• The rate of reaction is defined as

  Rate = −1∆[A] = −1∆[B] = + 1∆[C] = +1∆[D] ?? ∆?? ?? ∆?? ?? ∆???? ∆??

• Average rate: the change in measured concentrations in anyparticular time period

• Instantaneous rate: the change in concentration at any oneparticular time

• Generally, the greater the concentration of reactant molecules,the faster the reaction

• Increasing temperature increases the reaction rate for mostreactions

  Questions 1: Table I displays some data relating to anexperiment 2NO (g) + O2(g) ? 2NO2(g)

  Table 1: Experimental data

  1. 1.1 Why is there a negative sign in equation (1)? Give acorresponding equation for the rate of production of a product.

  2. 1.2 Based on the data provided in Table 1, what is the averagerate of consumption (M/s) for the NO(g) and O2(g) over the first100 seconds? What is the rate of production (M/s) for the product,NO2(g)? (report three rates respectively)

  3. 1.3 Are the three rates you obtained in #2 the same? What is thepotential problem you see if you use rate of consumption/productionto characterize how fast the reaction proceed?

  4. 1.4 How shall we define rate of reaction that will give usunique value, independent of which

  species we are monitoring? Determine the rate of reactionaccordingly for this problem.

Time (s)	[NO] (M)	[O2] (M)	[NO2] (M)
0	2.40	2.0	0
100	1.80	1.70	0.60