Question

In the table, weight gain-time data for the oxidation of some metal at an elevated temperature are tabulated. W (mg/cm Time (min) Data Set 1.90 25 Data Set 2 3.76 75 Data Set 3 6.40 250 (a) Determine whether the oxidation kinetics obey a linear, parabolic, or logarithmic rate expression (b) Now compute W after a time of 3000 min. Part 1 Your answer is partially correct. Try again. The first part of this problem is to establish whether the oxidation kinetics obey linear, parabolic, or logarithmic rates (see Figure 16.26). One way to do this problem is to use trial and error by solving each expression for its K values and seeing if those values are the same regardless of which data sets are used. Here you have three data sets for W and t, so it is possible to write three simultaneous equations. Start by assuming the kinetic rate is parabolic. (a) What are K1 and K2 for data sets 1 and 2? K1 211 K,-T 1 .65 (b) What are K1 and K2 for data sets 2 and 3? K1 1533 K2 2.64 (c) Is the kinetic rate parabolic? (Yes/No) No v

Answer 1

Given Parabti'c Kineh'c rade 2. s 1.9 3.26 7S 6.4250 2. 2. 3.6, = 25 K, + KL. ) Solving ①戶国 13-4: 75 Kl + K2 weJet K'= 0.1472 K-哇.32 (-1.32 Frem dada set 23; te em$6 k,ニ О.ISフ C k2 ~ne not same İn both data set. So, parc-bote Kinehk k,