REACTION ENGINEERING - EXAMPLE 13.3 : The half-life for first order reaction could be described in the differential equation dC / dt = -kC where k is a constant, C is concentration and t is time. (a) Find the equation of C as a function of t. (b) Find the half life for such reaction or the time required to reduce 50 % of the initial concentration, where k = 0.139 per minute. (c) When the initial concentration Co is 16 mol / cubic metre, how long does the reaction required to achieve the final concentration of 1 mol / cubic metre?
REACTION ENGINEERING - ANSWER 13.3 : (a) dC / dt = -kC, dC / C = -k dt. Integrate both sides gives ln C - ln Co = ln (C / Co) = -kt, C = Co exp (-kt). (b) When C / Co = 0.5, t = [ ln (C / Co) ] / (-k) = [ ln (0.5) ] / (-0.139) = 4.9867 minutes. (c) Step 1 : 16 to 8 mol per cubic metre. Step 2 : 8 to 4. Step 3 : 4 to 2. Step 4 : 2 to 1. Each step takes t minutes. There are 4 steps needed from 16 to 1 mol / cubic metre or 4t = 19.9468 minutes. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.
Is This Answer Correct ? | 0 Yes | 0 No |
all subject of chemical engg
what is the discharge pressure formula, for calculating discharge pressure?
THERMODYNAMIC - EXAMPLE 10.2 : A cylinder with a movable piston contains 0.1 mole of a monoatomic ideal gas. The piston moves through state a, b and c. The heat Q, changes from state c to a is + 685 J. The work W, changes from state c to a is - 120 J. The work, W performed from state a to b then to c is 75 J. By using the first law of thermodynamic, U = Q + W where U is the internal energy : (a) Determine the change in internal energy between states a and c. (b) Is heat added or removed from the gas when the gas is taken along the path abc? (c) Calculate the heat added or removed when the gas is taken along the path abc?
How can you prevent bridging in a dilute phase pneumatic conveying system?
Question 90 - In the calculation of the growth of bacteria, absorbance, A in spectrophotometry is used. According to Beer-Lambert Law, A = e x l x c where A is the absorbance of the solution (no unit), l is the distance of light travels through the solution (in cm), e is the molar absorptivity or the molar extinction coefficient [ in L / (mol.cm) ]. For a particular solute and fixed path length : As / Ao = Cs / Co where Ao is the observed signal for a known concentration Co, and As is the observed signal for a sample concentration Cs. (a) For a cell concentration of 560 cells / mL, a spectrophotometre gives an absorbance reading of 1.0. A mixture of concentration 3600000 cells / mL can be diluted in several operations, with each operation having a dilution of 1:20. How many dilutions should be made so that the concentration of this mixture can be calculated within a range of A = 0.0 to 1.0. (b) In another experiment, a sample tube of 1 cm in width is used. Let A = 0.06 and e = 0.0012 ml / (cell.cm). Find the cell concentration of the sample.
What is the use of gear pumps in motor?
What is the wet bulb globe temperature (wbgt)?
what is first order of reaction?
What is difference between overall heat transfer coefficient & individual heat transfer coefficient?
How can you estimate a gas flow based on two pressure measurements?
Explain how is waste heat boilers categorized?
PLZ ANYONE SEND ME PLACEMENT PAPERS OF I.O.C.L MY ID---- gaurav.nitw.5609@gmailcom