Friday's Chemistry Lab

8/31/2012

Type or paste your responses to the following questions in the comments for this post by class on Tuesday Sept. 4th.

For Part I:

1. Do you believe "Oobleck" is a solid or a liquid?
- Use your observations.
- What information did you gather from your experience with it that led to
your decision?

2. Propose an explanation to the mechanics behind Oobleck's behavior. Try to use insight from your understanding of molecules in solids and liquids.

For Part II.

1. What did you notice when you placed a piece of dry ice into water?
2. What simple ratio did you find?
3. What does that simple ratio tell you about the difference in distances between molecules in solids and gases?

You only need to supply a paragraph or two for each Part to address these questions. It does not have to be a huge report - just try to make it clear and concise.

If you need to look at the activity again, it is available in the links section here:

Lab 1

39 Comments

Bryanna Rivera link

8/31/2012 11:04:11 am

Chem Lab 1
Do I Believe "Oobleck" is a solid or a liquid?
I think that "Oobleck" is a solid that acts like a liquid.
When "Oobleck" was on the shaker table, it behaved more like a solid, like when we were pushing it to the center to form a pillar. When it was left alone, it behaved like a liquid.
Proposed explanation:
Maybe when oobleck is being moved, the molecules/atoms are forced to be solidly packed, and when it is left alone, the molecules/atoms are no longer in an orderly fashion therefore behaving like a liquid.

What did I notice when I put the dry ice in water?
Bubbles were shooting from the ice to the surface
A ghostly vapor occurred (like when it wasn't in water, but more aggravated)

Simple ratio we found was 1:1000
That means that the molecules are 1000 times more spread apart as a gas inside the balloon versus as a solid.

Jordan Destacamento

8/31/2012 11:57:37 am

I believe Oobleck is a solid, but it acts like a liquid. it seems hard at first when you tap it quickly. But when you leave your hand on it, it seems to melt in a way and become a liquid. I think the mechanics behind this is that the water isn't thick enough to make it a solid, so it kind of does a little bit of both.

I notices that when I put the dry ice into water, it would bubble up at the bottom and then it would smoke up as it rises to the top.
We had a hard time finding out our ratio because we were confused.

miles herrera

8/31/2012 02:19:02 pm

i believe oobleck is a liquid, because by the feeling and movement, it acts more like a liquid than a solid. Then it depends on the ratio of water you put in.the more water you put in the more molecules are moving.

when we put the dry ice in the water it created a lot more vapor/smoke then when it was out of the water, i think the simple ration is 1-100, because 1 part of the ice which in this case is the gas and the liquid which is the water is low. you only needed a little to produce enough compared to the balloon

Francisco M.

8/31/2012 04:19:15 pm

1-1
I think "Oobleck is both a solid and liquid but not at the same time. When it is left alone it acts like a liquid. When you move it or put force on it, it acts as a solid. The same thing happens with water when you hit it really hard. When I gathered a handful from the table and held it in my hand, it started to drip. I remembered about hearing that water can be as hard as concrete if hit hard enough. So while it was slowly slipping out of my hand I started moving my hand so that it turned harder and fall slower.

1-2
I think that when left alone some molecules go to the bottom (caused by gravity) and some stay above and when force is put on it the molecules switch or maybe they get mixed.

2-1
When I put a piece of dry ice into the water it made bubbles and it released smoke which is carbon dioxide. The smoke kept coming out of the container consistently for a while. Then it ran out of carbon dioxide to release.

2-2
1:5.36

2-3
If the ratio is 1:200 and there are two solid molecules and if they get turned into gas the distance will be 200 times the normal distance.

Sergio Ramirez

9/1/2012 02:35:10 am

I think the Oobleck is a liquid. Most of the things it does or you do with it has very liquidy features, for example like taking the shape of its container. Oobleck is only a solid when its under pressure or pressure is added to it. But if you were to give an explanation of it without touching or by simply just observing you would say it was a liquid. I think your able to control the molecules inside the oobleck, because when its in your hand and you just let it sit, the oobleck acts like a liquid because the molecules slide past each other and it just melts in your hand. But once you juggle it and keep adding pressure to various sides your basically telling the molecules to stay in there place and not to loose that shape their in.

