Sodium hydroxide is added to a cylinder of aluminum nitrate, precipitating out aluminum hydroxide. When additional base is added, the precipitate dissolves. The reactions can then be reversed with the ...

Safety: Weigh the zinc dust in a hood. Heat sodium hydroxide and zinc dust using the ventilation grating in Chem 140 or in a chemical fume hood. Use tongs to handle the pennies. Use caution with hot ...