1. Tardigrade
  2. Question
  3. Chemistry
  4. The Lassaigne's extract is boiled with conc. HNO3 while testing for halogens. By doing so it

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The Lassaigne's extract is boiled with conc. $HNO_3$ while testing for halogens. By doing so it

AIPMTAIPMT 2011Organic Chemistry – Some Basic Principles and Techniques

Solution:

Na$_2$S and NaCN, if present in the extract, will be
decomposed to H$_2$S and HCN by HNO$_3$ .
NaCN + HN$O_3$ $\rightarrow$ NaN$O_3$ + HCN
Na$_2$S + 2HNO$_3$ $\rightarrow$ 2NaN$O_3$ + H$_2$S
These will escape from the solution and will not
interfere with the test for halogens.