Question

The Lassaigne’s extract is boiled with dil HNO$_3$ before testing for halogens because

• A. AgCN is soluble in HNO$_3$
• B. Silver halides are soluble in HNO$_3$
• C. Ag$_2$S is soluble in HNO$_3$
• D. Na$_2$S and NaCN are decomposed by HNO$_3$

Answer 1

Answer: (D)

Na$_2$S and NaCN are decomposed by HNO$_3$

Answer 2

If nitrogen or sulphur is also present in the compound, the sodium fusion extract is f irst boiled with concentrated nitric acid to decompose cyanide or sulphide of sodium during Lassaigne’s test.