Blog Activity 1

Experiment 1:

Question: Does hot water boil faster than cold water?

Hypothesis: Hot water will boil faster than cold water.

Materials used:

·         1 cup of water

·         1 thermometer

·         1 small pan

·         Stovetop

Variables: The temperature of the water is the independent variable while the time it takes to boil is the dependent variable.

Theory: Hot water boils faster than cold water.

Results:

Does hot water boil faster than cold water?
	Starting Temperature (F)	Boiling Temperature (F)	Time it takes to boil (Min)
Hot	128	205	1:01
Cold	40	205	3:10
Hot	133	210	1:01
Cold	42	209	3:06
Hot	134	205	1:06
Cold	44	208	3:04

Reproducibility: This experiment was done 3 different times and had close to the same results each time. Every hot water seemed to boil between 1 minute and 1 second to 1 minute and 6 seconds. The cold water seemed to take a couple minutes longer but seemed to boil around the same time. The boiling temperature only varied by 5 degrees Fahrenheit. 

Experiment 2

Question: Does cold water freeze faster than hot water?

Hypothesis: Cold water will freeze faster than hot water.

Materials used:

·         2 tablespoons cold water

·         2 tablespoons hot water

·         2 bowls

·         Freezer

Variables: The temperature of the water is the independent variable while the time it takes to freeze is the dependent variable.

Theory: Cold water does not always freeze faster than hot water.

Results:

Does cold water freeze faster than hot water?
	Starting Temperature (F)	Freezing Time (Min)
Cold	38	42
Hot	123	38
Cold	39	41
Hot	125	44
Cold	40	43
Hot	128	37

Reproducibility: This experiment was not as accurate as the first one. It seems that hot water does not always freeze faster than cold water, but it is possible. The first and last showed that hot water freezes faster, but the middle experiment shows the opposite.

Experiment 3

Question: Does salt water freeze faster or slower than regular water?

Hypothesis: Salt water will freeze slower than regular water.

Materials used:

·         2 tablespoons water

·         2 tablespoons salt water

·         2 cups

·         Salt

·         Freezer

Variables: The salt is the independent variable while the time it takes to freezes is the dependent variable.

Theory: Salt water freezes slower than regular water.

Results:

Does salt water freeze faster or slower than regular water?
Starting Temperature (F)                      Freezing Time (Min)
Salt water	50	1 hour  5 min
Regular	50	59 min
Salt water	50	1 hour 3 min
Regular	50	53 min
Salt water	50	1 hour 4 min
Regular	50	55 min

Reproducibility: This experiment showed that salt water freezes slower than regular water. All of the freeze points seemed to be around the same time and the salt water always took quite amount of more time than the regular water. 

 Scientific Method Process: The first process in the scientific method is to form a question. In these experiments, the questions were if hot water freezes/boils faster than cold water and if salt water freezes slower or faster than regular water. The second step is to form a hypothesis, or an educated guess on what you think will happen. My hypotheses were that hot water would boil faster than cold water, cold water would freeze faster than hot water, and that salt water would freeze slower than regular water. The third step is to conduct an experiment that would test your hypothesis. My experiments were to boil cold and hot water and see which one boiled faster, to freeze hot and cold water and see which boiled faster, and to freeze normal water and salt water at the same time to see which froze faster. The fourth step is to draw conclusions and analyze the data. I did this by putting it into a graph and redoing each experiment 3 times to make sure the data matched up.

http://www.youtube.com/watch?v=v12xG80KcZw

Knowing the scientific method is very important when it comes to experimenting new things. The scientific method is a clean cut, simple way to put together ways to answer specific questions. The steps of the scientific method include coming up with a question, forming a hypothesis, or educated guess on what will happen next, testing that hypothesis in an experiment, analyzing the information from that experiment, and figuring out the conclusion to that question. By missing out of these steps we lose a very important step such as what we are asking, what we thought before we found out, how we found out, or what the actual answer is.

In the experiments I chose, I boiled hot and cold water to see which would boil faster. I froze hot and cold water to see which would freeze faster, and I froze regular water and salt water to see which would freeze faster. The hot water ended up boiling faster, the cold water and hot water froze faster in different times of the experiments, and the regular water froze faster than the salt water. My hypotheses for two of them were correct. However, for the hot water to freeze faster than the cold water, that blew my mind, and I'm sure I'm not the only person who has guessed that. 

When hot water freezes before cold water it is known as the Mpemba effect. This is when hot water loses some of it's water to evaporation while in the cooling process; therefore there is less water to freeze than the water that is already cold. Another reason for it is that the warm water may have more air movement than the colder cup, drawing more heat energy away from it more effectively. This is the same for the boiling experiment. Water uses heat energy to boil, and by the warmer water initially having more heat energy to begin with, it will take less time that the cold water that has to create all of its heat energy. For the salt water experiment, my assumption as to why it wouldn't freeze as fast is because of what I see every single winter on the sidewalks. We throw salt on the sidewalks to melt the ice, therefore, the ice in a freezer would also take longer to freeze as the salt is melting it every time it begins to. 

Koning, Ross E. 1994. Water and Water Movement. Plant Physiology Information Website.

"Fizzics Education "Does Hot Water Freeze Faster than Cold Water?"" Fizzics Education "Does Hot     Water Freeze Faster than Cold Water?" The Butterfly Nebulae, n.d. Web. 09 July 2013.