Chemistry Activity 1

Experiment #1

Question: Does hot water or cold water boil faster?
Hypothesis: Hot water will boil faster.
Materials Needed:
* Stove
* 2 small pans
* 3 cups of water
* Thermometer
* Hot water
* Cold Water

 

 

 

Boiling Point for Cold and Hot Water
	Starting Temp in Fahrenheit	Boiling Temp in Fahrenheit	Time Water boils in Minutes
Hot	130	207	1:15
Cold	37	206	3:14
Hot	132	208	1:12
Cold	35	207	3:15
Hot	129	205	1:18
Cold	36	207	3:14



 



 

 

Variables and Theory: The independent variable is the temperature and the amount of minutes it takes the water to boil is the dependent variable because it depends upon the temperature. 

 

Reproducibility: The experiment was done 3 different times.  Each time the boiling point of both the cold and hot water only varied by just a few seconds.  The cold water took about 2 minutes longer to boil than the hot water did each time. 

 

 

Experiment #2

 

Question: Does Hot or Cold Water freeze faster?

Hypothesis: Cold water will freeze faster

Materials Needed:

* 2 ice cube trays or cups

* Timer

* Thermometer

* Freezer

* Cold Water

* Hot Water

 

 

Freezing Points of Cold and Hot Water
	Starting Temp	Time Water Freezes in minutes
Hot	130	40
Cold	39	35
Hot	128	40
Cold	37	37
Hot	129	42
Cold	39	38

 

Variables and Theory:  The starting temperature of the hot and cold water is the independent variable, while the time it takes each of the different waters to freeze is the dependent variable because it relies on the starting temperature.  The theory is that cold water freezes faster than the hot water. 

 

Reproducibility: This experiment was done 3 different times and each time the hot only varied by 2 minutes and the cold varied by 3 minutes at the most. 

 

Experiment #3

Question: Does salt water freeze faster than normal water?

Hypothesis: Salt water will freeze faster than normal water

Materials Needed:

* 2 cups

* 1 teaspoon salt

* Water

* Freezer

* Thermometer

 

 

One cup with salt in it.

 

 

Cup without salt in it starting to get frozen. 

 

Freezing Points of Salt Water and Normal Water
	Starting Temp	Time Water Freezes in minutes
Salt Water	45	59
Normal Water	44	48
Salt Water	44	59
Normal Water	44	45
Salt Water	45	57
Normal Water	45	47

 

Variables and Theory:  The starting temperature of the water is the independent variable while the time that it takes water to freeze in minutes is the dependent variable.  Normal water freezes faster than salt water.

 

Reproducibility:  This experiment was done 3 different times, each time the normal water froze faster than the salt water.  The normal water generally froze 10 minutes before the salt water. 

 

Atoms that make up the water molecule:

 

http://lc.brooklyn.cuny.edu/smarttutor/corc1322/atomex.html

 

Link to a Video on the different states of matter:

http://www.youtube.com/watch?v=KCL8zqjXbME

 

 

Scientific Method Process: 

The first step to the scientific method process is to ask a question.  The questions asked were, does hot water boil faster than cold water?, does salt water boil faster than normal water? and does hot water freeze faster than cold water.  Then after your questions are set, you must decided upon a hypothesis, what you think will happen during the experiment.  My hypothesis for each experiment were that cold water would freeze faster than hot water, hot water would boil faster than cold water, and that salt water would freeze faster than normal water.  After those are both set, then you must test your hypothesis through experimentation.  I did this by repeating each experiment 3 times and by boiling cold and hot water through experimentation of recording the temperature of the water at the beginning and recording the time at which each of them boiled.  I also recorded the temperature of the hot water and cold water in each of the ice cube trays and recorded the time at which they both started to freeze. I then also added salt to one cup and normal water to the other and recorded the beginning temperature and recorded the time at which they started to freeze.   The next step is to analyze and make conclusions based off the question you had, the hypothesis you made, and the experiment.  I analyzed by information by recording my findings and putting them into a graph to make it easier to read and show my results. 

 

My data and conclusions from my experiments were basically spot on to what I thought was going to happen, besides the experiment with the salt water.  I thought that the salt water would freeze faster which turned out to be not true.  I was thinking that maybe the salt would also the water to freeze at a faster rate.  In each experiment I boiled hot a cold water, froze hot and cold water, and froze salt water and normal water to see which would either boil faster or freeze faster.  After each experiment was done I looked at my dependent and independent variable.  Each time the temperature of the water was the independent variable and the time at which it either froze or boiled depended upon the temperature. 

 

These experiments each relate to real life because when cooking if you use the hot water it will boil faster than if you use cold water.  Also, it proved that when in the winter time when you put salt on ice, it allows it to melt faster which also explains why the water with salt in it froze at a slower rate because the salt slowed the freezing time.