pH Lab Report

Guiding Question: How can you determine the strength of an acid or a base uasing a cabbage indicator?

Hypothesis: I believe that when the litmus paper is put into an acid, it will turn red, and if it put into a base, it would become blue. The intensity of an acid or a base can be determined by the intensities of the two colors shown on litmus paper. Also, the neutral solution will probably turn green. Some examples of substances that will probably turn out to be acids will be lemon and oranje juice, HCl solution. Some liquids that I am expecting to be bases are most of the cleaning supplies that could be found around the house. Substances that are expected to act very gently, and with little affects, such as baby oil, will probably go green, and turn out to be neutral.

The Variables: The controlled variable of this lab is the amount of indicator and the amount of each substance that is being used. For this lab, we decided to use ten drops of cabbage juice indicator and five drops of substance. The manipulated variable are the different substances that we will use, to test their itensities. Finally, the responding variable is the color that would change when a different acid or a base is added to the indicator.

Materials:

• Cabbage Juice Indicator
• Oil
• Windex
• Wine Vinegar
• Cedevita
• Coca Cola
• Milk
• Guarana
• Multivitamin
• Green Tea
• Pipette
• A test plate

Procedure:

1. Cut up the cabbage into small pieces.
2. Put the pieces of cabbage into extremely hot water, and let the color of the cabbage dissolve, until the water has turned very dark blue/purple.
3. Take the cabbage out of the indicator, and, with a pipette, put 10 drops into the small holes inside the test plate.
4. Using a new pipette, put five drops of a wanted substance into one of the holes.
5. Observe the change in color, as well as the color's intensity. Write down your observations.
6. Repeat the same procedure for every new substance.Remember to use a new pipette for each substance, so that you do not mix the liquids with each other.

Data Analysis and Observations:

Oil: The dense liquid sank to the bottom of the indicator, not changing the color of the indicator a great deal, just making it transparent in certain spots. The substance is therefore neutral.

Windex: The liquid instantly just mixed with the indicator, turning it into quite a bright turqoise blue. This shows that windex is a medium to stronger base.

Wine Vinegar: The liquid turned the indicator a bright, light pink, This would mean that wine vinegar would be a medium acid.

Cedevita: Cedevita turned a very faint pink when mixed with the indicator, which would mean that it is a light acid. What was interesting was that before we mixed the Cedevita, if you looked at the mixture from the side, it had two levels of color, yellow and pink.

Coca Cola: Coke is an extremely light acid, because the red is very faint; it is almost transparent.

Milk: Milk is a very light acid, because the indicator turned into a very light purple. The mixture was also quite cloudy, not as clear, like the others.

Guarana: Guarana is a medium to strong acid, because the color of the indicator turned a very strong pink,

Multivitamin: We got an almost same reaction as we did with the Cedevita- a transparent, light pink.

Green Tea: It was quite surprising for us that the green tea turned into a very faint color of red, meaning that it is a light acid.

Conclusion: To repeat, the guiding question for this lab was "How can you determine the strength of an acid or a base uasing a cabbage indicator?". I believe that my hypothesis was partially correct. The intensity of an acid can be determined by how strong the red/pink color is. The stronger the color is, the intensity, as well as the number on the pH scale will be higher. As for the base, the more intense the blue is, the stronger the base will be, and the lower the number on the pH scale. However, when a neutral substance is added to the indicator, it doesn't turn the indicator red, it just simpy doesn't change it's color at all.

Further Inquiry: During this lab, I believe that there weren't any errors, because it was quite a simple lab, and the only thing we had to look out for was the controled variable (making sure that the exact amount of drops is added to the indicator). However, I do wonder whether the amount of a certain substance will affect the intensity of the color the indicator turns. My opinion, or hypothesis, is that it won't change the indicator much, because the amount of a substance doesn't change it's chemical properties, and doesn't affect it's pH.

