Poly(2-chloroaniline) was synthesized by chemical oxidative polymerization method using different inorganic acid dopants such as HCl, H2SO4, and HClO4. The effects of the dopants on the physical and electrical properties of the prepared polymers are well studied. The electrical conductivity of the prepared polymers was correlated with the dopant acids used in polymerization. The electrical conductivity of the polymers was found thermally activated and increases linearly with the evolution of temperature from 20 to 90 degrees C. Chemoresistive gas sensors were fabricated using prepared poly(2-chloroaniline) and their sensing evaluation was carried out against different concentrations of ammonia gas steps from 1 to 300ppm. The polymers present a linear increase in their resistances when exposed to different concentrations of ammonia gas.