A 28.20 g galvanized steel washer with copper coating is treated with nitric acid. The copper coating is completely removed by reaction with nitric acid and the mass of the washer is now 26.52 g. The washer has an outer diameter D = 45.0 mm, an inner diameter d = 9.0 mm, and a thickness h = 3.0 mm. Copper has density of 8.96 g/cm3.
1. What is the mass of copper coating (in gram)?
2. What is the total volume of copper coating (in mm3, 1cm3 = 1000 mm3)?
3. What is the surface area of the washer (in mm3)? Surface area can be calculated with the following equation: SA= ph(D+d)+(1/2)p(D2-d2)(use 3.1416 for p value)
4. Calculate the thickness of the copper coating (in mm) using the equation
V = (SA) ×(coating thickness)
5. If a single layer of copper atom is 0.270 nm thick (atomic radius of copper = 0.135 nm), how many layers of copper atoms are in the galvanized coating?