The molar mass of copper (Cu) is 63.55 grams per mole (g/mol). This means that 1 mole of copper has a mass of 63.55 grams. To calculate the mass of 14.5 moles of copper, we can use the formula:

Mass = Number of moles × Molar mass

Mass = 14.5 moles × 63.55 g/mol

Mass = 920.48 grams

Therefore, the mass of 14.5 moles of copper is 920.48 grams.