the production of thymoquinone from thymol and carvacrol
the production of thymoquinone from thymol and carvacrol
the production of thymoquinone from thymol and carvacrol
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APPENDIX A<br />
DETERMINATION OF HYDROGEN PEROXIDE<br />
CONCENTRATION<br />
This method describes <strong>the</strong> determination <strong>of</strong> hydrogen peroxide concentration in<br />
an aqueous solution. The chemical background is <strong>the</strong> reaction <strong>of</strong> potassium<br />
permanganate with hydrogen peroxide in acidic medium according to <strong>the</strong> following<br />
equation:<br />
2 KMnO4 + 5 H2O2 + 4 H2SO4 → 2 KHSO4 + 2 MnSO4 + 8 H2O + 5 O2<br />
The procedure can be carried out when using titration equipment<br />
An exactly weighed sample <strong>of</strong> <strong>the</strong> H2O2 containing solution is added to 50 ml 2.5<br />
M sulphuric acid in a flask. The sample is titrated with 0.02 M st<strong>and</strong>ard potassium<br />
permanganate solution while mixing vigorously. By using manual titration, titrate until<br />
a pale pink coloration persists for a while. The content <strong>of</strong> hydrogen peroxide in <strong>the</strong><br />
solution is calculated <strong>from</strong> <strong>the</strong> consumption <strong>of</strong> KMNO4 as seen below.<br />
H2O2 in solution (mol/ml) = 0.02 (mol/lt) KMnO4 x consumed KMnO4 (ml) x (5/2)<br />
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