Question

What is the total number of moles of nacl formed when 2 moles of na2cro4 react completely?

Answer 1

the balanced chemical equation for the above reaction is as follows;
2Na₂CrO₄ + 2HCl ---> Na₂Cr₂O₇ + 2NaCl + H₂O
stoichiometry of Na₂CrO₄ to NaCl is 2:2
the amount of moles of Na₂CrO₄ reacted is equal to the number of moles of NaCl produced.
We are told that Na₂CrO₄ reacts completely, this means that this is the limiting reactant , amount of product forms depends on amount of limiting reactant present.
When 2 mol of Na₂CrO₄ is used up , according to stoichiometry number of NaCl moles formed are equal to that.
Therefore number of NaCl moles formed - 2 mol

Answer 2

Na2CrO4  react  with  PbCl2  to  form  PbcrO4  +2 NaCl

the  total  number  of  moles  of  nacl  when 2 Na2crO4  react   completely    is  calculated  by  use  of  reacting  ration  between   Na2CrO4  and  NaCl  which  is  1:2  

therefore  the  moles  of   Nacl  is =   2  x2   =  4  moles