Final answer:
To find the number of moles of copper in 28.5 grams of copper, divide the mass of copper by its molar mass of 63.54 g/mol, yielding approximately 0.448 moles.
Step-by-step explanation:
To calculate the number of moles of copper in 28.5 grams of copper, we use the molar mass of copper and Avogadro's number.
The atomic mass of copper (Cu) is approximately 63.54 g/mol. The number of moles of any substance can be found by dividing the mass of the substance by its molar mass.
To find the number of moles of copper in 28.5 grams, we divide 28.5 grams by the molar mass of copper:
Number of moles = Mass of Cu / Molar mass of Cu
Number of moles = 28.5 g / 63.54 g/mol
Number of moles ≈ 0.448 mol
Thus, there are approximately 0.448 moles of copper in 28.5 grams of copper.