(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

This is an example from a book. I am having trouble in substituting the numbers to get the given result.

2. Relevant equations

The bar notation is to indicate the operating point. The subscript A is for the reactant A (which reacts and becomes product B in a A->B reaction). The subscript i stands for the input. So [tex]c_{A_i}[/tex] means the concentration of A entering the reactor.

f_{c}is the flow rate of the coolant

T_{ci}is the temperature of the coolant going in

T_{c}is the temperature of the coolant going out

f is the flow rate of the reactant going in

T_{i}is the temperature of the reactant going in

c_{Ai}is the concentration of the reactant going in

T is the temperature of the reactant going out

c_{A}is the concentration of the reactant going out

3. The attempt at a solution

My problem is that when I plug in the values, I don't get 2.07 for [tex]\tau_1[/tex]. I first assumed that [tex]\bar{f} = f= 1.3364[/tex] and [tex]\bar{T}_{\bar{c}_A} = 678.9[/tex]. But I got [tex]\tau_1 = 0.5148[/tex].

I assumed that my [tex]\bar{f}[/tex] was correct, so I set [tex]\tau_1=2.07[/tex] and rearranged the equation to solve for [tex]\bar{T}_{\bar{c}_A}[/tex].

[tex]\bar{T}_{\bar{c}_A} = -\frac{E}{R}(ln(\frac{1-\frac{\tau_1 \bar{f}}{V}}{2\tau_1 k_o}))^{-1}[/tex] . . . (2)

When I do that I got [tex]\bar{T}_{\bar{c}_A} = 631[/tex], which doesn't match any of the given temperature. So I thought [tex]\bar{f}[/tex] might be 0.8771. And I got [tex]\bar{T}_{\bar{c}_A} = 633[/tex], which still doesn't match any number.

I have tried some other equations but I couldn't get any result to match. Since I don't have a background in studying chemical reactions, I was suspecting that there is something fundamental that I am missing here.

Do you know how the author got 2.07 for [tex]\tau_1[/tex]?

- Thank you.

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# Homework Help: Constants in chemcial reaction

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