The Arrhenius Theory of acids and bases The theory Acids are substances which produce hydrogen ions in solution. Bases are substances which produce hydroxide ions in solution. HBr------>H+ + Br- since HBr is capable of producing H+ it is an acid Solution The Arrhenius Theory of acids and bases The theory Acids are substances which produce hydrogen ions in solution. Bases are substances which produce hydroxide ions in solution. HBr------>H+ + Br- since HBr is capable of producing H+ it is an acid.