Answer : Mass of copper (Cu) metal obtained = 556.281 g
Solution : Given,
Mass of copper ore = 1 Kg = 1000 g
From the periodic table, the molar mass of copper and copper ore are
Molar mass of copper = 63.546 g/mole
Molar mass of copper ore,
= 342.678 g/mole
First we have to calculate the number of moles of copper ore, 
Moles of
=
=
= 2.918 moles
The balanced chemical reaction is :

From this chemical reaction, we conclude that
2 moles of
gives → 6 moles of Cu
2.918 moles of
gives →
= 8.754 moles
Thus, the Moles of copper (Cu) = 8.754 moles
Now, calculate the Mass of copper (Cu).
Mass of copper (Cu) = Moles of copper (Cu) × Molar mass of copper (Cu)
= 8.757 moles × 63.546 g/moles
= 556.281 g