Question

If you start with 512 grams of aluminum and 1147 grams of copper chloride to make aluminum chloride and copper, what is the limiting reagent?2Al + 3CuCl -> 2AlCl3 + 3CuA. AlCl3B. CuClC. AlD. Cu

Answer 1

Chemistry => Stoichiometry => Limiting reactant

The limiting reactant corresponds to the reactant that produces the least amount of moles of products, that is, it will be the reactant that theoretically reacts completely.

To find the limiting reactant we will first calculate the moles of each reactant. For that, we divide the given mass by the respective molar mass of the compounds.

Molar Mass Al = 26.98g/mol

Molar Mass CuCl = 98.999g/mol

Moles Aluminum

`molAl=512g*(1molAl)/(26.98gAl)=19.0molAl`

Moles Copper Chloride

`molCuCl=1147gCuCl*(1molCuCl)/(98.999gCuCl)=11.6molCuCl`

Now, to find the limiting reactant we divide the moles found in each compound between the stoichiometry coefficient from the balanced equation.

So, we will have:

`\begin{gathered} Al\rightarrow(19.0)/(2)=9.50 \\ \\ CuCl\rightarrow(11.6)/(3)=3.87 \end{gathered}`

The compound with the smallest quotient will be the limiting reactant.

So, the limiting reactant will be CuCl

Answer: B. CuCl