1. Home
  2. hydrates

hydrates

Hydrate Labs, Microscale Chemistry and Cage Fighting....

Chad Husting | Tue, 11/01/2016 - 19:56

For years my students would heat the hydrates in glassware, burn themselves, break the glassware and splatter salts and thus their data, all over the lab bench. A few years ago Bob Worley came up with a great microscale technique. Essentially, it takes a used bottle cap without the plastic and this is used as the dish. Next, there is about a three inch machine screw that goes through a drilled hole in the cap. A nut is placed on the screw to hold everything in place and cheap pliers are used to hold the entire assembly over the flame.

Cookbook to Inquiry....Another Attempt

Chad Husting | Sun, 10/25/2015 - 19:32

There is a hydrate lab which is done by many teachers. Typically, students first use a known hydrate and are provided the formula.  As an example, they might use CuSO4 . 5H2O.  On paper, they would work through the percent by mass of water in copper (II) sulfate pentahydrate.  They then would be given a mass of the copper (II) sulfate pentahydrate, calculate how much water they should lose and then they would heat it and compare the data with the calculated value. Next, they are given an unknown hydrate.  They are also given the molar mass of the unknown salt of the hydrate and they have to calculate the molar ratio of salt to water based on their data.  Here is one possible way to “tweak” this lab.