Question

ignition temperature of sodium​

Answer 1

Experiments in determining the ignition temperatures of pure sodium ; metal, technical sodium metal and technical potassium metal were carried out ; under the following conditions: (1) slow heating in air at a rate of 1.5to 2 and ; 2.5 to 4 deg min; (2) puffing the alkali metal in an experimental oven heated to ; the ignition temperature in air; and (3) heating the alkali metal to the ignition ; temperature in argon with subsequent burning in air or in oxygen. With slow ; heating in air the ignition temperature varied from 437 to 462 deg K at a heating ; rate of 1.5 to 2 deg /s, and from 405 to 420 deg C at a heating rate of 2.5 to 4 ; deg /s. Slow heating of potassium metal at a rate of 2.5 to 4 deg /s leads to ; vigorous oxidation at 260 to 270 deg C, but ignition does not take place. On ; puffing the alkali metal in a preheated oven, ignition of technical and pure ; sodium metals takes place at 390 to 400 deg C, and of potassium metal at 450 to ; 460 deg C. The ignition time is 40 to 60 seconds after puffing the metal in the ; oven. On first heating the metal in argon the ignition temperatures varied from ; 334 to 339 deg C for sodium metal with air flow, from 418 to 428 deg C for ; potassium metal with air flow, and from 285 to 293 deg C for sodium metal with an ; oxygen atmosphere. Secondary ignition of sodium metal in air, whose burning was ; stopped by the passage of argon, takes place at 90 to l50 deg C. Thus the ; temperature of the secondary ignition of sodium is significantly below that of ; the primary ignition. (SJR);

Answer 2

The ignition temperature of sodium in air depends on the area of surface exposed: vapor ignites at room temperature; droplets at about 250°F; an agitated pool at 400°F. In the absence of moisture and hydrogen, the reaction is insignificant