When water was added to the dry ice in the container it started producing a kinda gas material that rose all the way to the top. I don't think my group found the ratio cause we didn't measure it, but i would guess that when the ice was a solid it was about 5cm long and once it was in the ballon fully spread it was about 10-40 times bigger. I think this tells me that gases take up way more space with a small amount of molecules. While a solid has way more molecules but they're all compressed in a small usually hard figure.

Ana Ramirez-Blanco

9/1/2012 05:20:04 am

I think Oobleck is a liquid because it takes the shape of the container it is put in. When my group poured the mixture onto the table it flattened out the way water would. I think the reason Oobleck acts the way it does and shares some of the characteristics as a solid, is that it does not retain heat very well, and therefor just uses the heat it comes in contact with. When you'd play with the mixture on your hands it would become super liquid-y and drip all over the place. I think that was because as the Oobleck stayed on your hand longer your body heat would transfer into it and therefor it had more energy and the molecules would move faster, like in a normal liquid such as water. However , when we just left it on the table and we'd just barely tap it, it seemed hard. This was because the longer the Oobleck was left alone, the more heat it lost, and the less energy the atoms had to use so they'd slow down and compress more like a solid.

When we put the dry ice in water it began to bubble much like it was boiling. While that was going on, what seemed like fog would rise out of the top of the glass. The piece of ice we put in to the balloon was about a cm wide and then balloon it inflated was 15 cms wide. When I put that information in to the formula for volume I got 0.523 for the ice and 1767.14 for the balloon. This means the volume was roughly 3000 times bigger. If this is right, then it shows how much more space is between each atom in a gas than in a solid.

Michael Gracia

9/1/2012 06:51:22 am

I believe Oobleck is what I decided to call a sliquid because it acts as both, more so a liquid then a solid. When I pounded it with my fist, it did leave a trace, a small amount of the Oobleck was on my fist, but when I put my hand down on it, my hand begun to sink into it, and it made it rather hard to take out. I believe the reason it does this is because when the cornstarch and water are mixed properly, the cornstarch is more dense then that of water, so the cornstarch sunk under, so it reacted when you put your hand on it like quicksand. When I put some on my hand, it solidified after awhile, and then began to break off, like baking soda and water does on a bug bite (it's a good remedy). At a molecular level, the cornstarch stays solid at the bottom, and the water stays liquefied. When on let's say, my hand, it all solidified after awhile.
When the dry ice was in the water, the effect was almost immediate, as gas streamed from the top, however after awhile, the gas went down after the water got cold. We measured a 1.5cm piece of ice, and put it into the balloon and the balloon went to 7cm total (1.5:7). I can't be sure if the ,measure was accurate, however, I guessed it'd be about 200 times bigger, and I'd prefer to stay close to my estimate. If correct, then there is 200x more space in between that of a gas then a solid.

Paisley Dutcher

9/2/2012 05:18:32 am

Lab 1 (part 1)

I believe that Oobleck is always somewhere in between a liquid and a solid. When we were observing it and interacting with it it was never only a liquid or only a solid, there were always pieces of both mixed in. Also when we applied pressure it didn't turn completely solid, it would simply turn into a thicker goo like substance, it only really turned solid when we applied lots of pressure and even then some of it would still be liquid.

Lab 1 (part 2)

From what I experienced with the Oobleck and what I know about molecules I think that Oobleck is a mix of a solid and a liquid that react differently from each other but at the same time. For example when you squeeze Oobleck in your fist most of it becomes solid but some still leaks between your fingers. I think this happens because when you squeeze all the little solids come together and stay in your hand and the liquid (because it slides around more easily) slips through your fingers but when you let go there is still enough liquid in your hand to mix back into the Oobleck and (because you're not pushing the solids together anymore) the liquid mixes in more evenly and it all becomes a liquid again.

Lab 2

1. When we placed a piece of dry ice in water we saw a reaction immediately. Bubbles of carbon dioxide streamed up from the dry ice and water vapor poured out of the container like smoke. After some time the water vapor went away with the bubbles and we were left with a glass of very cold water.

