The salt used for performing bead test in qualitative inorganic analysis is:
A
$$Na(NH_{4})HPO_{4}.4H_{2}O$$
B
$$FeSO_{4}(NH_{4})_{2}SO_{6}.6H_{2}O$$
C
$$K_{2}SO_{4}.Al_{2}(S_{4})_{3}.24H_{2}O$$
Correct option is C. $$Na(NH_{4})HPO_{4}.4H_{2}O$$
Microcosmic salt, $$Na(NH_4)HPO_4⋅\;4H_2O$$ is used for performing bead test in inorganic qualitative analysis for the detection of coloured ions.
Hence option (C) is correct.