Baking Soda and Vinegar Lab Report

Baking Soda and Vinegar Lab Report

By: Teodora Milenkovic 8A

November 29^th, 2011

The guiding question: How does the amount of baking soda affect the length of its reaction with vinegar (acidic acid)?

Hypothesis:

I believe that the smaller amounts of baking soda such as the five grams and ten grams will react slower than the larger amounts. I think this because the larger amounts of sodium bicarbonate will completely “absorb” the vinegar with all of its powdery texture. This will cause the reaction to be much faster, because after the soda bicarbonate “absorbed” the vinegar, it wouldn’t have much acetic acid left to actually react with. However, with the smaller amounts, the two materials are more balanced, in my opinion, and therefore the reaction will be much clearer and much longer.

What were the variable in this lab?

The controlled variable would be the amount of vinegar that is used for each reaction, because if the amount of vinegar was changed, the lab would no longer be fair and the data would not be valid. The independent variable would the soda bicarbonate, because we are constantly changing how much of it is being added to the vinegar. This is what essentially causes the different reactions that could be produced. Finally, the dependent variable is the length of the reaction(s) that should be measured in seconds

Materials:

·         Vinegar (acetic acid)

·         Baking Soda (soda bicarbonate)

·         Pipette

·         Test tube

·         Paper towels

·         Stopwatch

·         Scale

·         Spoon

·         Safety goggles

Procedure:

1.       First, you have to gather all the supplies that you need, and you also need to create a table, in which you will put all your information in. In this table, you should include a total of three columns. The first column should show tell about the amount of baking soda, the second one about the observations during and after the reaction, and in the third column the time for each reaction should be written.

2.       Pour 20 milliliters of vinegar into a test tube.

3.       Measure five grams of baking soda, and pour it inside the test tube with a spoon.

4.       The moment you put the baking soda into the acidic acid, start the stopwatch.

5.       Keep measuring the length of the reaction until the bubbling, fizzing, etc. stops (when the reaction is over).

6.       Put in the time, as well as the observations into your data table.

7.       Repeat the steps above for each amount of baking soda that you use for the rest of the reactions (10g, 20g, 30g, and 40g).

Data Analysis:

Amount of baking soda (g)	Observations during and after the reactions	Time for each reaction (s)
5	The mixture looked a little bit like elephant toothpaste. It was very foamy, and it spilled over the test tube quite a lot. After the reaction, only vinegar was left in the test tube, with a bit of foam left on top of it, probably because of the density.	32.5
10	The mixture was fizzier than the previous one, and it also lasted shorter. The state after the reaction was similar to the previous one, except the fact that the vinegar left at the end had more bubbles left on top of it.	29.12
20	The mixture was VERY fizzy, and quite a lot shorter than the previous ones.	23.22
30	The mixture didn’t exit the tube at all, it just bubbled a lot, and that is why it was very difficult to see when the reaction was over	20.94
40	This mixture didn’t really react, it just fizzed a little bit, and it than sunk to the bottom of the test tube, which was quite surprising.	17.93

Below is the graph of my results, which shows how the length of the reaction increases with the amount of sodium bicarbonate:

One of the most difficult parts of this lab was figuring out when the reaction was over, and when the stopwatch could be stopped. That is when it is important to pay close attention to what we have learnt in class, and what are some of the signs of chemical reactions. Some of the signs of a chemical reaction has taken place during this lab was the fizzing that occurred, as well as the foaming in the first reaction. When the foaming and the fizzing have stopped, the chemical reaction has probably taken place, and some bonds were broken, while new ones were created.

By examining the results that were gathered during this lab, it is not difficult to realize that it is not only the different chemical formulas that affect the chemical reactions, it is also the amount of atoms that are mixed with each other. If there are two much atoms of one substance mixed with another, it is possible that the results won’t be what you anticipated them to be.

When a greater amount of baking soda was added to a much smaller amount of vinegar, it looked as though the baking soda completely dried up the vinegar, and the reaction was hardly even noticeable. However, when only five grams of baking soda was mixed with vinegar, the reaction was much more visible and effective. This could probably be because the bonds between the acid, the sodium, and carbon were much easier to form when the mixture of the two substances was balanced, meaning that the number of the atoms made the bonds easier to form.