2. Our simple ratio was 1:1,000 (rounded to the nearest whole number)

3. This simple ratio tells us that when a solid (like dry ice) becomes a gas the molecules are about 1,000 time farther away from each other than they were when they were a solid.

matt larson

9/2/2012 06:08:58 am

In my own opinion I believe that the oobleck is more liquid then solid because when you add water to it and put on a table its natural stage looks to be liquid because you can see the oobleck moving around which is all the molecules scattering around I believe. In order to make the oobleck into a solid you have to collect the oobleck and keep moving it which makes it a solid. What I experienced with the obbleck once we put it in water was the differnt reactions it makes if you touch it quickly as to touching it slowly. If you were to touch it quickly it would act like a solid and your hand would come back up. If you were to put your hand on top of it and leave it there, your hand would start to sink into the oobleck. another thing our table did when we experimented with the oobleck was when we gather up oobleck in our hands it would feel like a solid because at the time it was but after we stopped moving it around in our hands, it slowly leaked out of our hands.
Now when I got the dry ice I hurt myself about a minute into experimenting with it by holding it too long in my hands. What our table found out about dry ice was when you put medal to it the medal vibrates and it makes an annoying screeching noise. also when you put a piece of dry ice on a table or any flat surface and the bottom of the dry ice is uneven the dry ice would make a loud noise and move around because its melting down the bottom to make it flat. are ratio was 1:100 and what that means is all the molecules inside the dry ice when the dry ice was a solid are nearly 100 times farther apart as to when you put them into water and it becomes a gas.

Jaden Jimenez

9/2/2012 07:55:44 am

Lab 1-Oobleck

1.) I believe Oobleck can be a solid or liquid depending on the situation it's in. To make it a solid you have to compress it and then it becomes a solid and keeps it shape but the moment you leave it alone it becomes a liquid and begins to thin out like a liquid in your hand or the table. Oobleck contains water within it which gives it the liquid state that it can be in, along with water it also contains corn starch(I think) that is a solid but also can be pat down from its powdery form to a compress solid form. So when these come together you get a solid/liquid substance.
2.)Well a solid is a substance where the molecules are close together so they aren't able to slide or move which makes it so you can't pass through the molecules making it solid, A liquid's molecules aren't so close so they can move and slide. In the Oobleck the molecules were able to slide and be free but when you compress it the molecules move closer together and thus making a solid substance. When you release the pressure the molecules move again and then become a liquid.

Lab 2-Dry Ice

1.)When we placed the dry ice in the water the frozen carbon dioxide began to melt because the water is warmer than the ice, as it melts the carbon dioxide the gas began to pour over the edge of the container and go onto the table and then disappear.
2.)The simple ratio we found was 1:2,000
3.) The simple ration tells us that when the dry ice is placed in a container and becomes a gas the molecules within the gas are x2,000 as far away from each other then when it was a solid.

Alyssa Abeyta

9/2/2012 09:59:59 am

PART ONE
1. Do you believe "Oobleck" is a solid or a liquid?
I think Oobleck is like gum. Its hard but when messed with it, it softens. Or it softens/ gooes up when next to warmth (such as in our hands or touching our fingers).

2. I think if i had the option i would say it is between a solid and liquid, but since i have to choose one. I choose solid. But like i said earlier it becomes a liquid when it is next to wamth.

PART 2
1. When the dry ice was placed into the water, the water separated the molecules (i think) and let bubbles out slowly. It also started "smoking" out of the beeker.
2. .4=.08
3. The molecules in the ice were 1,000 times spread apart than it started when it was placed in water.

Mason Thurman

9/2/2012 02:35:24 pm

Lab 1
I think that oobleck is a liquid but when it comes in contact with energy it becomes a solid because the energy makes the molecules compress and gives the feel of a solid.

Lab 2
I observed the dry ice making water vapor in the air visible and when you place dry ice in water it makes a lot of mist like substance in the air. I think it did this because when the dry ice was alone it made a small amount of cold air around it but since there was more water to turn into water vapor it made a lot more. I found it was around 1:200 so it was 200 times the size when it turned into a gas. It tells us that a solid is the same size as it is when it starts and gradually expands to take up a much larger area.

Marco Day

9/2/2012 03:17:54 pm

Q1. Do you believe "Oobleck" is a solid or a liquid?

I believe "Oobleck" is a liquid, because just like a liquid, it can be poured. Even though the "oobleck" becomes a solid when compressed, it will return back to a liquid if left undisturbed. Which tells me the molecular in "oobleck" are tight enough to be held under pressure, but not under regular conditions

Q2: Dry ice

When dry ice is placed in water, it freezes the water instantly leaving a haze. I didn't measure the balloon, only had one balloon and completely forgotten about it.The dry ice I measure was 2 cm long an I'm guessing the balloon inflated twice as big. Which tells me gasses take more space then solids, because the molecular in gas are less packed then solids.

