Are there ANY experiments possible using the silica in the dehumidifiers found in food packages?

use it for dessicating purposes

Are there ANY experiments possible using the silica in the dehumidifiers found in food packages?

For all intents and purposes, it's inert.

dissolve in HF if you are crazy.

coat them in NI3 and leave them lying around the place

im telling you man. it's a great dessicant. otherwise it's useless. but use it to dry things; really, it's good for such purposes and dessicating is very important in purification of products

Silica makes for an awesome solid support for postassion permangenate and dichromate in the solid-state oxidation of alcohols to aldehydes without over oxidation of the aldehyde to the carboxylic acid.

You can take silica and mix it with finely ground magnesium powder and then heat the mixture in a test-tube. This will be a mild thermite of sorts and the Mg will pull the O2 off of the SiO2. Take the reaction products and dump them into some HCl. Any excess Mg will dissolve, any magnesium silicide will form silane which will immediately react, and all that you'll be left with is elemental silicon.