Question

copper was one of the earliest metals used by humans, because it can be prepared from a wide variety of copper minerals, such as cuprite (cu₂o), chalcocite (cu₂s), and malachite cu₂co₃(oh)₂. balance the following reactions for converting these minerals into copper metal. place a coefficient in each gray box.
1st attempt
part 1 (1 point)
cu₂o(s)+ c(s) → cu(s)+ co₂(g)
part 2 (1 point)
cu₂o(s) + cu₂s(s) → cu(s)+ so₂(g)
part 3 (1 point)
cu₂co₃(oh)₂(s) → cuo(s)+ co₂(g)+ h₂o(g)

Explanation:

Step1: Balance carbon and oxygen in Part 1

For the reaction $\mathrm{Cu_2O}(s)+\mathrm{C}(s)
ightarrow\mathrm{Cu}(s)+\mathrm{CO_2}(g)$, to balance the oxygen atoms, we need 2 moles of $\mathrm{Cu_2O}$ and 1 mole of $\mathrm{C}$ to get 4 moles of $\mathrm{Cu}$ and 1 mole of $\mathrm{CO_2}$. So the balanced equation is $2\mathrm{Cu_2O}(s)+\mathrm{C}(s)
ightarrow4\mathrm{Cu}(s)+\mathrm{CO_2}(g)$.

Step2: Balance sulfur and copper in Part 2

For the reaction $\mathrm{Cu_2O}(s)+\mathrm{Cu_2S}(s)
ightarrow\mathrm{Cu}(s)+\mathrm{SO_2}(g)$, first balance the sulfur. Then adjust the copper atoms. The balanced equation is $2\mathrm{Cu_2O}(s)+\mathrm{Cu_2S}(s)
ightarrow6\mathrm{Cu}(s)+\mathrm{SO_2}(g)$.

Step3: Balance copper, carbon, hydrogen and oxygen in Part 3

For the reaction $\mathrm{Cu_2CO_3(OH)_2}(s)
ightarrow\mathrm{CuO}(s)+\mathrm{CO_2}(g)+\mathrm{H_2O}(g)$, we can see that 1 mole of $\mathrm{Cu_2CO_3(OH)_2}$ decomposes to 2 moles of $\mathrm{CuO}$, 1 mole of $\mathrm{CO_2}$ and 1 mole of $\mathrm{H_2O}$. So the balanced equation is $\mathrm{Cu_2CO_3(OH)_2}(s)
ightarrow2\mathrm{CuO}(s)+\mathrm{CO_2}(g)+\mathrm{H_2O}(g)$.

Answer:

Part 1: 2, 1, 4, 1
Part 2: 2, 1, 6, 1
Part 3: 1, 2, 1, 1