In a study of the formation of HI from its elements,H₂(g)+I₂(g)→ 2HI(g) equal amounts of H₂ and I₂ were placed in a container, whichwas then sealed and heated.(a) On one set of axes, sketch concentration vs. time curves for H₂ and HI, and explain how Qchanges as a function of time.(b) Is the value of Qdifferent if [I₂] is plotted instead of [H₂]?

In a study of the decomposition of ammonia on a platinum surface at 856 °C NH31/2 N2 + 3/2 H2 the following data were obtained: NH3], M 2.39x10-3 1.20×103 997 6.00x104 1.50x103 3.00x10-4 1.75x103 seconds Hint: It is not necessary to graph these data. (1) The observed half life for this reaction when the starting concentration is 2.39x10-3 M is s and when the starting concentration is 1.20×10-3 M is s. (2) The average rate of disappearance of NH3 from t= 0 s to t= 997 s is Ms!. (3) The average rate of disappearance of NH3 from t= 997 s to t= 1.50×103 s is M s-l. (4) Based on these data, the rate constant for this | order reaction is M s-1.

In a study of the gas phase decomposition of phosphine at 120 °C PH3(g)1/4 P(g) + 3/2 H2(g) the concentration of PH3 was followed as a function of time. It was found that a graph of In[PH3] versus time in seconds gave a straight line with a slope of -2.38×102s and a y-intercept of -2,47. Based on this plot, the reaction is order in PH3 and the rate constant for the reaction is

1) The rate constant for the gas-phase reaction H2(g) + I2(g) → 2 HI(g) has the value 4.45 x 10-5 mol-1 dm³ s-1. What is the equivalent rate constant in units of molecule-1 cm³ s- 1? 2) The kinetics of the hydrolysis of methyl methanoate, CH3COOCH3, in aqueous solution were investigated by measuring the concentration of the ester after different time intervals. The reaction was found to be first order in the concentration of the ester. Use the data below to determine the rate constant for the reaction (must provide best fit graph). 3600 time, t/s 1800 5400 7200 9000 concentration, c/ (mol dm-3) 0.300 0.191 0.135 0.081 0.055 0.035