Ap Chemistry Penny Lab

In performing these sets of experiments, in which we would drop a water/water solution onto the surface of a penny, we were trying to test and experiment the bonding qualities of water when made into a solution compared to when the water is pure. When we dropped pure tap water on to a penny, the water, instead of flowing and spreading out, stayed together in a single drop on the penny. We wanted to see how different substances affected this phenomenon. When we formulated our guiding question we made sure to preserve these intents in the language: how do foreign substances influence the bonding quality and strength (to the top of a zinc penny in specific) of water? Since these experiments were conducted in groups, we set up a few roles to

Our hypothesis was partially correct, the property changing substances did have the weakest coherency with the lowest drop counts of 23(carbonated), and 14(soap), and pure water did have the strongest bond. What we also found was the the salt also dampened the liquid’s ability to hold onto a penny in large volumes, as all the different salts had a drop average of 24(28x2 & 16), five less than Tap water’s drop count (30). This led us to conclude that pure water has the strongest bond and that all foreign materials weaken the coherency of water. This evidence has led me to believe that similar substances are attracted and are more coherent towards themselves, in this case the water pieces get separated and generally less connected on a really small level due to the obstruction of foreign objects, this is why the different salts perform better than the huge air bubbles or the slippery properties of soap since the latter is more obstructive and the former dissolves with the water and blocks less. When studying a few other groups’ conclusions and data we did indeed find differences: some groups had differing data where a solution had better coherence than water itself which led to differing conclusions. This could be due to differences or error in experiment procedure. Personally I think our group were extremely careful with the experiment and have made a worthy theory of the coherent properties of differing