Explore the question in detail with explanation, related questions, and community discussions.
Golden Spangles is the common name given to Lead(II) chromate (PbCrO₄), an inorganic compound that is well known for its intense yellow color. This substance has historically been used as a pigment due to its brightness and covering power. In older literature and industrial usage, the shiny golden-yellow appearance of lead chromate crystals led to the term “Golden Spangles.”
Chemical Composition:
Formula: PbCrO₄
Elements: Lead (Pb), Chromium (Cr), Oxygen (O)
Appearance: Bright yellow to orange crystalline solid
Formation:
Lead chromate can be obtained by the reaction of lead nitrate solution with potassium chromate solution, forming a yellow precipitate of PbCrO₄:
Pb(NO3)2+K2CrO4 → PbCrO4↓+2KNO3Pb(NO₃)₂ + K₂CrO₄ \;\; \rightarrow \;\; PbCrO₄ \downarrow + 2KNO₃Pb(NO3)2+K2CrO4→PbCrO4↓+2KNO3
Properties:
Insoluble in water but soluble in alkali hydroxides.
Highly colored, giving a vivid golden-yellow hue.
Stable under normal conditions but can darken when exposed to sulfide gases due to formation of PbS.
Applications:
Historically used as a pigment in paints, giving the characteristic chrome yellow color.
Employed in printing inks, plastics, and ceramics.
Although attractive, its use has declined due to toxicity of lead compounds and environmental concerns.
Why Golden Spangles?
The term originates from the bright, sparkling appearance of PbCrO₄ crystals under light. These “spangles” of golden-yellow color made the compound visually distinctive and led to its common industrial nickname.
Golden Spangles = Lead(II) chromate (PbCrO₄)
Synonym: Chrome yellow
Characterized by bright yellow/golden appearance
Used historically as a pigment but now restricted due to toxicity
Therefore, the correct answer is Lead(II) chromate (PbCrO₄).
Discussion
Leave a Comment