Experimental Question #1
Does hot water or cold water freeze faster?
Hypothesis
I believe that the cold water will freeze faster, because the water is closet to the ideal freezing temperature of 32 degrees. Also because molecules are moving much faster in hot water, therefore taking longer to freeze.
Controlled Variables
>Amount of water in cups>Temperature of freezer
>Size of water cups
>Tap water used throughout whole experiment
Materials
>Timer, cell phone>Measuring cup
>Freezer
>Hot and cold water
Data
| 1st attempt | 2nd attempt | 3rd attempt | |
| Cold Water | 40 min | 45 min | 42 min |
| Hot Water | 53 min | 56 min | 58 min |
Conclusion
The cups filled with cold water froze faster than the ones with hot water.
Theory
After doing some research I saw that it is very possible for hot water to freeze faster than cold water. However in the experiment that I set up myself it seemed like the "circumstances" were better for the cold water to freeze faster. The possibility of either one freezing faster than the other is known as Mpemba effect. There are so many factors that go into these experiment, and every one of these factors has an effect on the outcome. Some of the factors are the following, which I am sure were different in all the students experiments; evaporation, convection, frost, and thermal conductivity.Question #2
Does salt water freeze faster or slower than regular water?
Hypothesis
I believe that the regular water will freeze faster than the salt water because, salt water includes molecules that make the freezing temperature have to be much lower. Also this experiment makes me think of the winter time, and how they put salt down on the icy roads to make them safer.
Controlled Variables
>Amount of water, type of water (tap water)>Same freezer and temperature
>Amount of salt in cups
Materials
>Salt water>Regular water
>Cups
>Freezer
Data
| 1st attempt | 2nd attempt | 3rd attempt | |
| Salt Water | 80 min | 76 min | 78 min |
| Regular Water | 47 min | 48 min | 45 min |
Conclusion
The regular water froze much quicker than the salt water.Theory
The salt water froze much slower than the regular water because saltwater doesn't even begin to freeze until the temperature reaches six degrees BELOW zero Fahrenheit, whereas fresh water freezes at thirty-two degrees above Fahrenheit.Question #3
Does hot water or cold water boil faster?
Hypothesis
I believe that the hot water will boil faster because it is closer to that boiling point of 212 degrees Fahrenheit. I think that the cold water would absorb the heat faster, therefore boiling. Whereas the hot water would take longer to absorb the heat.Controlled Variables
>Amount of water in pots>Same stove and temperature
>Same pot used to boil all the water
Materials
>Stove>Hot and cold water
>Pots
>Timer
Data
| 1st attempt | 2nd attempt | 3rd attempt | |
| Hot Water | 3 min 30 sec | 3 min 15 sec | 3 min 34 sec |
| Cold Water | 4 min 34 sec | 4 min 40 sec | 4 min 36 sec |
Conclusion
The hot water boiled faster than the cold water.Theory
The hot water boils faster because I believe that the molecules in the water are already up to speed, therefore it takes them a less amount of time to actually boil. Whereas the cold water has very slow moving molecules.Images of atoms that make up water molecules:
Video showing how water molecules are arranged in the
three states of matter for water-
Link:
https://www.youtube.com/watch?v=Gxwj24mREyA
Scientific Method
-How each step correlates to your own experiments
Step One: Ask a Question
-Starting off an experiment with a question is an easy way to get the research flowing, because in the end we are trying to answer this exact question. For activity one, the questions were clearly stated; Does hot water or cold water freeze faster?, Does hot water or cold water boil faster?
Step Two: Make Observation and Conduct Background Research
-Making an observation is an important part to an experiment, not only that but doing some background research before you make this observation is even better. For me, I read through the PowerPoint notes and the book before I made my hypothesis. It made my hypothesis have a bit more accuracy to it, and was not just a guess. Some of the common myths of today's society kind of threw me off, because there are so many rumors about water, and what boils quicker and such. This gave me even more of a reason to do some research beforehand.
Step Three: Propose a Hypothesis
-Like I stated above I used a lot of the research that I did before conducting the experiments to help propose my hypothesis. I did not know for sure if my hypothesis was correct, however based on my knowledge it was my best educated guess. This hypothesis becomes important in an experiment because in the end you state if your hypothesis was correct or incorrect. Also, you can learn in the end why your hypothesis was wrong or right, which is the whole point of the experiment.
Step Four: Design an Experiment to Test the Hypothesis
-The experiment is where you get to put everything to work, and to also see if your hypothesis was correct or not. During an experiment it is important that you are constantly recording data, and in this case taking pictures to show what you learned. Also there are variables that have to absolutely be the same to make the experiment more accurate, such as how I used tap water throughout my entire activity one. The data then gets represented in a graph, and your conclusion will then state what you learned and if your hypothesis was correct or not.
Step Five: Analyze Data
-After doing the experiment and getting a chance to look over the data, this is the rewarding and learning part. The data is a whole story in it's own. You also have to look at if there were any factors that are going to affect the data, or exactly how accurate your data is. It is exciting getting all done with an experiment and getting to look at all the hard work and data that comes out of it.
Step Six: Communicate Results/Accept or Reject Hypothesis
-There are many ways of communicating your results from an experiment, however for this particular one we had to create a blog and share our data with the class. This is a more individualized way of sharing data, being able to organize and display our works with others. The fun part about these blogs is we could really do what we wanted, and spice things up a bit. In the end is also where you have a chance to accept or reject your hypothesis. All that matters throughout the whole experiment is that you learn something new, and most likely that is the case. I learned many new facts after doing the following experiments, like I said before that prove the old myths wrong.
Repeatability of Experiment and Averages
The importance of doing the experiments above more than once just assured that the answers and data were correct. Each experiment was done three times, and then below I am going to state the averages for each experiment. It adds more confidence that things were done right. The more times that you do an experiment and then take the average the more accurate your data is going to be.
Question #1: Does hot water or cold water freeze faster?
Hot water- 55.66
Cold water- 42.33
Question #2: Does salt water freeze faster or slower than regular water?
Salt water- 78
Regular water- 46.66
Question #3: Does hot water or cold water boil faster?
Hot water- 3:26
Cold water- 4:36
Experiment and Connections to Real World
In this first activity we covered many topics such as; molecules, physical properties, chemical properties, physical changes, classification of matter, states of matter, atoms, and many more. These experiments that I conducted were crucial in changing the state of matter, and I got to watch those changes myself. Also I had to keep data, tracking how long these changes took to take place. It was interesting taking an up close and personal look at the different states of matter, which is something I have never done before. I also included accuracy into my experiments, which meant doing things more than once.
In the end, most of my hypotheses were wrong, but it was interesting seeing why there were wrong. Also it was interesting watching them being proved wrong right in front of my eyes. I also made a point to do all my experiments three times in order to assure accuracy. It was also another positive because I also took an average from my data, which also made coming to a conclusion much easier. In the future I can definitely see the importance in repeating operations such actions. The experiments were also interesting because as my mom was watching she would state what she thought would happen, and the opposite would actually take place, it was pretty cool to prove her wrong.
The experiments that took place can easily and effectively be applied to real world application. One main way that I can think of is if you are in a rush making dinner, and you need to know if hot or cold water will boil faster, which in the end will just save you time. Another way this information that I learned could be applied to real life situations is when I am trying to make ice in a hurry, I will know weather to use hot or cold water.
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