Even though we didn’t measure the temperature change that could occur during this experiment, it could be predicted that an exothermic reaction took place, because of the fizzing that was constantly happening in almost every reaction. Usually, when a substance fizzes, it is a sign that some sort of energy or heat has been released.

Conclusion:

                The guiding question during this lab was “How does the amount of baking soda affect the length of its reaction with vinegar?” The hypothesis was partially correct, because it was mentioned that the larger amounts of baking soda will probably take longer to react with vinegar, because they would absorb all the acetic acid. However, the faster reaction in the larger amounts of baking soda is the fact that the atoms in both substances are not quite in balance with each other, so obviously the reaction wouldn’t be what should be expected (fizzing, foaming, etc.)

Further Inquiry:

                When this lab was being done, I wondered quite a lot about whether the results would be the same if the variable that we kept the same was the amount of soda bicarbonate, and the variable that was being changed would be the amount of vinegar. It would be really interesting to conduct those tests, as well. It would be interesting to see and compare the results, especially because of the different textures of these two substances. Baking soda is quite powdery, while vinegar is a liquid.

If we could conduct this experiment again, I believe that we would have paid a little bit more attention to the actual reaction, and what was happening in the test tube, rather than just timing it and observing the after-effects. Also, we should have worn safety goggles, because there was a chance something could have happened, because we weren’t cautious enough.

               

Birds delay migration

Site: http://www.bbc.co.uk/nature/15783321
Author: Victoria Gill

Scientists are saying that the birds that usually stay in Northern Europe are changing the time of their migrations to warmer areas.  Those birds include geese, swans, as well as many other species. It is believed that some migrations have been delayed by up to a month compared to the previous thirty years! Research has also shown that the number of some very common birds in England, as well as Denmark, Ireland, and other Northern countries is decreasing, because a lot of them "do not fly as far".

In Finland, many birds were counted ever since 1979, to create what is commonly called a "migration census". This information can tell scientists when different types of birds are migrating to warmer countries, from Finland. Over the last three decades, scientists were able to come to a conclusion that many migration have been delayed in the past few years. Six out of fifteen species of birds that were observed have migrated much later than they should have. Some of these birds include the tufted duck and the greylag goose. Other studies also show that the temperatures in the sea and other bodies of water in the north of Europe have been increasing even more then the air temperatures. This can be partially the cause of delayed migration, because with the rising of the water temperatures, the more fish and other food there is for the birds up in the north. This is causing very big changes in the food chain(s), and the ecological effects are becoming very big.

I believe that the changes with the migation of birds have a lot to do with what we are doing to ur environment, and how we are treating our planet. The greenhouse gasses that are constantly being released from many factories and grand industries around the globe are cauing major global warming. This is not only affecting our well-being on the Earth, but is also affecting the innocent animals, such as birds. The warmer temperatures can confuse the birds, cause some of them to stop migrating completely, and create major negative changes to the delicate balance of food chains in our ecosystems. It is horrible that we are doing this, and it needs to stop soon, before even more creatures are hurt. If we do not reduce the amount of pollution, many different species will suffer, and that is very unfair to them, as well as quite dangerous for the other animals in the biosphere.

Not Seeing Sunspots...

