# Problem: Commercial brass, an alloy of Zn and Cu, reacts with hydrochloric acid as follows:Zn (s) + 2 HCl (aq) → ZnCl 2 (aq) + H2 (g) (Cu does not react with HCl.)When 0.5065 g of a certain brass alloy is reacted with excess HCl, 0.0985 g ZnCl2 is eventually isolated. How could this result be checked without changing the above procedure?

###### FREE Expert Solution

We're being asked to determine how could the result of the reaction be checked without changing the given procedure. We're given the following balanced reaction:

Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) (Cu does not react with HCl.)

First, we need to calculate the amount of zinc needed to produce 0.0985 g ZnCl2.

From the balanced reaction:  1 mole of Zn produces 1 mole of ZnCl2.

mass ZnCl2 (molar mass ZnCl2) → moles ZnCl2 (mole-to-mole comparison) → moles Zn (molar mass Zn) → mass Zn

molar mass of Zn = 65.39 g/mol

molar mass of ZnCl2:

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###### Problem Details

Commercial brass, an alloy of Zn and Cu, reacts with hydrochloric acid as follows:

Zn (s) + 2 HCl (aq) → ZnCl 2 (aq) + H2 (g) (Cu does not react with HCl.)

When 0.5065 g of a certain brass alloy is reacted with excess HCl, 0.0985 g ZnCl2 is eventually isolated. How could this result be checked without changing the above procedure?