BiH3 is prepared by the redistribution of methylbismuthine (BiH2Me): :3 BiH2Me → 2 BiH3 + BiMe3 The required BiH2Me, which is also thermally unstable, is generated by reduction of
methylbismuth dichloride, BiCl2Me with
LiAlH4. As suggested by the behavior of
SbH3, BiH3 is unstable and decomposes to its constituent elements according to the following equation: :2 BiH3 → 3 H2 + 2 Bi (Δ
H(gas) = −278 kJ/mol) The methodology used for detection of
arsenic ("
Marsh test") can also be used to detect BiH3. This test relies on the
thermal decomposition of these trihydrides to the metallic mirrors of reduced As, Sb, and Bi. These deposits can be further distinguished by their distinctive solubility characteristics: arsenic dissolves in
NaOCl, antimony dissolves in
ammonium polysulfide, and bismuth resists both reagents. ==Uses and safety considerations==