Chemical Kinetics · Question 50

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

In a first-order reaction A B, if k is rate constant and initial concentration of the reactant A is 0.5 M, then the half-life is

1. 2k
2. 2k 0.5
3. 2k
4. 0.6930.5k

The reaction of hydrogen and iodine monochloride is given as: H2(g) + 2ICl(g) 2HCl(g) + I2(g) This reaction is of first order with respect to H2(g) and ICl(g). The following mechanisms were proposed. Mechanism A: H2(g) + 2ICl(g) 2HCl(g) + I2(g) Mechanism B: H2(g) + ICl(g) HCl(g) + HI(g); slow HI(g) + ICl(g) HCl(g) + I2(g); fast Which of the above mechanism(s) can be consistent with the given information about the reaction?

1. A and B both
2. Neither A nor B
3. A only
4. B only

Consider the reaction : N2(g) + 3H2(g) 2NH3(g) The equality relationship between d[NH3]dt and - d[H2]dt is

1. d[NH3]dt = - d[H2]dt
2. d[NH3]dt = - 13 d[H2]dt
3. + d[NH3]dt = - 23 d[H2]dt
4. + d[NH3]dt = - 32 d[H2]dt