Answer to Question #240000 in General Chemistry for sarah

Question

Magnesium ribbon reacts with hydrochloric acid to produce hydrogen gas

and magnesium chloride. Describe how this reaction could be used to

determine the relative atomic mass of magnesium.   

Answer 1

In this experiment, students react magnesium ribbon with dilute hydrochloric acid to produce hydrogen gas. They can then use the measured volume of hydrogen gas produced and the mass of magnesium to calculate the mass of magnesium required to produce one mole of hydrogen molecules. From this, students can deduce the relative atomic mass of magnesium.

This is a class experiment suitable for students who already have a reasonable understanding of the mole concept, and are at least beginning to use chemical equations to perform calculations.

Timing will depend on the adequacy of access to top-pan balances, and the skill with which students can use the balance to sufficient accuracy. Including the time taken by the teacher to demonstrate the procedure, and allowing an average of five minutes for each student to weigh their magnesium ribbon, a total of 45 minutes should be adequate for the class to obtain and record their results.