Kelley Hernandez

9/2/2012 04:26:02 pm

Oobleck can behave like a solid and ooze like a liquid. I believe It's a liquid because it flows and takes the shape of whatever is holding it. I think oobleck acts the way it does because the grains of starch absorb the water. When you put pressure on oobleck, the water is forced out of the starch and the starch molecules press against each other, causing it to behave like a solid.

The first thing I noticed when I placed a piece of dry ice into water was how the dry ice bubbled and produced a white fog over the surface of the water. The piece of dry ice we inserted into the balloon was about 1 cm wide. The simple ratio was 1:3,000. The ratio told us that the molecules were roughly 3,000 times more spread apart than they were when they were a solid.

Madison Clark

9/3/2012 05:24:43 am

For Part I:
1) I believe that the Oobleck is a liquid when its stimulated by an outside source. ie our hands touching it, it instantly "melted" as if it was water. when it was in its natural state it hardend making it a solid again.
2) in this case the starch acted like a sponge soaking up the water making it a solid. once we applied pressure to the Oobleck, the water was squeezed out of the starch making the mixture more watery, thus making it a liquid.

For Part II.
1) when we added dry ice to the water the ice made the water bubble and smoke emitted from the cup. the water was breaking down the ice's chemical compound creating a minor reaction, which explained the smoke.
2) my group broke a chunk off of our ice that measured to the size of 1 cm. when we put it into the balloon, the ice's gas inflated the balloon to about 15 cm.
3. when i put that information into the formula for volume I got 0.523 for the ice and 1767.14 for the balloon. which means that the volume was 3000 times bigger. this shows how much space was in between each atom.

Britton

9/3/2012 05:41:38 am

Part I:
I think Oobleck is a liquid because a solid’s molecules tend to keep their shape no matter what. When Oobleck is confronted by a force, it keeps its shape, but at most other times it tends to stay easily moldable and ever changing. For example, when someone would hit the Oobleck, their hand would bounce off and the Oobleck would not absorb the impact. However, when the Oobleck is poured, it’s molecules start to move and it turns into more of a liquid. If Oobleck was truly a solid, it wouldn’t pour so easily.

Part II:
When placed in water, I noticed the dry ice would form a bubble around itself, showing that it is a condensed gas. It also made the water colder and start to vaporize. When we put a piece of dry ice that measured 2 cm in diameter in a balloon, the balloon started to expand until the piece of dry ice was completely gone. Once the dry ice turned into a gas, the balloon measured 10 cm, this means the ratio of solid carbon dioxide to gaseous carbon dioxide was 1:5. This ratio shows that when carbon dioxide is a gas, its molecules are 5 times farther apart than if that same amount of carbon dioxide was a solid.

Elijah Sanchez

9/3/2012 05:49:23 am

Do I believe "Oobleck" is a solid or a liquid?

I believe Oobleck is a liquid. The reason I have came to this conclusion is because when the "surface" is penetrated and Oobleck is displaced it immediately fills back in when whatever was causing the displacement is removed. Another observation happened completely by accident. I put a piece of dry ice inside the Oobleck to see what happened, evidently it was uneventful. Between 30-45 minutes later I returned to that same pile of Oobleck on its plate and lifted it. When I picked it up a clump of Oobleck around where the dry ice was had frozen to the table. Solids do not freeze.

Although there is a problem with the idea of Oobleck being a liquid, it moves way too slow. My proposal to explain this is that the molecules in Oobleck move slower than molecules in other liquids.

When the dry ice was placed in water the amount of carbon dioxide released by the dry ice increased greatly. The simple ratio I found was roughly 1:1000 meaning that when carbon dioxide is in its gas form the molecules are 1000 times further away from each other than when its a solid form.

Javier Vizcarra

9/3/2012 07:12:22 am

I believe that Oobleck is mainly a liquid but also a solid. The reason I think its mainly a liquid is because when you let it rest it acts like a liquid and when you leave your finger in it your finger sinks down. But it also acts like a solid only when you hit it really fast your finger or hand bounces back so it acts like a solid to.

What I noticed when we added a piece of dry ice in water bubbles would start rising and cause a lot of what seemed like fog over the water. I believe that the fog formed because the water was not that cold and when you added the ice it would start to form it and after a while there would be less and less fog because the water was starting to get really cold. We weren’t able to find the ratio we didn’t really understand how to do it.

