Challenge Questions

A reaction A -> B occurs with a first-order rate constant k = 0.05 s−1 at a steady state. The inflow stream contains 2 mol/L of reactant A at a flow rate of 5 L/s. If the reactor is designed to achieve 90% conversion of A, calculate the minimum reactor volume required. 

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Find the Internal Energy at 112 degrees Celsius and 0.65 MPa 
Skill: Bilinear Interpolation


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Part 1: Find the Centroid of the region bounded by the curves y = sinx, y = cosx, x = 0, and x = pi/4. 

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Part 2: Find the volume of the region rotated over the x-axis using the Theorem of Pappus. 

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A hydrocarbon fuel (C₃H₈) is burned in a combustion chamber with excess air. The air is preheated to 400 K, and the combustion products exit at 1800 K. 
Part 1: Calculate the mass of air needed per kg of fuel to maintain a 10% excess air ratio 
Part 2: Find the adiabatic flame temperature assuming complete combustion.

Note: Make sure to include N2 in the Balanced chemical reaction due to its role in the combustion process. 

Answer

Part 1: What is the wavelength in nm of the electromagnetic radiation emitted from the change in energy state of the electron from n = 6 to n = 2. 

Use:
Change in E = (-2.18 x 10^-18J)((1/n(final)^2) + (1/n(initial)^2))

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Part 2: What is the type of electromagnetic radiation that is emitted? If in the visible spectrum, find color. 

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In a chemical reactor, the concentration of a reactant A decreases over time due to a first-order reaction, where the rate of reaction is proportional to the concentration of A. The rate law is given by:
dA/dt = - kA
Where A is the concentration of A (mol/L), k is the rate constant (1/s), and t is time (s).
At time t = 0, the concentration of A is A0.
Question: Determine the concentration of A at any time t. 
Set up a differential equation to complete this task. 

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