adspace


Question 52 - 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?

Answer Posted / kang chuen tat (malaysia - pen

Answer 52 - (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 ?    1 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

how did you spend today

2144


can anyone send me the written test paper of Indian oil corporation ltd. My email id is pratuljakhmola@yahoo.com

4493


Jspl question paper for freshers requirements chemical engineering diploma

1606


can u tel me d question paper of gail?

4208


sir,please give me some exam paper for referance. Thanks & Regards,

2231


In which state sulphur exists at 40 degrees temperature and 40 atmospheric pressure in natural gas having sulphur composition 0.1 ppm?

1752


Can any one send me the sample test papers of IOCL entry exam to be held on 6th july 2008. Also plz send the interview questions that cud probably be asked........i wud be highly obliged if u can send a few test paers and other stuff @ inderjeetd@gmail.com.........Inderpreet

2791


hai....i am chandrika. if anybody having test questions for HAL,HPCL,ONGC,IOL...PLS SEND THE QUES WITH SOLVED ANSWERS TO ME TO MY MAIL ID chandrismiles@yahoo.co.uk

2322


friends....i have been searching the model paper for HPCL officer trainee for chemical eng....tat apptitude section...if u people got any information regarding tat...please send me to my mail...my id is: maruthu.flower@gmail.com...pls send me wtever information u knew....thank u....

2441


hai can anyone send me soft copy of o.p gupta or tell me downloading link please please at saify_0@hotmail.com

2543


which materials can l use if l want to use length wave 680 to 900 in hplc

2085


pls send me model paper of NPCIL for executive trainee. and syllabus of executive trainee 2015.

2855


i need last year question paper of GATE exam of chemical stream.but i failed i geting exam papers.soits humble request to u that if any body found last years GATE exam paper of chemical stream then send it to on this mail address.i shall be thankful to u for this. mail address:- sachin_4255@yahoo.co.in thank you.

3795


i am a student of thapar university final year.can anybody please help me with the exam pattern of the companies:engineers india ltd. ; iocl ; UOP, HPCL. If psbl plz send me the previous years questions on this email id k_arora1987@yahoo.com. i d be really greatful

2457


i am a prefinal year student of polymer engineering .could you please send the latest question papers regarding entrace exam.

2343