Irreversible Reaction Kinetics of the Aerobic Oxidation of Ascorbic Acid

1985 ◽  
Vol 57 (2) ◽  
pp. 555-558 ◽  
Author(s):  
David Emlyn. Hughes
Keyword(s):  
Ascorbic Acid ◽  
Reaction Kinetics ◽  
Aerobic Oxidation ◽  
Irreversible Reaction ◽  
Kinetics Of

scholarly journals KINETICS OF THE OXIDATION OF VITAMIN C

2012 ◽  
Vol 12 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Sitti Rahmawati ◽  
Bunbun Bundjali
Keyword(s):  
High School ◽  
Ascorbic Acid ◽  
Vitamin C ◽  
Reaction Kinetics ◽  
Senior High School ◽  
School Level ◽  
Acid Oxidation ◽  
High School Level ◽  
Exponential Factor ◽  
Kinetics Of

Vitamin C or ascorbic acid is needed by the human body but it is already damaged by the rise in temperature due to be oxidized to L-dehydroascorbic acid. This research aims to determine the kinetics of oxidation of ascorbic acid due to an increase if temperature (40-80 °C) and to design an ascorbic acid oxidation reaction laboratory module to be applied in the senior high school reaction kinetics curriculum. The determination of the kinetics of the oxidation of ascorbic acid applies the integral and half-change time methods, while the concentration of the remained ascorbic acid in sixty minute intervals is determined by iodimetric titration method. Decomposition of ascorbic acid was measured at 40, 50, 60, 70 and 80 °C. The results of this research indicate that at 40, 50, 60, 70 and 80 °C the kinetics of the oxidation of ascorbic acid is a first-order reaction with rate constants of 4.55 x 10-4, 5.85 x 10-4, 8.4 x 10-4, 1.1 x 10-3 and 1.015 x 10-3 min-1, respectively. Pre-exponential factor or the frequency of collisions is a factor which is a measure of the collision rate. The activation energy and the pre-exponential factor for the oxidation of ascorbic acid were found to be 20.73 kJ.mol-1 and 1.372 min-1. The procedure used in this study was modified into a laboratory module will be applied in the teaching of reaction kinetics at the senior high school level.

Kinetics of Aerobic Oxidation of Ascorbic Acid

1972 ◽  
Vol 61 (4) ◽  
pp. 556-562 ◽  
Author(s):  
S.M. Blaug ◽  
B. Hajratwala
Keyword(s):  
Ascorbic Acid ◽  
Aerobic Oxidation ◽  
Kinetics Of

Impact Of Synthesis Route on the Water Oxidation Kinetics of Hematite Photoanodes

2020 ◽  
Author(s):  
Camilo A. Mesa ◽  
Ludmilla Steier ◽  
Benjamin Moss ◽  
Laia Francàs ◽  
James E. Thorne ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Reaction Kinetics ◽  
Water Oxidation ◽  
Oxidation Kinetics ◽  
Oxidation Reaction ◽  
Charge Accumulation ◽  
Optical Signals ◽  
Current Voltage ◽  
Voltage Performance ◽  
Kinetics Of

<p><i>Operando</i> spectroelectrochemical analysis is used to determine the water oxidation reaction kinetics for hematite photoanodes prepared using four different synthetic procedures. Whilst these photoanodes exhibit very different current / voltage performance, their underlying water oxidation kinetics are found to be almost invariant. Lower photoanode performance was found to correlate with the observation of optical signals indicative of charge accumulation in mid-gap oxygen vacancy states, indicating these states do not contribute directly to water oxidation.</p>

Sign in / Sign up

Export Citation Format

Share Document