oxidation/reduction

Silver Plated Ornaments

silver ornaments

I have used several different versions of the Silver Mirror or Tollen's Test lab. I am sharing the method that has proven to be the most reliable for me. The solutions should be made fresh, the directions must be followed closely and timing is very important. I like the fact that relatively small amounts of the chemicals are required, but as always you must be vigilant with safety precautions. 

Time required: 

15 minutes of prep time and 20 minutes of class time if you have multiple hoods available for students to use. I only have one hood, so I have another activity for students to complete while two groups rotate through the lab over two 60 minute class periods. 

JCE 91.02—February 2014 Issue Highlights

Journal of Chemical Education February 2014 Cover

Fostering Engagement in Nanotechnology The Feburary 2014 issue of the Journal of Chemical Education is now available online to subscribers at http://pubs.acs.org/toc/jceda8/91/2. The February issue features articles on nanotechnology in the areas of public engagement, instrumentation, and laboratory experiments.

Energizer Lab

Students proceed through a prior knowledge activity, practice creating and using a voltaic cell and use of a model designed to simulate the particulate level activity within a voltaic cell. The teacher checks for student understanding at specific points as groups work together. A discussion follows to help clarify ideas.

Time required: 

About one 60 minute class period for lab and manipulative procedure.

Copper penny with concentrated nitric acid

The reaction of a copper penny (minted pre-1982) and concentrated nitric acid (15 M) is shown. Red-brown nitrogen dioxide is generated and some of the copper dissolves to form a blue solution of copper(II) nitrate.