A research group investigates how atomic-size mismatch affects maximum substitutional…
CHEMISTRY · Multi-part · AP · Chemistry · Compound Structure and Properties · Compound Structure and Properties
Problem
A research group investigates how atomic-size mismatch affects maximum substitutional solid solubility of various elements in fcc copper. Experimental data are summarized below.
Element Atomic radius (pm) Maximum substitutional solubility in Cu (atomic %)
X 125 >95
Y 140 15
Z 150 0.5
A new element W has an atomic radius of 132 pm.
(a) Using the data for X, Y, and Z, describe the relationship between percent radius difference and maximum substitutional solubility in copper.
(b) Estimate the percent radius difference for element W relative to Cu (128 pm).
(c) On the basis of the trend you identified in part (a), predict the approximate maximum substitutional solubility of W in Cu. Clearly justify your prediction.
(d) If metallurgical analysis revealed that W actually exhibits a lower solubility than predicted, propose one factor other than atomic-size mismatch that could account for the discrepancy, and explain its possible effect on alloy formation.