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) 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) B only
(2) A and B both
(3) Neither A nor B
(4) A only
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)
(2)
(3)
(4)
If a first-order reaction reaches 60% completion within 60 minutes, approximately how much time would it take for the same reaction to reach 50% completion? (log 4=0.60, log 5=0.69)
1. 50 min
2. 45 min
3. 60 min
4. 30 min
For the reaction 2A + B 3C + D which of the following does not express the reaction rate ?
(1)
(2)
(3)
(4)
The units of rate constant and rate of reaction are same for:
1. First order reaction
2. Second order reaction
3. Third order reaction
4. Zero order reaction
The rate constant is given as \(K = 1.2 \times 10^3~mol^{-1} L^{-1} s^{-1}\), and the activation energy is \(E_a = 2.0 \times 10^2 ~kJ mol^{-1}\). As temperature T approaches infinity, what is the value of the pre-exponential factor (A)?
1. \(2.0 \times 10^2 \mathrm{~mol}^{-1} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\)
2. \(1.2 \times 10^3 \mathrm{~mol}^{-1} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\)
3. \(3.3 \times 10^3 \mathrm{~mol}^{-1} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\)
4. \(2.4 \times 10^3 \mathrm{~mol}^{-1} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\)
The effect of a catalyst in a chemical reaction is to change the
1. Acivation energy.
2. Equilibrium concentration.
3. Heat of reaction.
4. Final products.
When the concentration of reactant was made 4 times rate of reaction becomes 8 times. The order of reaction with respect to that reactant is
1. 2
2. 3
3. 1
4. 1.5
The bromination of acetone that occurs in acid solution is represented by this equation.
These kinetic data were obtained for given reaction concentrations.
Initial concentrations, M
0.30 0.05 0.05
0.30 0.10 0.05
0.30 0.10 0.10
0.40 0.05 0.20
Initial rate, disappearance of Br2, Ms-1
5.7X10-5
5.7X10-5
1.2X10-4
3.1X10-4
Based on these data, the rate equation is
1. Rate = k [CH3COCH3] [H+]
2. Rate = k [CH=COCH3][Br2]
3. Rate = k [CH3COCH3][Br2][H+]2
4. Rate = k [CH3COCH3][Br2][H+]
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) 1000 K
(2)
(3) 2000K
(4)