Question

The following two reactions are possible methods for refining copper in the final step of a smelting process, i.e., getting pure copper (Cu) from copper ores found in rocks. Calculate the theoretical atom economy for each reaction. a. 2 CuO(s) + C(s) → 2 Cu(s) + CO2(g) = % b. CuO(s) + CO(g) → Cu(s) + CO2(g) = %

Answer 1

Answer: a) 74%

b) 59%

Step-by-step explanation:

Atom economy gives how much desired product is obtained compared to amount of starting materials.

`\text {Atom economy}=\frac{\text {molecular weight of desired product}}{\text {molecular weight of all products}}* 100%`

For reaction a:

`2CuO(s)+C(s)\rightarrow 2Cu(s)+CO_2(g)`

`\text {atom economy of copper}=\frac{\text {molecular weight of desired product}}{\text {molecular weight of all products}}* 100%`

`\text {atom economy of copper}=(2* 63.5)/(2* 63.5+12+2* 16)* 100%=74\%`

For reaction b:

`CuO(s)+CO(g)\rightarrow Cu(s)+CO_2(g)`

`\text {atom economy of copper}=\frac{\text {molecular weight of desired product}}{\text {molecular weight of all products}}* 100%`

`\text {atom economy of copper}=(63.5)/(2* 63.5+12+2* 16)* 100%=59\%`

Thus atom economy for reaction a is 74% and reaction b is 59%.