Determination of the molar masses of metals

Principle

A piece of metal is weighed and placed in the insert of the reaction cylinder, whereafter an acid is added to the cylinder through the three-way valve until it is about half full. The metal is made to react with the acid by lowering the insert. The gas syringe connected to the reaction cylinder is used to collect the hydrogen which is generated. The mass of the metal and the volume of the hydrogen generated are used to calculate the desired molar mass. The reaction can also be used to determine the valency of the metal.

Benefits

•  Accurate determination of molar mass by application of the ideal gas law´
• Simple implementation and fast measurement results

Tasks

Determine the molar mass of zinc.

Learning objectives

• Molar mass
• Molar volume
• Ideal gas laws
• Valency of metals