Chemical Kinetics · Question 47

For an endothermic reaction, energy of activation is Ea and enthalpy of reaction is H (both of these in kJ/mol). Minimum value of Ea will be

1. less than H
2. equal to H
3. more than H
4. equal to zero

For the reaction N2O5(g) 2NO2(g) + 12O2(g) the value of rate of disappearance of N2O5 is given as 6.25 10-3 mol L-1 s-1. The rate of formation of NO2 and O2 is given respectively as

1. 6.25 10-3 mol L-1 s-1 and 6.25 10-3 mol L-1 s-1
2. 1.25 10-2 mol L-1 s-1 and 3.125 10-3 mol L-1 s-1
3. 6.25 10-3 mol L-1 s-1 and 3.125 10-3 mol L-1 s-1
4. 1.25 10-2 mol L-1 s-1 and 6.25 10-3 mol L-1 s-1

During the kinetic study of the reaction, 2A + B C + D, following results were obtained array|l|l|l|l| Run & [A]/ mol L-1 & [B]/ mol L-1 & Initial rate of formation \ & & & of D/ mol L-1 min-1 \ I. & 0.1 & 0.1 & 6.0 10-3 \ II. & 0.3 & 0.2 & 7.2 10-2 \ III. & 0.3 & 0.4 & 2.88 10-1 \ IV. & 0.4 & 0.1 & 2.40 10-2 \ array Based on the above data which one of the following is correct?

1. Rate = k[A]2[B]
2. Rate = k[A][B]
3. Rate = k[A]2[B]2
4. Rate = k[A][B]2

For the reaction, N2 + 3H2 2NH3, if d[NH3]dt = 2 10-4 mol L-1 s-1, the value of -d[H2]dt would be

1. 4 10-4 mol L-1 s-1
2. 6 10-4 mol L-1 s-1
3. 1 10-4 mol L-1 s-1
4. 3 10-4 mol L-1 s-1

In the reaction, BrO-3(aq) + 5Br-(aq) + 6H+ 3Br2(l) + 3H2O(l). The rate of appearance of bromine (Br2) is related to rate of disappearance of bromide ions as

1. d[Br2]dt = - 53 d[Br-]dt
2. d[Br2]dt = 53 d[Br-]dt
3. d[Br2]dt = 35 d[Br-]dt
4. d[Br2]dt = - 35 d[Br-]dt

Half-life period of a first order reaction is 1386 s. The specific rate constant of the reaction is

1. 0.5 10-2 s-1
2. 0.5 10-3 s-1
3. 5.0 10-2 s-1
4. 5.0 10-3 s-1

For the reaction A + B products, it is observed that (i) on doubling the initial concentration of A only, the rate of reaction is also doubled and (ii) on doubling the initial concentration of both A and B, there is a change by a factor of 8 in the rate of the reaction. The rate of this reaction is given by

1. rate = k[A]2[B]2
2. rate = k[A][B]2
3. rate = k[A][B]
4. rate = k[A]2[B]

The rate constants k1 and k2 for two different reactions are 1016 e-2000/T and 1015 e-1000/T, respectively. The temperature at which k1 = k2 is

1. 2000 K
2. 10002.303 K
3. 1000 K
4. 20002.303 K

The bromination of acetone that occurs in acid solution is represented by this equation. CH3COCH3(aq) + Br2(aq) CH3COCH2Br(aq) + H+(aq) + Br-(aq) These kinetic data were obtained for given reaction concentrations. array|c|c|c|c| [CH3COCH3], M & [Br2], M & [H+], M & Initial rate, disappearance of Br2, M s-1 \ 0.30 & 0.05 & 0.05 & 5.7 10-5 \ 0.30 & 0.10 & 0.05 & 5.7 10-5 \ 0.30 & 0.10 & 0.10 & 1.2 10-4 \ 0.40 & 0.05 & 0.20 & 3.1 10-4 \ array Based on these data, the rate equation is

1. Rate = k[CH3COCH3][Br2][H+]2
2. Rate = k[CH3COCH3][Br2][H+]
3. Rate = k[CH3COCH3][H+]
4. Rate = k[CH3COCH3][Br2]

If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately (log 4 = 0.60, log 5 = 0.70)

1. 45 minutes
2. 60 minutes
3. 40 minutes
4. 50 minutes