![]() The bulb is gently squeezed to prepare room for a small amount of solution to be drawn in. The ammonia-filled pipet is inserted into a clear cup with water (or a slightly acid) solution with an added acid/base indicator. The top pipet is removed once the gas has been collected. The top larger pipet bulb collects the ammonia gas. The pipet apparatus (right) is placed in a hot water bath to increase the rate of the production of ammonia gas. Simply insert the jumbo pipet over the thin-stem of another pipet, which is partially filled with concentrated ammonia solution. The Duke Department of Service Learning funded Ken to attend the ChemEd 2015 conference and participate in the Generations Symposium.Ĭlip off the stem of a jumbo pipet, leaving about 1 cm of the stem. When the solution is drawn into the pipet, the color is purple indicating pH around 10.įunding for the Duke Chemistry Outreach program provided by the Powell Family Trust, the Duke-Durham Neighborhood Partnership and Bio-gen Idec – Research Triangle Park. The ammonia gas-filled pipet is placed in water with universal indictor - the color green indicates a pH around 7. These issues along with safety concerns limit the Ammonium Fountain to a front-of-the-class, teacher-presented demonstration.įig 2. ![]() ![]() As well, it often includes materials (multiple flasks, luminol and anhydrous ammonia) that can potentially distract viewers from the desired learning outcomes. Repeating the demo for different indicators is often not feasible. The Ammonia Fountain, as described in many demonstration texts and online, is typically performed on a large scale and requires a great deal of setup. ![]() For both reactions, heating the system favors the reverse direction. A small amount of the dissolved ammonia reacts with water to form ammonium hydroxide, which dissociates into ammonium and hydroxide ions. The dissolving of ammonia in water forms a basic solution. The relatively high solubility is attributed to the hydrogen bonding that takes place between the ammonia and water molecules. This is an easy, colorful and safe microscale version of the Ammonia Fountain.Īmmonia gas is very soluble in water. Penney Sconzo presented this nifty demonstration at the ChemEd 2015 Generations Symposium in Kennesaw State University, Kennesaw GA. ![]()
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