Site: http://www.sciencenewsforkids.org/2011/06/not-seeing-sunspots/
Author: Stephen Ornes

The sun is very important for our siruvival from many different aspects. Without the sun, we would freeze on Earth, we would have no food, and we would have much different calendars. Because it is so imperative for our life, scientists are constantly watching the sun, trying to see whether there were any chages to it's surface, temperature, etc. The solar cycle lasts for 11 years, and then changes. When one cycle begins, many spots can be seen on the sun. Most of these spots, some the size of Jupiter can be caused by the magnetic activity that constantly takes place in the universe. Even ancient astronomers have been looking at the spots that appear on the sun for more than 400 years.
However, studies show that this year, the cycle of the sun might not start at the predicted time this year. Scientists say that they cycle could be delayed this year, but that there is also a possibility that it might not happen at all. They haven't been noticing the usual changes the sun goes through when the new cycle of the sun is supposed to start. It is possible that the sun will be going into "hibernation", meanining that it won't be as powerful as it usually is for a few years, or decades. The last time this happened was between 1645 and 1715. Scientists are, however, uncertain in what ways this could affect the climate and weather conditions on Earth, as the atmosphere of our planet has changed dramatically over the last 300 years, because of the greenhouse gasses. Many studies involving the sun's magnetic activity were conducted, and they showed that the magnetic field has gotten much weaker over the past few years. However, the information that was gathered is not enough to determine whether "the sun will be taking a long break".
To me, this doesn't seem very frightening, because scientists are expecting for this change to be temporary. However, I cannot help but wonder whether this could cause a smaller, less severe version of the Ice Age, because of the very cold winters that could take place. As for the scientists' further research, I think that it would be cool if they investigated whythe sun is gowing through such changes, and why the solar cycle is delayed. Maybe, the changes the sun is going through can affect not only the sun itself, but also the moon, and other stars near it.

World's Lightest Material!

Site: http://www.sciencedaily.com/releases/2011/11/111117154643.htm
Date of publication: November 17th, 2011

A team of scientists from the California Institute of Technology have found a newly developed material that is the lightest on Earth. This material has a density of 0.9 mg/cc, and is one hundred times lighter than Styrofoam. The architecture and the design of this material is very unique, and it is what scientists call the "micro-lattice" design. The micro-lattice design makes many hollow, tiny tubes, which are separated by "walls" that are 1,000 time thinner than one human hair. What is very interesting about this material is the fact that it is made up of 99.99% air, and 0.01% is metal. This metal has very high energy absorption, and all the other physical and chemical properties of a metal. Many architects are starting to become very excited about this unique metal, because by using this metal, more weight-efficient buildings could be designed. Nano and micro scales are starting to be used in science, as well as architecture.

I personally think that this is fascinating, and that it is amazing that such a light material could be found. However, I am a little bit skeptical about whether they build any actual models of buildings out of such a light material. After all, it is made up of mostly air, and that could be quite difficult to handle. What was especially interesting, in my opinion, was the fact that this metal could be placed on top of dandelion fluff, and not damage it in any way. However, I am wondering whether they would be able to create this metal to a larger scale, and be able to use it for anything efficient. When I read this article, I immediately thought about what type of metal they used, because there are some metals that are not very light, at all. Also, if this light metal was created out of an alkali metal, I wondered what would happen to all the air within the material if it was dropped into water. The metal would combust, but I do not know what would happen to 99.9% of air.

Where's the evidence?

Guiding Question: What are some signs that a chemical reaction has taken place?

Hypothesis: I believe that there are many signs that show chemical change or chemical reaction. The mixture or the color of different elements could change color. The state and the tempereature could also change. It would become colder or warmer, depending on the chemical reaction. Another sign that a reaction occured would be bubbling or combustion (explosion).

The Materials Used

We used many different types of materials for this lab, as many different experiments took place. We used baking soda, vinegar, sugar, copper sulfate, sodium carbonate, zinc, hydrochloric acid (HCl), calcium chloride, aluminum foil (copper), starch and iodine.

