# Finding the emiprcal formula

• johndoe

## Homework Statement

A metal alloy consists of aluminium and zinc. When a 1.00 g sample of alloy is reacted with excess HCl, 0.0610 g of hydrogen gas forms. Calculate the percent composition of the alloy.

## The Attempt at a Solution

Set up a balanced equation then calculated the relative moles and grams of the elements and compounds

AlZn + HCl -> H2 + AlCl + HZn is the product correct?

If the reaction runs at all, yes, that is the correct product. Whether it will run or not depends on whether AlCl is more "stable" than AlZn. And, of course, you haven't yet balanced the equation.

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AlZn is the formula for a 50/50 alloy. We do not know that is the case, so this formula has to be written in a more general form.

An alloy is a physical mixture, not a chemical compound. Thus, the two substances in your alloy are Al and Zn, not some chemical compound composed of Al and Zn. Thus, you have to consider two separate reactions, the reaction between Al and HCl and the reaction between Zn and HCl.