Question

Dinitrogen pentoxide (N205) decomposes as follows to nitrogen dioxide and nitrogen trioxide: N205(8) —NO2(g) +NO3(g) Calculate the average rate of the reaction between consecutive measurement times in the following table. Time (s) [N205] (molecules/cm3) 0.00 1.605x1012 1.35 1.521x1012 2.70 1.455x1012 4.05 1.401x1012 5.40 1.357x1012 3rd attempt Part 1 (1 point) Feedback See Periodic Table Express every answer to two significant figures. Rate 1 = 2.55 x 10 11 molecules/cms) Part 2 (1 point) * Feedback Rate 2 = molecules/(cmºs) Part 3 (1 point) * Feedback Rate 3 = molecules/cms) Part 4 (1 point) X Feedback See Hint Rate 4 = molecules/cms)

Answer 1

Answer -

Given,

Time (s)	[N2O5] (molecules/cm3)
0.00	1.605 * 1012
1.35	1.521 * 1012
2.70	1.455 * 1012
4.05	1.401 * 1012
5.40	1.357 * 1012

N2O5 (g) $\rightarrow$ NO2 (g) + NO3 (g)

Average rate of reation between consecutive measurement times = ?

We know that,

Average rate = (C2 - C1) / (t2- t1)

where,

C2 and C1 are concentration at t2 and t1 respectively.

Part 1 -

Average rate between 0s to 1.35s,

Average rate = (1.521 * 1012 - 1.605 * 1012) / (1.35s- 0s)

Average rate = - 6.2 * 1010 molecules/cm3.s [ANSWER]

Part 2 -

Average rate between1.35s to 2.70s,

Average rate = (1.455 * 1012 - 1.521 * 1012) / (2.70s -1.35s)

Average rate = - 4.9 * 1010 molecules/cm3.s [ANSWER]

Part 3 -

Average rate between 2.70s to 4.05s,

Average rate = (1.401 * 1012 - 1.455 * 1012) / (4.05s - 2.70s)

Average rate = - 4 * 1010 molecules/cm3.s [ANSWER]

Part 4 -

Average rate between 4.05s to 5.40s,

Average rate = (1.357 * 1012 - 1.401 * 1012) / (5.40s - 4.05s)

Average rate = - 3.26 * 1010 molecules/cm3.s [ANSWER]