Water in a Hydrate

1
Water in a Hydrate

• Each lab group will receive a container
  containing a hydrate. The hydrate has the general
  formula
• SALT . X H2O
• The molecular mass of the anhydrous salt will
  be given. Determine the value of X in the
  formula of the hydrate.

2
Water in a Hydrate

• Previous labs included determining the percentage
  of water in a hydrate and determination of an
  empirical formula.
• This exercise requires use of the hydrate labs
  procedure and the empirical formula labs
  calculations.

3
Water in a Hydrate

• Data
• Mass hydrate 3.00 g
• Mass water 1.12 g
• Molecular mass anhydrous salt 159.5

4
Water in a Hydrate

• Calculation
• 3.00 g hydrate 1.08 g water 1.92 g salt
• 1.92 g x 1 mol/159.5 g 0.0120 mol salt
• 1.12 g water x 1mol/18 g 0.0622 mol H2O
• 0.0120 mol/0.0120 mol 1 mol salt
• 0.0622 mol/.0120 mol 5.18 mol water

SALT . 5 H2O