Sam Rizzuto

9/3/2012 07:41:55 am

Part 1

I believe Oobleck cannot be solely classified as either solid or liquid because it contains properties of both. At first glance it appears to be a liquid, but when you touch it the substance feels like some sort of goo. When it was poured onto the table it spread slowly like spilled water, but after being poked insistently the surface only hardened and took on more of a solid form. Perhaps it is a solid that acts like a liquid.

The molecules behavior resembles more of a liquid than a solid. On its own Oobleck simply spreads, so the molecules must be farther apart. But when forced together the molecules compile like those of a solid, giving it actual shape.

Part II

After placing a piece of dry ice in a glass of water bubbles immediately started shooting towards the surface, changing into water vapor upon contact with air and turning the glass very cold.

The simple ratio our group found was 1:1000.

This means that the molecules in gases are 1000 times farther apart then solids.

Diana

9/3/2012 08:29:50 am

For Part I:
1. I do believe that Oobleck is a solid, but when another force acts upon it I'll turn into a liquid. The reason for is because when I picked up the Oobleck it turned into liquid and when I placed it down it turned back into a solid. I think the reason why the Oobleck does what does is because of the ingredients of the corn starch mixed in with the water.

For Part II.
1. When we put the dry ice into the water, the dry ice started to bubble at a rapid speed forming a steam/fog to come out of the glass thingy. I believe that the chemicals from the dry ice mixed with the water made the dry ice to bubble and create fog. I think the ratio would be 1:100, I'm not sure though because I got confused.

Joanna Cardona

9/3/2012 08:35:21 am

Do you believe "Oobleck" is a solid or a liquid?
I believe that Oobleck can be both a solid or a liquid due to the fact that it stays still, it did not move once we placed it on the table therefore it can be a solid, on other hands it can be a liquid because when we used would grab it,it would slide out of our hands. Once we mixed the water with the corn starch it was automatically becoming a solid,

1. What did you notice when you placed a piece of dry ice into water?
When we put a small piece of dry ice into the water was making noise and the gas from the dry ice was coming out and looked like steam,
2. What simple ratio did you find?
My group put about 1inch of dry ice into the balloon and we got 1.002796163

3. What does that simple ratio tell you about the difference in distances between molecules in solids and gases?
I was a little unclean on how to get the difference in distance between molecules in solid gases.

Jimmy Nguyen

9/3/2012 09:02:55 am

I believe that Oobleck is a liquid. I saw that when left alone it acts like a liquid. It takes form to its container and it had that feeling of a liquid. But when I hit it, it hardens then turns back it to a liquid. Every time I slap, punch, or squeeze it, it turns to a solid then back to a liquid. It’s more of like a gel substance when I drip it slowly.

I think that the molecules in Oobleck are like liquids. It has no order, just slides against each other, and forms to the shape of the container. When you punch the Oobleck hard enough the molecules of the liquid won’t slide but lose its energy and compact into a solid. When you don’t do anything to the Oobleck , the molecules would regain its energy and then slide against each like a liquid.

When we place the dry ice in the water it started bubbling and a lot of smoke came out. The dry ice in the water had like a shield of air around it too. I got a ratio of about 1:10 since the dry ice was only about 2 cm and the balloon grew to 9.75 cm. That means the molecules of the gas are 10 time farther apart then the solid.

John Preciado

9/3/2012 09:59:22 am

Part 1:
- I believe oobleck is a solid because the only property that makes it a liquid, is that it takes shape of the container that it is in.
- It is most likely a solid because, if an item where to hit it, it would most likely just bounce right off which is one of the properties of a solid

2. Oobleck acts the way it does because its molecules have a mix of both solid and liquid properties. The molecules are probably still close together like a solid, but they have just enough room to move past each other slightly like a liquid giving oobleck the features that it has.

Part 2:
1. When the dry ice was placed in water, a chemical change occured immediately, with lots of bubbles immediately rising to the surface of the beaker, and spilling over in the form of a gas. It didn't take a lot of time for the entire piece of dry ice to turn into a gas.
2. The ratio that i found was 1:7
3. The ratio was 1:7 because the volume of the original piece of ice 1.6 cm and when it turned into a gas, the volume of the blown up balloon was 7.8 cm. The volume of the area grew seven times its size and it shows that the space molecules can travel in a gas is about seven times larger than that of a solid.

