Concentrated Sulphuric Acid is used to test for the identity of halides in solid halides
Study the observations on adding acid to the identified reaction products
A few drops of conc sulphuric acid added to a solid halide and a white steamy vapour observed
Steamy fume was HCl and halide was chloride
A few drops of conc sulphuric acid added to a solid halide and a white steamy vapour and brown vapour observed
Steamy fumes were HBr, BR2 (SO2) so the halide was a bromide
A few drops of conc sulphuric acid added to a solid halide and white steamy fumes, black solid, purple vapour and yellow solid noted. The reaction was vigorous.
HI, I2, S (H2S) were all noted because halide was iodide