(ii) At elevated temperatures, nitrogen dioxide decomposes to nitric oxide and molecular oxygen: 2NO2(g) → 2NO(g) + O2(g) The change in concentration of NO2 with time at 300 °C is given below: t (s) 100 200 300 400 500 [NO:J/10-3 (mol dm-3) 8.0 5.6 4.3 3.5 2.9 2.5 By appropriate plotting of the data and use of this graph: (a) verify that this reaction is second order with respect to NO2; (b) determine the rate constant for this reaction.

In a study of the gas phase decomposition of nitrogen dioxide at 383 °C NO₂(g) →→→NO(g) + ½ O₂(g) the concentration of NO₂ was followed as a function of time. It was found that a graph of 1/[NO₂] versus time in seconds gave a straight line with a slope of 0.815 M-¹ s¹ and a y-intercept of 11.5 M-¹. Based on this plot, the reaction is [ ✓order in NO₂ and the rate constant for the reaction is M-¹ S-¹.

8. (15 marks) A reaction is written as A(g) At 298 K, k₁ =0.21 s.1. k.₁=5×10 Pa¹·s¹. B(g) + C(g). k-1 As the temperature increased from 298 K to 310 K, the values of k₁ and k., are doubled (denoted as k2 and K.2). (1) Calculate the rate constant k at 298K; (2) Calculate the activation energy of both forward and reverse reactions; (3) Calculate AH and AU for the reaction at 298K; (4) Calculate the reaction time at the whole pressure reaching to 152 kPa. The initial pressure of A(g) is 100 kPa and the reaction temperature is 298 K.

11:27 2NH4+ (aq) + HCO3- (aq) The reaction is first order with respect to urea, and first order overall with a rate constant of 4.28 x 10^(-4)s^(-1) a. Write the rate law for this reaction. b. If the reaction begins with an initial urea concentration of 0.500 M, what will the concentration of urea in the solution be after 2500 s? C) Calculate the half life of this reaction. d. At what time (+) will the concentration of urea be 0.020 M? O □

Suppose the reduction of nitric oxide proceeds by the following mechanism: step elementary reaction rate constant 1 H,(g) + 2 NO(g) → N,0(g) + H,0(g) k1 2 H2(9) + N,0(9) → N2(9) + H,O(g) Suppose also k, «k,. That is, the first step is much slower than the second. Write the balanced chemical equation for the overall chemical reaction: Write the experimentally- observable rate law for the overall chemical reaction. rate = k U Note: your answer should not contain the concentrations of any intermediates. Express the rate constant k for the overall chemical reaction in terms of k1, k2, and (if necessary) the rate constants k.1 and k-2 for k = the reverse of the two elementary reactions in the mechanism.

2C4H6(g) → C8H12(g) At high temperatures, the compound C4H6 (1,3-butadiene) reacts according to the equation above. The rate of the reaction was studied at 625 K in a rigid reaction vessel. Two different trials, each shown with a different starting concentration, were carried out. The data were plotted in three different ways, as shown below. (a) For trial 1, calculate the initial pressure, in atm, in the vessel at 625 K. Assume that initially all  the gas present in the vessel is C4H6. (Hint-this is a gas law problem from chemistry last year) (b) Use the data plotted in the graphs to determine the order of the reaction with respect to C4H6. (c) The initial rate of the reaction in trial 1 is 0.0010 mol/(L *s). Calculate the rate constant, k, for  the reaction at 625 K.

Please help

Good evening. I hope you are well. My chemistry question is attached to this message as a JPG.

3. The following reaction: A' (a) + B (ag + C (an)→ G* (ae) +2 H ) AH = -250 kJ There are two proposed mechanism: Mechanism 1 A' () + B aa) AB' a) + D (a) Step 1 AB" (a) (fast) + E (a) + Hm → G' sae) + H ) + D² (n) Step 2 (slow) Step 3 E (agi+ C (a) (fast) Mechanism 2: Step 1 AB' (a) A' (an) + B (ag) AB' (a) + C ja) (fast) Step 2 + G' (a) + 2 H() (slow) The reactions was determined to have the following rate law: r= k[A'][B] a) Which of the two proposed mechanisms is valid? Explain. b) List any reaction intermediates: catalysts: c) What is a rate determining step? d) If the activation energy for the overall forward reaction is 150 kJ, sketch the potential energy diagram for the above reaction; showing the overall reaction, the reaction mechanism, labelling the AHu, AHy, Eapu, Eag, reaction intermediates, and activated complex. rvs fwd drvs/

For which reaction below would you expect to have the largest orientation factor (p)?(a) N2(g) + 3 H2(g) → 2 NH3(g)(b) O3(g) + O(g) → 2 O2(g)(c) CH3OH(l) + HCl(g) → CH3Cl(l) + H2O(l)(d) 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)