22 February 2013
Pink and Bubbly
Phenolphthalein is an acid/base indicator which expresses the properties of an element. It is colorless when it is an acid and pink when it is a base. Ammonium is familiar base, used for cleaning oils and grease from any types of surfaces. Ammonium is a fairly strong base with a pH of 11 and will dissociate completely into an aqueous solution (water). Water is universal and has a neutral base with a pH of 7. A Danish chemist named Johannes Bronsted and an English chemist by the name of Thomas Lowry suggested and then defined two theories. The bronsted-lowry theory defines an acid as a hydrogen-ion donor, which basically means the element would donate an ion. Unlike a bas is a hydrogen-ion acceptor which takes on an ion. I learned ammonium is very soluble in water and accepts a hydrogen ion, so it would be a bronsted-Lowry base whereas water is a hydrogen-ion donor, or a bronsted-Lowry acid. Hydrogen ions would transfer to the ammonium in a reaction to form a conjugate acid. A conjugate acid is formed when a base gains a hydrogen ion. Hypothesis: Oxygen from our breath changes the solution.
1) Determine how an acid is neutralized
2) Determine why a color change occurred
3) Learn the difference between an acid and base.
4) Does the timing and color change have a pattern?
5) Does blowing into the indicator solution change its pH? Materials
1) Safety Goggles 2) Timer 3) Phenolphthalein 4) Pipette 5) Erlenmeyer flask 6) Straw 7) Apron 8) Ammonia NH3 3drops 9) Water 30mls Observations:
The student began with 30mls of water, 3 drops of NH3 (ammonium), and 6drops of Phenolphthalein. The student then...