No abstract

No abstract

No abstract

Mass-spectrometric measurements have been made of the axial concentrations of the positive ions along premixed, flat flames of H,, 0, and N,, either with or without trace amounts of acetylene added to the unburned gases. In each case the principal positive ion is H 3 0 + , whereas the sole negatively charged species is the free electron. The main reaction governing the concentration of H 3 0 + in the burned gases of such a flame without acetylene added is:However, with acetylene in the burner supplies, chemi-ionisation in a flame's reaction zone produces amounts of H 3 0 + far in excess of those for equilibrium. Thus H 3 0 + disappears via the forward step of (1) in the burned gases, enabling its rate constant to be measured between 1820 and 2400 K. This ion-electron recombination coefficient was found to vary with temperature, T , according to: k , = (3.6 & 0.5)T-2.'*0*7 ion-' ml s-'. The magnitude of k , at 2000 K is (4.2 f 0.6) x ion-' ml s-';theoretical considerations indicate that k , is proportional to T -'.'.

No abstract