A jewelry manufacturer experiments with producing bronze by mixing copper (atomic…
CHEMISTRY · Multi-part · AP · Chemistry · Compound Structure and Properties · Compound Structure and Properties
Problem
A jewelry manufacturer experiments with producing bronze by mixing copper (atomic radius = 128 pm) with varying proportions of tin (atomic radius = 140 pm).
Bronze is historically described as a substitutional alloy in which tin atoms replace copper atoms within the crystalline lattice.
(a) Describe the structural difference between a substitutional alloy and an interstitial alloy at the particulate level.
(b) Using the atomic‐radius information provided, explain—without performing a numerical calculation—why copper and tin are more likely to form a substitutional alloy than an interstitial alloy. In your explanation, refer explicitly to relative atom sizes and the nature of lattice holes.
(c) Bronze can be prepared over a range of tin contents, but beyond roughly 15 atomic % Sn a new, tin-rich phase begins to separate. Propose a particulate-level reason for this limited solubility of Sn in the Cu lattice, even though their radii differ by less than 15 %.