CuSO4 * 5H2O

Formula for a Hydrate

Chan Chan Cheng

Date published: Nov. 10th

Lab partner: Emi Ushida

Purpose / Goal

To determine the formula of the hydrate and to find the percentage of water in a hydrated copper sulfate.

Materials

Apparatus

Porcelain crucible

Clay triangle

Safety goggles

Lab apron

Ring Stand

Iron Ring

Laboratory Burner

Scale

Tongs

Procedure

1. Take a crystal hydrate.
2. Get mass of hydrate by measuring.
3. Get mass of dehydrated crystal.
4. Determine the formula of the hydrate.

Data / Observation

 Target Mass in grams Crucible 13.55g Crucible with hydrate 15.84g hydrate 2.29g Crucible and dehydrated copper sulfate 14.99g Dehydrated copper sulfate 1.44g Water 0.047g

Before we heated copper sulfate, it was blue. Then it turned to white when it was dehydrated.

Calculation

CuSO4          63.55g + 32g + 4*16g = 159.45g

1.44g CuSO4 ( 1 mole CuSO4 / 159.45g CuSO4 ) = 0.009 moles of CuSO4

0.009 moles of CuSO4 ( 6.022*1023 / 1 mole) = 5.42*1021 molecules of CuSO4

H2O          2*1.008g + 16 = 18g

0.85g H2O ( 1 mole H2O / 18g H2O ) = 0.047 moles of H2O

0.047 moles of H2O ( 6.022*1023 molecules of H2O / 1 mole H2O )                                                           = 2.83*1022 molecules H2O

5.42*1021 / 2.83*1022 = 5 (approximately)

Conclusion

Therefore the formula is CuSO4 * 5H2O. There are five water molecules per one copper sulfate.