The Reduction of a Solutİon of Sodium Chromate in Hydrdchloric Acid by Methanol

Authors : R.e. SOWDEN

Pages : 0-0

Doi:10.1501/Commub_0000000161

View : 13 | Download : 7

Publication Date : 1980-01-01

Article Type : Research Paper

Abstract :The industrially interesting reduction by methanol of a solution of 0.8M sodium chromate in 6M hydrochloric acid has been investigated thermocalorimetrically. The proposed overall stoichiometric equation z 2Na2CrO4insert ignore into journalissuearticles values(aq); + CH3OHinsert ignore into journalissuearticles values(aq); + 10HClinsert ignore into journalissuearticles values(aq); + II2Oinsert ignore into journalissuearticles values(1); - 2[Crinsert ignore into journalissuearticles values(H2O);4. aj. CJinsert ignore into journalissuearticles values(aq); + 4NaClinsert ignore into journalissuearticles values(aq); + CO2insert ignore into journalissuearticles values(g); is in agreement with experimental observations at 21.2-70.8°C. The molar ratioMeOH insert ignore into journalissuearticles values(consumed);: CrVI insert ignore into journalissuearticles values(reduced);—1:1.98 mol/mol; the meanheat of reaction, AH — -0.759 MJ mol-1; and carbon dioxide gas w as proved to be evolved. The experimentally determined activation energy, E = 28.2 kj mol~1,and the order of reaction with respect to methanol, n = 1.81, appear to be inconsistent with the chro¬mate ester mechanism; an alternative reaction mechanism is suggested.
Keywords : Reduction, Solutİon, Chromate