Consider the reaction 2CuCl2 + 4KI → 2CuI + 4KCl + I2. If 4 moles of CuCl2 react with 4 moles of KI, what is the limiting reactant?

CuCl2

KI

CuI

I2

The limiting reactant is KI (answer B)

Explanation

Limiting reactant is the reactant that is completely consumed during reaction. KI is the limiting reactant since it is completely consumed.

By use of mole ratio determine the number of moles produced by each reactant.

that is the mole ration of CUCL2:CUl is 2:2 therefore 4 moles of CUC2 react to produce 4 moles of CUl.

The moles ratio of KI: CUI is 4:2 therefore 4 moles of Kl react to produce 4 x2/4 = 2 moles of CUl.

Since 4 moles of KI react to produce 2 moles of CUI while 4 moles CUCl2 react to produce 4 moles of CUI KI is the limiting reagent