What is the hardness (concentration of Ca2+ ions) in various types of water?

Kenneth Lin, Gaius Ong, Jonathan Tai, Michael Fifield

ISB Tap Water

Trial # Initial Volume(±0.1 mL) Final Volume (±0.1 mL) Difference(±0.2 mL)Trial 1 1.8 43.2 41.4Trial 2 2.7 45.7 43.0Trial 3 3.0 41.8 38.8

Distilled, De-Ionized Water from Wash Bottles

Trial # Initial Volume(±0.1 mL) Final Volume (±0.1 mL) Difference(±0.2 mL)Trial 1 0.0 0.0 0.0Trial 2 0.0 0.0 0.0Trial 3 0.0 0.0 0.0

Yosemite Tap Water

Trial # Initial Volume(±0.2 mL) Final Volume (±0.2 mL) Difference(±0.4 mL)Trial 1 9.0 78.2 69.2Trial 2 5.8 66.2 60.4Trial 3 6.0 68.2 62.2

Drinking Fountain Water

Trial # Initial Volume(±0.1 mL) Final Volume (±0.1 mL) Difference(±0.2 mL)Trial 1 1.8 19.9 18.1Trial 2 19.9 29.6 9.7Trial 3 5.2 16.5 11.3Trial 4 0.8 19.5 18.7

Mineral Water

Trial # Initial Volume(±0.1 mL) Final Volume (±0.1 mL) Difference(±0.2 mL)Trial 1 0.0 0.0 0.0Trial 2 0.0 0.0 0.0Trial 3 0.0 0.0 0.0

Water Drum (Watson's distilled/de-ionized H2O)

Trial # Initial Volume(±0.1 mL) Final Volume (±0.1 mL) Difference(±0.2 mL)Trial 1 0.0 0.0 0.0Trial 2 0.0 0.0 0.0Trial 3 0.0 0.0 0.0

Conclusion and Evaluation