Estimation of Hydrazine and its Derivatives with Iodine cyanide and Bromine cyanide

Department of Chemistry, Panjab University, Chandigarh

Received 26 September 1971

Iodine cyanide and bromine cyanide react quantitatively at \({p}\)H 4.6--5.0 and 4.8--5.3 respectively with water soluble salts of hydrazine, phenylhydrazine, benzylhydrazine and chloral hydrazine in the molar ratio 2 : 1 and with acetylhydrazine, 1 : 1 methylphenyl- hydrazine and acid salts of 1 : 1 dimethyl-, 1 : 1 diethyl- and  \({p}\)-tolyl-hydrazines in the molar ratio 1 : 1. Hydroxylamine reacts with these oxidants in the molar ratio 2 : 1 at  \({p}\)H 3.6--4.0 and 6.7-7.2 respectively. The hydrazines are oxidised to nitrogen or substituted tetrazenes. Hydrazine hydrate, phenylhydrazine, chloralhydrazine, 1 : 1 methylphenylhydrazine and benzalazine have been estimated with iodine cyanide potentiometrically in glacial acetic acid and 1 : 1 acetic acid-acetic anhydride mixture, keeping solutions molar with respect to sodium acetate. These hydrazines react in the molar ratios 1 : 1 in the former and 2 : 1 in the latter media except for hydrazine hydrate which consumes only one equivalent of the oxidant in both the media. The titrations are simple, accurate and reversible.