Question

White metal is an alloy of

• A. Li & Mg
• B. Li & Pb
• C. Pb & Sn
• D. Pb & Al

Hint:

"White metal" most commonly refers to alloys based on tin or lead, often with other metals like copper and antimony. Remember the common compositions associated with this term, particularly lead and tin.

Answer 1

The Correct Option is C

White metal is a term that can refer to several different alloys depending on the context.
However, the most common and historically significant "white metal" alloy is **Babbitt metal**.
Babbitt metal is primarily an alloy of **tin (Sn)**, with smaller amounts of other metals like **copper (Cu)** and **antimony (Sb)**.
Lead (Pb) can also be a major component in some variations of Babbitt metal, especially cheaper grades.
Looking at the options provided:
Option (A) Li & Mg: This alloy is known for being lightweight and is used in aerospace applications, but it's not typically referred to as "white metal".

Option (B) Li & Pb: Alloys of lithium and lead are used in some specialized applications, but this is not the standard composition of "white metal".

Option (C) Pb & Sn: An alloy of lead (Pb) and tin (Sn) is a common type of white metal, particularly in the context of solders and some bearing materials (though often with antimony and copper added for strength and hardness in bearings).
This fits the description of a common "white metal" alloy.

Option (D) Pb & Al: Alloys of lead and aluminum are used in some bearing applications, but this specific binary alloy is not the primary association with the term "white metal".
Given the common usage of "white metal" to refer to lead-tin based alloys (often with other additions), option (C) is the most appropriate answer among the choices.
It's worth noting that the term "white metal" can be ambiguous and might sometimes refer to other whitish-silvery alloys.
However, in the context of common alloys, lead and tin are strongly associated with this term.