Answer
$C_{Cu} $= 1.69 wt%
$C_{Pt} $= 98.31 wt%
Work Step by Step
Given:
5 at% Cu
95 at% Pt
Required:
weight in percent
Solution:
$A_{Cu} = 63.55 g/mol$
$A_{Pt} = 195.08 g/mol$
Using Equation 4.7:
$C_{Cu} = \frac{C_{Cu}A_{Cu}}{C_{Cu}A_{Cu} +C_{Pt}A_{Pt}} \times 100 = \frac{(5)(63.55 g/mol)}{(5)(63.55 g/mol) + (95)(195.08)} \times 100 $= 1.69 wt%
$C_{Pt} =\frac{C_{Pt}A_{Pt}}{C_{Cu}A_{Cu} +C_{Pt}A_{Pt}} \times 100 = \frac{(95)(195.08 g/mol)}{(5)(63.55 g/mol) + (95)(195.08)} \times 100 $= 98.31 wt%