Question

${\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$is:
A. Black
B. Yellow
C. Orange
D. White

Answer 1

Hint: It is arsenic trisulfide. It also occurs as mineral orpiment, which is used as a pigment called “King’s yellow”. Therefore it is a dark yellow solid which is insoluble in water.

Complete step by step answer:
${\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$(arsenic trisulfide) is an inorganic compound generally insoluble in water. It is a dark yellow solid.
Chemical formula: ${\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$
Molar mass: ${{75\times 2 + 32\times 3 = 246g}}{\text{.mo}}{{\text{l}}^{{\text{ - 1}}}}$
Appearance: Dark yellow crystals
Geometry: Pyramidal
Crystal structure: Monoclinic
The chemical equation involving the process to obtain ${\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$is:
${\text{2As + 3S}} \to {\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$

Option B is correct. ${\text{A}}{{\text{s}}_{\text{2}}}{{\text{S}}_{\text{3}}}$is yellow.

ADDITIONAL INFORMATION: As this compound is less soluble in water its toxicity level is low. Otherwise, if someone comes in contact with this compound it can cause short term health effects to chronic health effects such as skin, liver cancer in humans.

Note:
Arsenic trisulfide is dark yellow in colour. Remember, it is not an orange colour compound. The oxidation number of Arsenic in this compound is ${\text{ + 3}}$. This compound has various applications in different fields. It is used as a tanning agent also.