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