Today was a pretty awesome day!
We learned about solubility, the ability to dissolve. Solvents are what is doing the dissolving. For example, in salt water, water is dissolving the salt, so water would be the solvent. Solutes are what is getting dissolved. In the previous example, the salt would be the solute. Well today we observed some cool dissolving!
Our experimental question was this: What is the best packing material to mail limonene? We tested out water first on styrofoam and cornstarch packing peanuts, to see what water would do. We were surprised to find that the water actually dissolved the cornstarch... so that's why they are called biodegradable! We ate some just cuz! That was fun!
Then we tested out the limonene on the two types of packing peanuts. We observed that the limonene quickly dissolved the styrofoam, but didn't dissolved the cornstarch. So it effected the materials completely opposite from water.
We also observed the dissolving powers of acetone. Some of us even got to take home a cool acetone art display (styrofoam cup partially dissolved into this new cool shape.)
Now, we touched base on the chemistry going on here (super advanced for fifth graders, but guess what- we are smart and we could handle it!)
Some background info:
Limonene is found it citric fruits and is in many cleaning supplies. Acetone is found in nail polish removers and is used as paint thinner.
Solute/Solvent Lesson
Here's the chemistry of what's going on in today's lab:
Styrofoam is made of polystyrene foam. When you dissolve the Styrofoam with acetone or limonene, or organic solvents, you can see just how much air is in the object. A lot of what you are seeing in something made of styrofoam is actually just air. So when we pour a solvent on styrofoam, the air is released, making it look like we dissolved a huge amount of material into a tiny amount of liquid. We did dissolve the styrofoam, but it's not as much as it looks! Cool optical illusion!
Next up, to take it a huge step in the advanced direction, we need to understand polar and non-polar molecules.
This is complicated, but we are going to talk about it as simply as possible. A molecule is considered polar if it is asymmetrical in its geometry and its electronegativity. Here's an easy way of trying to figure out if something is polar or non-polar. "Polar molecules have an uneven distribution of electrons that cause one end of the molecule to have a positive charge and the other to have a negative charge...A quick way to get a gauge of whether the molecule is polar or not is to look at the diagram of the molecule. Is it symmetrical on all counts? This includes the types of atoms, the orientation of the atoms, and the number of bonds. If so, then the molecule is most likely non-polar. If not, the molecule will probably be polar because it is "uneven"."
Michael Ugulini described this saying, "A molecule is classified as a polar molecule when the arrangement of the atoms is such that one end of the molecule has a positive electrical charge and the other end has a negative charge. A polar molecule forms when an atom of high electronegativity bonds with a less electronegative atom. A polar molecule has electrical poles.
Water is a polar molecule. Ammonia, Sulfur Dioxide, and Hydrogen Sulfide are case in point of polar molecules of materials, which are gases under standard conditions.
Conversely, a non-polar molecule does not have electrical poles.The electrons are distributed more equally. Therefore, a non-polar molecule does not have a profusion of charges at the opposite ends. The majority of hydrocarbon liquids are non-polar molecules. An example of this is gasoline. Examples of non-polar molecule gases are Helium, Hydrogen, nitrogen, and methane among others. In addition,oil is a non-polar molecule.
Therefore,a molecule in which the bond dipoles present do not cancel each other out is a polar molecule. A non-polar molecule, in essence, is whenthe charges all cancel each other out.Non-polar molecules do not have charges at their ends.
Polar moelcules are a type of molecule that will dissolve in water. Non-polar molecules are a type of molecule that will not dissolve in water."
Advanced crash course video on polar and non-polar, but take a dive and see if you can absorb anything
But why does water only dissolve the cornstarch packing peanut and limonene only dissolves the styrofoam packing peanut? Polystyrene is a non-polar material, so it only dissolves in a non-polar solvent (like acetone, limonene.) Cornstartch is a polar material so it only dissolves in a polar solvent (like water). Polar dissolves polar. Polar solvents are all capable of forming hydrogen bonds with water to dissolve in water. Non-polar solvents can't form enough hydrogen bonding per molecule to dissolve in water, so water can't dissolve non-polar materials. But, non-polar dissolves non-polar (like acetone and styrofoam.)
Here's a list of polar and non-polar solvents.
