to solve this we must know the molar mass of the copper(II) fluoride dihydrate and molar mass of copper metal
the molar mass of copper(II) fluoride dihydrate is 137.573 g/mol .
molar mass of copper 63.456 g/mol
mass copper metal = 4.15 g copper(II) fluoride dihydrate ( 1 mol copper(II) fluoride dihydrate / 137.573 g copper(II) fluoride dihydrate) ( 1 mol copper / 1 mol copper(II) fluoride dihydrate) ( 63.456 g copper / 1 mol copper)
mass copper metal =1.914 g copper metal