Sierra Renna

9/3/2012 10:01:59 am

Part 1
1. "Oobleck" is both a solid and a liquid. I would be considered a solid when it is being played with and a liquid when it is stationary and not really moving. With my experience with it I learned that when I played with it and smashed it in my hands it would harden and when I just let it chill out it turned into something that I couldn't keep in my hands that well.

2. When “Oobleck” what in a bowl just hanging out you could move the bowl arrowed and it looked like a liquid witch means that the molecules where sliding arrowed each other. They had some space to move and slide arrowed each other. But when you touched it and squeezed it in your hand the molecules tightened and weren’t allowed to move arrowed so much repenting a solid state.

Part 2
1. When I placed the dry ice in water the dry ice started to bubble and make a cloud of smoke that over poured out of the container that it was placed in.
2. 1/2.5=1/12
3. The Simple Raito tells me that when you have a small amount of dry ice it is able to make almost five times more gas.

Fedja Milz

9/3/2012 10:20:57 am

Part I-

I believe that "Oobleck" is a liquid. I think this because when it is sitting idle it flows like a liquid. I noticed that if you compress it for a second or less it will act like a solid, but any more time and it will begin to flow again. I think that this is because under pressure the atoms almost "get stuck" and have nowhere to more. You could think of it like they all get jammed together and cannot move. I think this because it is like a solid when you do this but the very outside layer of it is still a liquid and flowing. This is because the outside layer has nothing to be jammed into because it is not completely surrounded by other "Oombleck" atoms. This explains why it wont splash when you punch it, the atoms have nowhere to move so they just repel the force. When you slowly put something in it the oombleck has time to morph around the object in an orderly fashion and the atoms don't get jammed.

Part II-

The dry ice bubbled a lot when placed in water, and when the bubbles hit the surface a very smokey gas came out of the beaker. We found a ratio of 1:120. This means that for every one part of solid dry ice is 120 times more compact than that same amount in a gas form.

Isak Nuhic

9/3/2012 11:38:30 am

I think "Oobleck is both a solid and liquid but not at the same time. When you dont touch it or move it it acts like a liquid and just stays there, but when you move it or put force on it, it acts as a solid. When i would hold it in my hand it would behave like a solid.

1-2
I think that some of the molecules get pushed to the bottom.
2-1
When the dry ice was put into water the water started to bubble and carbon dioxide started to come out of the beaker. It also started rising to the top of the beaker and when it came out it then started to fall towards the ground.

2-2
1:5.36

2-3
1.100

Grace Ojeda

9/3/2012 12:14:48 pm

Part I:
I think "Oobleck" is acts as both, however it is a liquid because when left alone it acted as one. Only when touch or played with was it a solid. I found this to be my conclusion after it was placed on the shaker when shook it turned into a solid when still is was a liquid.
Proposed Explanation: When Oobleck is touch or there is pressure the molecules get packed together and form a solid. When Oobleck is still it becomes a liquid and does so because the molecules spread out.

Part II: When the dry ice was placed into the water it started to bubble and let the carbon dioxide out. The simple ration was 1:1000 thus making the molecules 1000 times further apart.

Giovanni Cassarino

9/3/2012 12:50:00 pm

1-1: I believe Oobleck can be a solid and a liquid but under different situations. As pressure is applied to the Oobleck, it seems to solidify and dry up. Once you stop applying pressure, it turns into a liquid and returns to its original state.

1-2: One explanation is that when the Oobleck is in a liquid state, the molecules are farther apart, but are able to be manipulated. Once you apply pressure, you are tightly packing the molecules together making it a solid.

2-1: I noticed that the dry ice was bubbling and forcing carbon dioxide to the surface. Once the bubbles popped, it released a thick smoke that poured out of the flask.

2-2: The simple ratio we found out was about 1:1000.

2-3: This simple ratio tells us that the gas molecules are 1000 times farther apart once it sublimates.

David Brown

9/3/2012 12:52:37 pm

Part 1:
Oobleck is a solid when you touch it, but when it is left alone without any pressure it is a liquid. I think Oobleck is a liquid because just observing it the way it is without touching it, it is a liquid.
Explanation: I think the reason that Oobleck is hard when you touch is because the molecules from the cornstarch push together making it hard in that area.
part 2: when you put the dry ice in water it creates a lot of water vapor. the ratio i found of dry ice to vapor, I think was 1 cm to 100cm making 100cm squared for e every 1cm of dry ice.