Data table with all observations:

Reactions	Observations Before Reaction	Predictions	Observations During Reaction	Observations After Reaction
Baking Soda (Soda bicarbonate) + vinegar	Vinegar looks like water, but has a strong alcohol scent. Baking soda is a white powdery substance.	I think that once the two substances mix, a white liquid could form.	The moment we put vinegar into baking soda, the mixture started foaming and rising up the test tube.	The mixture turned powdery and stuck to the sides of the test tube.
Sugar + heat	To provide the heat, we used a wax candle, and we put the sugar into a tin foil.	The sugar will probably become quite warm and caramelize.	During the reaction, smoke was released, and it had a strong smell. The sugar turned brown, and while it was over the flame, it was a brown substance, which had a gooey consistency.	After a while, the caramel cooled down, and it completely got stuck onto the foil, as it went back to its original state of matter.
Copper Sulfare + Sodium Carbonate	The sodium carbonate is a colorless liquid, while copper sulfate is bright blue.	I think that the mixture will just turn a light blue color.	The mixture precipitated, and turned into a form of a solid. Also, the mixture turned light piercing blue, probably because the copper sulfate into the sodium carbonate.	The solid broke apart, and the denser piece went to the bottom of the now colorless liquid, while the less dense one floated at the top.
Zinc piece + Hydrochloric acid (HCl)	Zinc is a solid, yet powdery metal, and HCl is a water-like liquid, that is very toxic.	I believe that the zinc will probably just start fizzing.	The zinc started getting all bubbly and it started fizzing. The smell was really disgusting, because hydrogen gas was released. The zinc turned black and dissolved.	After the reaction, the zinc was still fizzing, but the HCl liquid has turned completely white.
Calcium chloride + Sodium Carbonate	Both liquids look like water and are completely see-through (colorless). However, both have a distinct smell.	I think that nothing interesting will happen, and that the two liquids will probably form another colorless mixture.	The two liquids formed a white, cloudy mixture, and they also precipitated.	The mixture pretty much remained the same, the only difference was the fact that the solid fell to the bottom of the tube.
Copper Sulfate + aluminum foil	Copper sulfate Is a bright blue liquid, while the aluminum foil is a shiny, bendable, sheet of metal.	I am not really sure about what could happen, but the aluminum foil could dissolve.	The foil started getting bubbles on it, and during the reaction it looked white, and small parts of the foil fell off when I shook the test tube.	Two days after the reaction took place, we found out that the foil completely changed it’s color and it turned crimson red.
Starch + Iodine	The starch is a white powder used for baking, while iodine is a very red liquid, that looks like blood.	I think that the two materials won’t mix, because they have a lot of different physical and chemical properties.	When iodine and starch DID mix, the liquid was a purple color. The more iodine we added, the darker it got.	The purple started settling at the bottom of the test tube, while the rest of the liquid went back to being colorless.

Analysis of my results:

1. How do the results of each reaction compare with your prediction?
Most of my predictions were right, even though some chemical reactions really took me by surprise. When the aluminum foil and the copper sulfate, I really didn't expect the foil to become so red, and to start falling apart inside the tube. Also, the fomaing of baking soda and vinegar caught me by surpsrise, as I didn't expect such a severe reaction between these two common substances. However, we knew in advance that some substances could e very toxic and reactive, so we could know what to expect.
2.  How did you know when each reaction was over?
In most cases, it was obvious to see when the reaction was over. If the mixture stopped bubbling, that meant the reaction was over, and that the chemical changes have aleady taken place. Also, if the color completely stopped changing, we would know that the reaction is over. The end of a reaction could be marked by the cooling down of a mixture, or the stop in temperature change.
3. What was the evidence of a chemical reaction in all results?
The evidence of a chemical reaction was what was left of the reaction after it took place. When the sugar was burned, the evidence of a chemical reaction was the caramelized sold sugar that was stuck to the aluminum foil. It's color and state had been changed. Another evidence of a chemical reaction would be the newly-formed mixture left when two or more materials mix. This mixture could have a different color, smell, etc.
4. Were there any endothermic or exothermic reactions?
Exothermic reactions took place throughout this lab. Exothermic reactions that can be explosive and they release heat. One example where heat and smoke was released when zinc was mixed with hydrochloric acid. When the metal started fizzing, the mizture released warm energy, as well a hydrogen gas.  However, during this lab, no endothermic reactions were experienced, since nothing cooled down dramatically.
5. Were the products always the same as what you started with?  How do you know?
The products were never the same as they started with. In a chemical reaction the whole chemical structure of molecules changes, and they can never go back to their original states. I know that the substances and mixtures are not the same because their color changes, their original state cannot be retrieved, and they could have strong scents.

