We recently had a lab to show what we had learned on ionic and covalent compounds. When atoms come together they will either form ionic or covalent bonds. This depends on whether or not there is a difference and exchange of electrons. Ionic bonds are formed when an element gives its electrons to another forming a bond, on the other hand a covalent bond will be when two of the same element come together to share the same electrons. When an object is ionic it is polar, meaning that there is a difference of charge. Polar substances have a tendency to dissolve in polar solvents, where as non-polar substances (i.e. covalent bonds) will dissolve in non-polar solvents. This is an objects solubility, the level at which a substance dissolves in a solvent. Water is a great solvent, it's semi-covalent, yet is still polar. Non-polar substances tend to be hydrophobic as they don't dissolve in water, vise versa polar things tend to hydrophilic and dissolve in water. What we wanted to test is if we could make sand, a normally hydrophiliac material, hydrophobic. Normally, when you apply water to sand the sand becomes very wet and dense, but by giving it a silicone exterior we would effectively protect the sand from getting wet and it'll become hydrophobic. For the actual experiment we sprayed our sand (which was colored pink and green for our convenience) around six times, stirring it between every coat, then allowing it to dry.(the orange color is not from the spray, that's just what it looks like after mixing the pink and green colors of the sand.) After the preparation was complete, we played around with how it reacted with water. We saw how for the most part it did not mix with the water, it just remained at the bottom in clusters, when pulled out it acted like regular dry sand. Our results for the experiment were almost exactly as we expected. we ended up with sand that for the most part did not get wet and was dry when we took it out. There was some margin of error of course seeing as some did clump a bit and separated like normal wet sand. I wasn't the one who did the stirring/spraying for this lab so I cannot say I contributed nor, subtracted from the final results of the experiment. Because this was a class experiment I worked with the others at my table to do this experiment. They were Matthew, David, Isaiah, and Micah. We never actually did too much together besides test the sand, but as group mates they are very fun to work with and can be focused when need be. Although if we were to do this again, I would've mixed the sprayed sand around more to really make sure it was coated, I wouldn't want there to be even more loose wet sand. I feel as if I will be working with this group and it's members many more times because of our relations and ease of ability to get things done. But not for this experiment. This could easily be extended by testing out different liquids it can go in and seeing how it reacts, though I wouldn't want to. But as for what happened in our experiment, I hope my explanation for what happened is satisfactory. I believe that on a molecular level, the silicone spray bonded with the sand covalently to create to create a water proof membrane to the sand. This mostly seems to happen only when silicone is applied to silica based structures, such as sand. Some things that I took from this experiment was that we must take care to do all we can to improve the desirability of our results. I got this from us not having mixed the sand well enough to make it completely waterproof. This can be applied to everything, from future experiments, to just workmanship. |
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AuthorHello there! I am a sophomore here at High Tech High, and on this blog I will be making weekly posts to what I've been doing in my 10th grade chemistry class! So check back often! Archives
May 2015
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