Abstract
The propagation of reaction front in acids (CH_3COOH) aqueous solution sodium hydroxide (NaOH) aqueous solution has been investigated using Hele-Shaw cell. The reaction front didn't have any acute angled protuberances which were appeared during chemical reaction with common Rayleigh Taylor instability. In this case, some semicylindrical protuberances were formed at the reaction front due to the generation of salt fmger between sodium acetate aqueous solution and NaOH solution. There were three mass transfer modes which had the stable reaction front, unstable reaction front with salt finger and unstable reaction front with Rayleigh Taylor instability and salt finger.
