a student carries out this chemical reaction in a beaker: Zn+CuCl2-->Cu+ZnCl2 After the reactionhas come to completion, what should the student expect to find in the beaker?

The correct answer is

C. Cu and ZnCl2

Explanation:

I got it correct on PLATO

A. 837 grams of are produced when 12.81 moles of water react with an excess of

Explanation:

The balanced chemical equation is

Mole ratio of is 6 : 4 or 3 : 2

As per the Equation

6 moles of water produces 4 moles of Phosphoric acid

So let us convert  

12.81 moles to moles by using mole ratio and then to mass by  multiplying with molar mass

is produced

Please note:  

Molar mass is the mass of 1 mole of the substance and its unit is g/mol

We find the molar mass by adding the atomic mass of the atoms present in it.

For example contains 3 atoms of H, 1 atom of P and 4 atoms of O

So the molar mass