Before we did this lab, we had to go over some concepts first fro us to understand what is going on during the lab. One concept was ionic compounds and convalent compounds. In ionic compounds, the atoms are bound together by oppositely charged ions. An ionic compound makes a very strong bond and they are formed with both metal and non metal elements. All ionic compounds are polar so that means that one side of the compound is more positive and the other side is more negative than the other. For example, sodium and chlorine form an ionic bond to make NaCl which is table salt. In covalent compounds, the atoms share electrons. Covalent compounds are formed with non metals with non metals and they usually have weak bonds. Since the electrons are shared equally among the atoms, there is a balence in electrons making the compound be non polar. Another concept is polarity and we learned that most atoms have poles like how the earth has a north pole and a south pole. One side of the atom would be positive and one side of the atom would be negative. An example of this is water, and the molecules for water is H2O meaning that there is two hydrogen atoms and one oxygen atom. Like we learned before, some atoms want to gain electrons and some want to lose some and depending if the atom wants to gain or lose, it either has a negative charge or a positive charge. In H2O the hydrogen gives electrons giving it a positive charge and oxygen gains electrons, giving a negative charge. So in the end H2O is magnetic. Solubility is the ability for water to dissolve things. Water can dissolve anything that is hydrophilic or ionic. The definition of hydrophilic is that it can dissolve in water. Examples of hydrophilic objects are salt and other ionic things like ammonia and bleach. The opposite of hydrophilic is hydrophobic and that is when the objects can't dissolve in water. Examples of hydrophobic objects are covalent things like oil. Oil can't dissolve in water because it isn't polar so it is immiscible. A key to remembering this is "LIKE DISSOLVES LIKE" so polar objects dissolve in polar objects, nonpolar objects dissolve in nonpolar objects, etc.
Regular sand is hydrophilic so the water can make the sand wet. Most sand we come to contact with is hydrophilic and that is what is what the earth naturally gives us. In the lab we are making magic sand. What makes magic sand so magical is that it can't get wet. The reason that it can't get wet is because we change the polar of the sand from being polar to being nonpolar because the reason that the sand can get wet is because it has the same polar as water. We made the sand non polar by spraying it with silicon spray because silicon spray is covalent and non polar. Coating the sand in silicon would eventually make the sand water proof. We had to coat the sand in silicon spray about five times and when we felt it was ready. We tried to get the sand wet with water. First we poured some water on the sand and it made the water form little bubbles that won't sink into the water. Then, we tried it the other way around where we put the sand in the water. When we put the sand in the water, it mostly stayed at the top and made a layer of sand up there, then we tried to push it down with our fingers and when we did that the sand formed like a protective layer around my finger and when I took my finger out, it wasn't wet at all. After that, we pushed that sand down so it would sink and it did and it clumped up in to something that looked like a air bubble. Reflection: I think the results was really good and what contributed to that was that Andrew did the lab with the other class and it didn't really work well with them. So from the previous lab he learned that he probably didn't coat the sand as well so he did more coats on our sand. And since ours had more coats, the sand didn't get wet until we separated the sand. I think I performed pretty well, I listened to the instructions and performed the instructions well for the lab to work. For this lab I worked with Carmina, Morgan, Maia and Erika. I think we worked pretty good as a team and had great ideas when it came to laying with the sand. It was Morgan's idea to put the sand in the water instead of the other way around and I think that was the best part of playing with the sand. I wouldn't really do anything different to change the results because I think this lab was done well. I also wouldn't mind working with this group again because we seem to work well together and we got a great result in the end. From this lab, I took away that you aren't always gonna get what you wanted on the first try and also why and how things are waterproof. Also I learned about ionic and covalent bonds and I think I understood the concept pretty well with the lab. |
AuthorMy name is Ivy and this is my tenth grade chemistry blog. Archives
November 2015
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