CHEMLAB: Quiz 2 Experiment 2

https://www.youtube.com/watch?v=EXVlaIxjTvc

hydrate

(mostly) ionic compounds that trap water molecules in their structures as they crystallize

• do NOT appear to be wet

anhydride

a compound derived from another compound by the removal of water

anhydrous

the condition of a compound that has had all water molecules removed

non-hydrate

A substance that does not include water in its molecular structure.

This term generally refers to compounds that lack water molecules either in their crystal structure or as part of their composition.

hygroscopic

of a substance) tending to absorb moisture from the air.

Hygroscopic materials attract and hold water molecules from the surrounding environment, which can often lead to changes in physical state (e.g., from powder to liquid).

thermal decomposition

chemical reaction where a compound breaks down into simpler substances when heated.

residue

substance that remains after a chemical reaction or process, such as thermal decomposition

How do you drive off the water in a hydrate?

heating

To find mass water lost,

hydrate mass - residue mass = mass of water lost

molar mass of water

18.01528 g/mol

Moles of anhydrous compound =

Mass of residue / molar mass of the anhydrous compound

Calculate the mass of water contained in x moles of y hydrate

if asking for moles,

mass / molar mass