S.L. 437.69 ст. 7a black with the silver silver nitrate used to to dissolve its silver N. the acidified

OBSERVATIONS If the sample contains a large quantity of sulphides (e.g. beans), precipitate of silver sulphide is formed which is filtered together cyanide deposit. The formation of this precipitate causes a loss of solution 0ꞏ02 N, the volume of which must be subtracted from the volume calculate the HCN content. To do this, proceed as follows: Treat the deposit left on the filter with 50 ml of ammonia (3.8) in order the silver cyanide. Wash the residue in dilute ammonia and then determine content. Convert the value obtained into ml of silver nitrate solution 0ꞏ02

The sample’s HCN content may also be determined by titrating ammoniacal filtrate with nitric acid.