Kim Enriquez

9/3/2012 12:56:38 pm

Part I:
I think Oobleck is both a solid and liquid.I think this is because when you hold it for a few seconds it remains it's shape however it tends to drip after those few seconds. I noticed this because when I held it into a tight ball it would only last for about three seconds then it would began to rip. I also notice that when it was placed on the shaker it looked like a solid although it was the form of a liquid.

Part II:

When we placed the dry ice in the water it began to dissolve and vapor began to rise. It was really cool to observe. I noticed that the dry ice however to time to dissolve. No matter if it was a small piece or a big chunk it took a while to dissolve. When my partners and I placed the dry ice into the balloon it measured 10 cm the solid carbon dioxide to gaseous carbon dioxide is 1:5 . This meaning that the molecules are 5 times more apart then when it was a solid carbon dioxide.

Tyler Hill

9/3/2012 01:15:37 pm

1. Do you believe "Oobleck" is a solid or a liquid?
- Use your observations.
- What information did you gather from your experience with it that led to
your decision?

I believe that oobleck is a solid that acts like a liquid. I came to this conclusion right before class got out. I went back to look at a plate of leftover oobleck and noticed that it was completely solid. This lead me to believe that it was sort of like cement, it can be mixed with water to make it act like a liquid, but once it is left alone long enough it will harden.

2. Propose an explanation to the mechanics behind Oobleck's behavior. Try to use insight from your understanding of molecules in solids and liquids.

I think that the reason oobleck becomes a liquid when squeezed is because liquids and solids are not compressible. So, when it has time to spread out and sit still it would harden. When somebody squeezed it, because it is not compressible, it would change back to a liquid so it could just be displaced by whatever was squeezing it instead of compressing.

1. What did you notice when you placed a piece of dry ice into water?

The water warmed up the dry ice, converting it back into what I believe is carbon dioxide. This created a fog that rose up from the flask.

2. What simple ratio did you find?

1.77cm as a solid to 13cm as a gas. This translates into 1cm to 7.34cm.

3. What does that simple ratio tell you about the difference in distances between molecules in solids and gases?

In solid form, carbon dioxide condenses into a block of ice with molecules 7.34 times closer together than the molecules in the form of gas.

Jorge

9/3/2012 02:01:20 pm

I believe that the oobleck is a liquid. When I was examining it in class it looked like pancake mix, which is a liquid. It leaked through my fingers when I held it in my hands, like a liquid. however, it did have a solid characteristic, when you hit it your hand bounced bounced back. The harder you tried to penetrate it, the more resistance you felt. That is why I think oobleck is a liquid based on my observations. However, to back up my observations, I'd say that it is a liquid because it's characteristics are what define a liquid. Particles are packed but slide past each other, the oobleck takes the shape of a container, and it has no definite shape.

When a piece of dry ice was placed in the water it started dissolving a lot quicker than water ice. The ice turned into bubbles that were rapidly escaping the water, unlike water ice that mixes with the liquid it's in when it melts. Using the given formulas, we ended up with 1:100 as our ratio. This means that the molecules within carbon dioxide are 100 times more separated when the form of a gas than when in the form of a solid.

Livi Weinstein

9/3/2012 02:39:54 pm

1.I believe Oobleck is a solid and a liquid. When we were working with it, I noticed that when its in motion it turns into a solid but when not in motion it is a liquid. Also when we would make it drip from our hands it would then dry but when it hit the table it would turn back into a liquid.

Part II.

When I put the dry ice into water, there would be stem in the cup of water. It also dissolved very fast. When I placed the dry ice into the balloon it was 10 cm the solid carbon dioxide to gaseous carbon dioxide is 1:5. So the molecules are 5 times more apart then when it was a solid carbon dioxide.

