Purpose: The purpose of this lab is to analyze the percent water in a crystalline hydrate to identify the hydrate from a list of possible unknowns.

Hypothesis:If we can calculate the percentage water loss, then the identity of the hydrate can be determined because each hydrate has a specific composition.

Variables:

IV:The type of hydrate

DV:The Percentage water lost

Control:The accepted percentage of water lost

Materials/Safety: hot plate, evaporating dish, watch glass, sample cup, gloves, wire gauze, electronic balance

Summary of Procedure: The solid hydrate will be heated to remove the water, and the percent water will be determined by measuring the mass of the solid before and after heating.  The hydrate will be identified by comparing the percent water in the hydrate with the percent water calculated for a series of possible unknowns.