Question

2 moles of zinc react with a cupric chloride solution containing 6.032 ×10^{22}formula unit of CuCl_ {2} .calculate the mole of copper obtained

Answer 1

Answer:

According to balanced equation 1 mole of Zinc requires 1 mole of cupric chloride to give 1 mole of copper. When two mole of zinc reacts with 1 mole of cupric chloride even then one mole of copper is obtained because copper chloride gets exhausted and excess zinc remains as it is.

Answer 2

Answer:

Zn +  CuCl2 ---------->  ZnCl2 + Cu

There 1 mole of Zn will react with 1 mole of CuCl2 to give 1 mole of Cu.

From the question we have 2 moles of zinc, and  

CuCl2 has 6.023x10^22 formula units(calculate its moles)

If       6.023x10^23 (avagadro's constant) = 1 mole

then, 6.023x10^22                       =  1 mole x 6.023 x10^22/6.023x10^23

                                                    =  1 mole x 10^22/10^23

                                                    = 1 mole x 10^-1

                                                     =  0.1 moles

Find the limiting factor as not all the Zinc will react with the cupric chloride:

Since 1 mole of zinc requires 1 mole of CuCl2 to give 1 mole of copper, while in this case there is only 0.1 moles of CuCl2, then CuCl2 is the limiting factor and is what we use for the calculation as follows:

If 1 mole of CuCl2 gives 1 mole of Cu.

Then how much  will 0.1 mole of CuCl2 give = 1mole x 0.1 mole/1mole

                                                                      = 0.1 moles

Therefore moles of Cu obtained is 0.1 moles

Hope it helps u !!