Lukas

9/3/2012 02:48:54 pm

1.1 I believe Oobleck is a solid because it comes from starch, a powdery substance, which is technically a solid. Even though it feels like a liquid, it is not a substance in its simplest form because water has been added. It has undergone a physical change. But, oobleck does consist of probably more molecules of water than of starch. I am not sure of the technicalities that have to be applied in this situation so I can’t really say. Another argument would be that oobleck only turns to a solid when acted upon, therefore by itself it must be a liquid.
1.2 One thing we can say for sure is that the reason oobleck changes from solid to liquid is because some force is acting upon it. Also from my observations I surveyed that oobleck is very good at absorbing shock. When I hit the oobleck there was next to no change in the way it looked, almost as if one was to punch concrete. If it was true that oobleck got harder due to force, than oobleck wouldn’t be as liquefied when you leave it alone due to the force of gravity. I think oobleck may be a substance that has the perfect amount of compression so that it can turn to a solid quickly and a liquid.
2.1 When we placed a piece of dry ice in water mist began to rise very rapidly from the water, and if you looked at the dry ice under water, you could see the bubbles of air going up very fast. I think that’s because dry ice doesn’t mix with water.
2.2 1-100
2.3 This ratio shows that how uncompressed solids are, because even 2x would be a lot. It also shows that if you could compress gas 100x you would get a small amount of solid matter.

Quintin

9/3/2012 04:34:22 pm

I
①　I believe that oobleck is a liquid.
When the oobleck was compressed somehow, like rolling it into a ball between your hands, it acts like a solid, and retaining it's shape, but when it is left still, it will act like a liquid and flow freely. If your pour it into a container, it takes the shape of the container, so it has no definite shape, classifying it as a liquid.

II
①　When the dry ice was put into the water, it went through a rapid change in temperature, which caused the solid to turn directly into a gas (which it does anyway, but was sped up due to the major change in temp.) causing the "fog".

Lindsey Rhoads

9/3/2012 06:07:01 pm

Lab Part 1
I think Oobleck is a liquid because it wasn't always keeping it's shape, like when it was being poured or left alone. One property of a solid is that it keeps it's shape no matter what, if Oobleck was a solid it wouldn't have poured so easily. When it is presented with any type of force, like squishing it in your hand, the Oobleck would keep its' shape, but only for a second before it would ''melt''. If it were truly a solid it wouldn't mold so easily.

Lab Part 2
When we put the dry ice into the water a bubble formed around and and bubbles shot off it rapidly making their was to the surface resulting in a foggy gas. When we put a piece of dry ice that measured 2 cm in diameter into a balloon, we saw the gas starting to release as the balloon expanded. Once all of the ice had turned to gas the balloon measured 10 cm. The ratio of dry ice to carbon dioxide was 1:5. This shows that when dry ice is a gas, carbon dioxide, its molecules are 5x further apart than when the same amount of carbon dioxide is in it's solid form.

Jessie Aguilar

9/4/2012 01:22:56 am

I think the Oobleck is a solid and a liquid at the same time. The reason I think this is because when the Oobleck is left still it turns hard like a solid would be. The reason I think is a liquid too is because when moving the Oobleck it turns slimy like a liquid.

When we put the dry ice inside water it started to desolve slowly and started to make bubbles and a lot of smoke. When we put 1 inch of dry ice in a ballon the ballon grew a lot. our ratio was 1.004796163

tiano lange dei

9/4/2012 01:54:02 am

i believe oobleck is a liquid, because by the feeling and movement, it acts more like a liquid than a solid. Then it depends on the ratio of water you put in.the more water you add the more the moecules moveget to movewhen we put the dry ice in the water it created a lot more vapor/smoke then when it was out of the water, i think the simple ration is 1-100, because 1 part of the ice which in this case is the gas and the liquid which is the water is low. you only needed a little to produce enough compared to the balloon

Sebastian

10/9/2012 01:51:13 pm

1. I think that oobleck is a lot of tiny solids, suspended in liquid. I found that when you quickly touch it, it behaves like a solid. But when you slowly touch it, it behaves like a liquid. This could be because, when you quickly touch it, the solid particles don't have enough time to disperse. Therefore they are temporarily compacted to a solid. But when you slowly touch it, the particles have enough time to slide past one another. Through observing the oobleck sitting in a container, I noticed that after about five minutes the cornstarch starts to settle at the bottom. This shows that the corn starch actually does not dissolve in the water, but is just drifting around in the water.

2. When placed in water the dry ice started to sublimate very quickly. I think this happens because, room temperature water is well above the boiling point of dry ice. So when it is rapidly boiling the dry ice expands, creating co2 bubbles and returning to it's natural state on earth, which is a gas.

3. The ratio that we found was 1-100. This shows that compared to solid dry ice, the molecules occupy about a hundred times more space. This means the molecules are also one hundred times less dense.

Friday's Chemistry Lab

Leave a Reply.

Archives

Categories