Jones, A couple thoughts.
(1) Is it possible to collect the evolved gas without burning it? Can you use a plastic tube to release the gas under an inverted water filled container?
(2) Kansius said the reaction can be carried out to completion, using up all the water. Can you do this and check the residue to see if it is salt or lye?
Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
