Question

What is the molarity of ZnCl2 that forms when 25.0 g of zinc completely reacts with CuCl2 according to the following reaction? Assume a final volume of 285 mL .
Zn(s)+CuCl2(aq)→ZnCl2(aq)+Cu(s)

Answer 1

Molarity of $\mathrm{ZnCl}_{2}$ is 1.364 M

Explanation:

Molarity of product Zinc Chloride which is formed when 25.0 g of Zinc completely reacts with copper(II) chloride: $\mathbf{Z n}(\mathbf{s})+\mathbf{C u C l}_{2}(\mathbf{a q}) \rightarrow \mathbf{Z n C l}_{2}(\mathbf{a q})+\mathbf{C u}(\mathbf{s})$

Firstly no of moles of Zn can be obtained from :  

$\text { Moles of } \mathbf{Z n}=\frac{\text { Mass of Zn }}{\text { Molar Mass of Zn }}$, molar mass of Zn = 65.38 g/mol  

hence moles of Zn = 25.0 g / 65.38 g/mol = 0.382 mol.

Now some conversion are needed to be done like:

1 m L = 0.001 L

Volume of solution = 285 mL

Hence 285 mL = 285 × 0.001 L = 0.28 L

Finally Molarity of $\mathrm{ZnCl}_{2}$ can be calculated by:  

Molarity of $\mathrm{ZnCl}_{2}$  = $\frac{\text { number of moles of solute }}{\text { Volume of solution in litres }}$

Molarity = $\frac{\text { 0.382 mol}}{\text { 0.28 L }}$ = 1.364 M.

Answer 2

The molarity of ZnCl2 is equal to 1.33 mol/L.

Mole calculation

To calculate the molarity of the product formed, one must have knowledge of the molar mass of zinc, in order to discover the number of moles that will react, so that:

MMZn = 65.28g/mol

                                              $MM = \frac{m}{mol}$

                                              $65.38 = \frac{25}{mol}$

                                               $mol = 0.38$

Thus, 0.38 mol of zinc reacts to form the products.

As can be seen from the reaction, the ratio of formation of Zn and the required product is 1:1, so 0.38 mol of the product are formed.

Finally, just calculate the number of moles present in 1 liter, so that:

                                         $\frac{0.38mol}{xmol} =\frac{285ml}{1000ml}$

                                           $x = 1.33 M$

So, the molarity of ZnCl2 is equal to 1.33M.

Learn more about mole calculation in: brainly.com/question/2845237