Crystal Hydrates and Occluded Liquid: Structural Solvent and Surface Wetness Are Different States

Define the Phase or Process Boundary

IUPAC's crystalline-hydrate definition places water molecules within the crystal structure. Water detected in a recovered solid sample can also include separate retained liquid. A total water result alone does not locate that water.

Review a Hypothetical Comparison

Suppose an invented sample contains 4 mg total water. A hypothetical, independently supported compartment interpretation assigns 3 mg to the crystal structure and 1 mg to separate retained liquid. Removing only that separate 1 mg would leave 3 mg water; it would not prove inadequate dewatering. Conversely, assuming all 4 mg is lattice water could conceal retained mother liquor. The compartment assignment needs real structural/state evidence, not just subtraction from the total-water test.

Keep the Evidence with the Decision

Keep total-water measurement, structural-form identification and retained-liquid evidence separate. Record whether the treatment could change the solid form, because a changed form would alter the inventory interpretation. Use the balance to identify missing evidence rather than prescribing a drying temperature from the hydrate label.

The compartment masses are fictional. This guide gives no dehydration procedure or stability limit and does not calculate a weighed hydrate's analyte equivalence.

Which evidence identifies lattice-associated solvent rather than liquid held with a crystal product?

This blank worksheet is for your own project. It contains no H M machine trial result.

Customer Questions

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

• IUPAC's crystalline-hydrate definition
• Reference from hmpharmamachines.com