[{"from": "human", "value": "Provide a brief overview of this molecule. [N][=Branch1][C][=O][O-1].[K+1]"}, {"from": "gpt", "value": "The molecule is a chemical compound of potassium and nitrite ions. It is used as a food preservative and in the manufacturing of heat transfer salts. Nitrite is a toxic compound known to cause methemoglobinemia. (L1137, L1616)"}]