Microsoft Excel

a) Write a function DERIV(t,x) that returns the first derivative of x vs. t. (use central difference except for the extreme points for which you use forward and backward differences)

b) DERIV, then plot ln(-dc/dt) vs. ln c and finally determine k and n from linear regression.

In Excel for the regression, you can use the function LINEST(y,x), which will return the slope and the intercept. Note that the formula must be entered as an array formula, followed by CTRL+SHIFT+ENTER

Chemical reactions often follow the model: dc -kch dt Where c = concentration, t=time, k = reaction rate, and n = reaction order. Given values of c and dc/dt, k and n can be evaluated by a linear regression of the logarithm of this equation: log (-2) = log k + n loge Use this approach along with the following data to estimate k and n: 10 20 30 40 50 60 3.52 2.48 1.75 1.23 0.87 0.61