Conclusion:

What are some signs that a chemical reaction has taken place? There are many sings that can show that a chemical reactions occured. Firstly, there could be a color change in the mixture. The texture could change, as well, so the way something feels changes. We also know a chemical reaction has taken place when a new substance is formed. For example, when zinc was mixed with hydrochloric acid, hydrogen gas was released. We can also know that a chemical reaction has taken place when something combusts (explodes) or precipitates. Most of the reactions came to the end, because once the bonds create, and once the elements are mixed with each other, they stop reacting.

Further Inquiry:

If I could change anything about this lab, I would probably add some more known substances, to see how household items, and items that are familiar react with each other. This would have probably made the lab more interesting. However, overall, I believe that this was one of the most interesting labs we did, and it was one of my personal favorites.

Chemical Reactions!

1. http://www.youtube.com/watch?v=hVK9Om4wzBM
Once bromine was put into the alcoholic substance, the alcohol had to be shaken a little bit, in order for the bromine to dissolve better. Firstly, the white bromine started dissolving into the alcohol turining it yellow. The, towards the end, it seemed as though the bromine started burning, because a very powerful, bright orange gas was released. It looked quite toxic. Finally, once the chemical reaction was over, only a very light yellow liquid was left behind. We know a chemical reaction has taken place, because a gas was released and there was a significant color change.

2. http://www.youtube.com/watch?v=8ypUVpwgcAA&feature=related
A small piece of lithium was put into water. The moment lithium touched the water, it turned into a flame that quickly started moving across the water's surface. Before it started burning, though, the lithium also sizzled severely. However, the flame went away quickly, as well. A smoke was, obviously, released. We know that a chemical reaction has taken place, because a the metal combusted.

3. http://www.youtube.com/watch?v=896vJj6eWYw&feature=related
This was a chemical reaction between ceasium and water. Just like all alkali metals, ceasium had a severe reaction once it got in touch with water. It combusted, and looked much like a firework. The actual combustion was quite short, but the stregnth of the chemical reaction was shown by the amount of smoke that was produced. The color of the "firework" was quite bright orange.

4. http://www.youtube.com/watch?v=qRmNPKVEGeQ&NR=1
This chemical reaction was between potassium and water. The potassium reacted in a similar way to lithium, except the actual flame lasted much longer. What I found quite interesting was the fact that that the flame died down VERY quickly, and towards the end of the video, it seems like the potassium makes a popping sound, and explodes out of the water.

5. http://www.youtube.com/watch?v=vJslbQiYrYY&NR=1
The next video shows sodium in water, and, in my opinion, this is one of the coolest reactions! Firstly, the sodium is dropped into the water, and it automatically creates a yellow flame that is floating in the water. Then, once you start thinking that the flame might start dying down, a big combustion happens, that sends the water flying everywhere! I believe that the sodium was able to break the container, as well, if just a tiny bit more of it was added.

6. http://www.youtube.com/watch?v=_Pk6s1MbszA&feature=related
In this experiment, a gummy bear is added to sodium chlorate. Once the gummy bear was dropped into the test tube filled with sodium chlorate, the tube started fuming, and it alomst appeared as though it was glowing! You can deffinetely tell a chemical reaction took place, because the combustion was obvious. At first, the flames and the glowing happened only at the bottom of the tube, but it rapidly advanced to the whole tube, as well.

7. http://www.youtube.com/watch?v=zrNA8-eipGE&feature=related
Finally, this is a really fun experiment, that looks super interesting! So, the person put water inside a cup, and hooked a light that sent electricity through the water. The whole cup started glowing! But, to make it more interesting, the person added a blue food dye and stirred it with the water. This created a really cool turquoise color that glowed just like a real lightbulb!