2007-09-03 18:43:42 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
-KCN on dissolution in water gets ionized into H+ ion and CN- ion. On boiling the CN- ion can get hydrolysed and hence the toxicity of KCN can get reduced.
The change in colour of indicator in presence of acids is due to change in pH of the solution. In general the indicators are pH sensitive and change colour with the change in pH.
2007-09-03 20:15:34 · answer #1 · answered by sb 7 · 0⤊ 0⤋
The toxicity of KCN is due to the CN- ion. On boiling, it hydrolyses and is thus destroyed and hence the toxicity reduces.
Indicators change colour as their structure is pH sensitive and the structure (and consequently the colour) of the indicator changes with the pH.
2007-09-07 04:12:31 · answer #2 · answered by Rajendra J 1 · 0⤊ 0⤋
The key is the word "hydrolysis". The cyanide ion is gradually broken down on boiling to methanoic acid and ammonia.
2007-09-03 19:43:35 · answer #3 · answered by Gervald F 7 · 1⤊ 0⤋