ana bad2at mozahret kinetics
w ana bzakr l msa2el kan 3andy mo$kla x l mas2lten dol
ana m3aya l answeres bat3tehom lakn m$ fahmaha
ya ret ely fahmaha ytahkrm w y4r7ha
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(1998)
if the reaction A ---->B was zero order in nature & concentration of B was 0.0 at begining of thereaction & was 0.1 M after 10 minutes , the intial concentration of A was 0.1 M then :
a)the rate const of the reaction = ..............
b) t 1/2 = ...............
c) the time required for the concentration of A to be zero = .........
d) the concentration of B after 75 minutes = ............
e) the time required for 90% completion of the reaction=.........
the answer
a) kt = x
k =0.1 /10 = 0.01 M\min
b) t1/2 = a/ 2k = 0.1 / (2 x 0.01 ) = 5 mins
c) x = 0.1
a = zero
t = 10 mins
d) kt = x
0.01 x 75 = x
x = 0.75
e) x = 0.90 * 0.1 = 0.09
kt = x
t = 0.09 / 0.01 = 9 mins
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( 2000 )
the decomposition of hydrogen reroxide obeys 1st order kinetic reaction according to the following reaction :
2H2O2 ____> 2H2O + O2
the volume of oxygen produced at the end of the reation was found to be 50 ml O2 .
if the volume of O2 measured after 15 mins was found to be 15 ml ,
calculate the rate const for the reaction & its t 1/2
the answer
a = 50
a- x = 35
kt = ln ( a/ a-x )
k = (1/15) * ln (50/35)
k = 0.023 1/min
t1/2 = 0.693 / k = 0.693 / 0.023
= 29.14 min