1. The problem statement, all variables and given/known data Reference the Cu-Zr phase diagram. If you make the alloy CuZr and heat it to 300°C, what percentage of the material will be Cu10Zr7 and what percentage of the material will be CuZr2? 2. Relevant equations Phase diagram attached. 3. The attempt at a solution I used the lever rule. I called the alpha phase Cu10Zr7 and the beta phase CuZr2. In terms of atomic percent Zr, I have C0=0.5, Cα=0.41, and Cβ=0.665. Then the atomic percent alpha phase is (Cβ-C0)/(Cβ-Cα) which is 64.7 percent. The atomic percent beta is (C0-Cα)/(Cβ-Cα) which is 35.3 percent. So I have 64.7% Cu10Zr7 and 35.3% CuZr2.