answer» Solution :When the concentrations of both A and B are doubled `(-d[R])/(DT)=k[A][B]^(2)` `=k[2A][2B]^(2)` `= 8.k[A][B]^(2)` `THEREFORE` The RATE of reaction will increase 8 TIMES. |
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| 87798. |
Reaction is first order in A and second in B. How is the rate affected on increasing the concentration of B three times ? |
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Answer» Solution :If the concentration of B is increased three TIMES, then `(-d[R])/(DT)=k[A][3B]^(2)` `=9.k[A][3B]^(2)` `THEREFORE` The rate of reaction will increase 9 times. |
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| 87799. |
A reaction is catalysed by H^(+) ion, and in the rate law the dependence of rate is of first order with respect to the concentration of H^(+) ions, in presence of HA rate constant is 2xx10^(-3)"min"^(-1) and in presence of HB rate constant is 1xx10^(-10"min"^(-1). HA and HB have relative strength as : |
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Answer» `0.5` |
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| 87800. |
A reaction is catalysed by.X. Here .X. |
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Answer» DECREASES the rate CONSTANT of reaction |
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