Forensic Medicine General 26bf707d Fatal dose of KCN is ? A 50 - 60 mg B 120 -130 mg C 180 -190 mg D 280 - 300 mg High-Yield Explanation Ans. is 'd' i.e., 280 - 300 mg Fatal dose of hydrocyanic acid in the pure form is 50 - 60 mg while as sodium or potassium cyanide is 200 - 300 mg.