Polar and NonPolar Solvents Why/Explained
Explaining polar/nonpolar
Polar: water, ethanol, acetone, gasoline, oil
Non-polar- gasoline, oil, acetone, limonene
Classification of solvents
We learned about solubility, the ability to dissolve. Solvents are what is doing the dissolving. For example, in salt water, water is dissolving the salt, so water would be the solvent. Solutes are what is getting dissolved. In the previous example, the salt would be the solute. Well today we observed some cool dissolving!
Our experimental question was this: What is the best packing material to mail limonene? We tested out water first on styrofoam and cornstarch packing peanuts, to see what water would do. We were surprised to find that the water actually dissolved the cornstarch... so that's why they are called biodegradable! We ate some just cuz! That was fun!
Then we tested out the limonene on the two types of packing peanuts. We observed that the limonene quickly dissolved the styrofoam, but didn't dissolved the cornstarch. So it effected the materials completely opposite from water.
We also observed the dissolving powers of acetone. Some of us even got to take home a cool acetone art display (styrofoam cup partially dissolved into this new cool shape.)
Now, we touched base on the chemistry going on here (super advanced for fifth graders, but guess what- we are smart and we could handle it!)
Some background info:
Limonene is found it citric fruits and is in many cleaning supplies. Acetone is found in nail polish removers and is used as paint thinner.
Solute/Solvent Lesson
Here's the chemistry of what's going on in today's lab:
Styrofoam is made of polystyrene foam. When you dissolve the Styrofoam with acetone or limonene, or organic solvents, you can see just how much air is in the object. A lot of what you are seeing in something made of styrofoam is actually just air. So when we pour a solvent on styrofoam, the air is released, making it look like we dissolved a huge amount of material into a tiny amount of liquid. We did dissolve the styrofoam, but it's not as much as it looks! Cool optical illusion!
Next up, to take it a huge step in the advanced direction, we need to understand polar and non-polar molecules.
This is complicated, but we are going to talk about it as simply as possible. A molecule is considered polar if it is asymmetrical in its geometry and its electronegativity. Here's an easy way of trying to figure out if something is polar or non-polar. "Polar molecules have an uneven distribution of electrons that cause one end of the molecule to have a positive charge and the other to have a negative charge...A quick way to get a gauge of whether the molecule is polar or not is to look at the diagram of the molecule. Is it symmetrical on all counts? This includes the types of atoms, the orientation of the atoms, and the number of bonds. If so, then the molecule is most likely non-polar. If not, the molecule will probably be polar because it is "uneven"."
Michael Ugulini described this saying, "A molecule is classified as a polar molecule when the arrangement of the atoms is such that one end of the molecule has a positive electrical charge and the other end has a negative charge. A polar molecule forms when an atom of high electronegativity bonds with a less electronegative atom. A polar molecule has electrical poles.
Water is a polar molecule. Ammonia, Sulfur Dioxide, and Hydrogen Sulfide are case in point of polar molecules of materials, which are gases under standard conditions.
Conversely, a non-polar molecule does not have electrical poles.The electrons are distributed more equally. Therefore, a non-polar molecule does not have a profusion of charges at the opposite ends. The majority of hydrocarbon liquids are non-polar molecules. An example of this is gasoline. Examples of non-polar molecule gases are Helium, Hydrogen, nitrogen, and methane among others. In addition,oil is a non-polar molecule.
Therefore,a molecule in which the bond dipoles present do not cancel each other out is a polar molecule. A non-polar molecule, in essence, is whenthe charges all cancel each other out.Non-polar molecules do not have charges at their ends.
Polar moelcules are a type of molecule that will dissolve in water. Non-polar molecules are a type of molecule that will not dissolve in water."
Advanced crash course video on polar and non-polar, but take a dive and see if you can absorb anything
But why does water only dissolve the cornstarch packing peanut and limonene only dissolves the styrofoam packing peanut? Polystyrene is a non-polar material, so it only dissolves in a non-polar solvent (like acetone, limonene.) Cornstartch is a polar material so it only dissolves in a polar solvent (like water). Polar dissolves polar. Polar solvents are all capable of forming hydrogen bonds with water to dissolve in water. Non-polar solvents can't form enough hydrogen bonding per molecule to dissolve in water, so water can't dissolve non-polar materials. But, non-polar dissolves non-polar (like acetone and styrofoam.)
Here's a list of polar and non-polar solvents.
Polar and NonPolar Solvents Why/Explained
Explaining polar/nonpolar
Polar: water, ethanol, acetone, gasoline, oil
Non-polar- gasoline, oil, acetone, limonene
Classification of solvents