Example 2
Use Figure 1.1 to determine the instantaneous rate at 3 h.
Solution
The slope of the tangent at 3 h can be determined by drawing a triangle such as the one shown in Figure 1.1, and comparing the ratio of the height of the rise to the run of the length.
Slope = [latex] frac{Rise}{Run} [/latex] = – [latex] frac{ Delta [Reactant]}{Delta t} [/latex] = – [latex] frac{4.5-6.5 M}{4-2 h} [/latex] = – [latex] frac{- 2 M}{2 h} [/latex] = 1 [latex] frac{M}{h} [/latex]
