Apologia Chemistry: White Powder Update

Two of the kids were able to finish The White Powder Lab and identify all ten unknowns correctly in two long class periods.  The others should be able to finish Thursday.  The two kids who have finished will do an extra lab and film it Thursday.  I am having the kids identify all ten before checking their answers.  I circle the incorrect unknowns.  They retest and correct.  It takes two or three corrections.  Usually, the kids mix up baking soda and baking powder.  Tell them to narrow down glucose and sucrose; then the kids can do the Benedict's test.  The two voltage probes were producing inconsistent results.  I brought out conductivity probes instead.  Here are more pix.

This is the Benedict's or copper reduction test for glucose.  The colors change to green and a rusty red.

                                 I used these conductivity meters instead of voltage meters.