The density of copper is 8.95g/cm3 and the density of zinc is 7.14 g/cm3, A sample of a Cu-Zn is 80.5 percent Cu and 19.5 percent Zn What is the density of the alloy?
They probably expect you to compute a "weighted mean" density that is 80.5% of the copper density PLUS 19.5% of the zinc density. However, in the real world, a slightly different value is possible. The intramolecular forces and atom spacing in alloys of metals that dissolve in one another, as in this case, can behave in strange ways.
To find the density of the alloy, we can use a weighted average based on the percentages of each element.
Step 1: Convert the percentages to decimal form.
The percentage of copper is 80.5%, which is 0.805 in decimal form.
The percentage of zinc is 19.5%, which is 0.195 in decimal form.
Step 2: Calculate the weighted average.
Density of alloy = (density of copper * percentage of copper) + (density of zinc * percentage of zinc)
Density of alloy = (8.95 g/cm^3 * 0.805) + (7.14 g/cm^3 * 0.195)
Step 3: Calculate the result.
Density of alloy = 7.21275 g/cm^3 + 1.3933 g/cm^3
Density of alloy = 8.60605 g/cm^3
Therefore, the density of the alloy is approximately 8.61 g/cm^3.