SUGAR AND SALT CRYSTALS IN DIFFERENT TEMPERATURES
Gracie M
2011-2012
ABSTRACT
The purpose of this experiment was to find out if different types of crystals grow
differently in different types of weather. The two different t types of crystals where sugar
crystals and salt crystals. Three of each type of crystals were made. To make each the
sugar crystals first a piece of string was tied to a pencil so that when put over top of the
beaker, the string would not touch the bottom or sides of the beaker. Next water was
heated on a hot plate and sugar was stirred into it. This mixture was then poured into a
beaker and the pencil with string was put inside, one sugar crystal was put into a
incubator, one in a refrigerator, and one in a room. This same process was also used to
make the salt crystals, except instead of sugar, salt was added. It was hypothesized
that the salt crystal in the refrigerator would grow the quickest and the best. It was
shocking to find that the complete opposite happened; the sugar crystal in the warm
temperature grew both the best and the quickest.
Sugar and Salt crystal in the refrigerator
INTRODUCTION
The purpose of this experiment was to see if temperature affected the growth of sugar
and salt crystals. Which type of crystal grows the quickest? Which type of crystal grows
the best? Some more questions that were asked where; what are sugar and salt
crystals? Why do they take the form of crystals? And what happens when sugar or salt
mixes with water?
When two elements combine they create something called compounds. Compounds
have more than one atom which are bound together to form molecules. When water and
salt mix together they create a compound and the molecules forms making the crystal.
When sugar and water mix together they also create a compound and the molecules
form also to the shape of a crystal. If only a little bit of salt or sugar is added to the
water, nothing will happen because the water will just dissolve the salt or sugar easily
and not enough of the ingredient will be used in order for the molecule to form. So it is
important that the water is over saturated. Although water can normally dissolve a little
bit of sugar or salt, it cannot dissolve infinite amounts. But the warmer temperature the
water is, the more sugar can be dissolved in it. Therefore the water must be very hot to
supersaturate the water. When as much sugar is dissolved in the water as possible, it is
said to be supersaturated.
The sugar and salt crystals grow better in temperatures that stay constant. So results
could vary if the crystals are put in a wavering temperature. Although with all the
different types of recipes this rule stays the same. There are many different recipes for
making sugar crystals, and every different recipe calls for different amounts of sugar or
salt dissolved in the water.
Although only sugar and salt is being used to form crystals in this experiment, there are
many different types of crystals that people can make. Some of these crystals are made
up of alum, halite, and lots more. But almost every salt (when mixed with water) can be
made into a crystal, and many different types of sugar can be made into crystals also.
Many observations where made out of the two ingredients; salt and sugar. The sugar
was kind of clear, and had a whitish tent to it, but when all the grains where together,
the sugar looked like a cream color. Each grain of sugar was a little square or diamond
shaped, and each grain of salt was very different. When the sugar was felt, it had a
sandy feeling to it. And when the sugar was shaken it made a very soft noise. Each
grain of salt also looked clear, but as the sugar, when the grains where in groups the
salt turned white, much whiter than the sugar actually. Each grain of salt was very round
and almost each grain of salt looked alike. When the salt was felt it also felt like sand,
and grainy.
The hypothesis for this experiment was that the sugar crystals would grow the quickest
in colder temperatures because, typically sugar is lighter than salt and it is hypothesized
that the sugar will be the quickest to form because of this. It is thought that the crystal
will grow the best in colder temperatures because the colder temperatures will help the
crystals become more steady and in place. It is thought that the room temperature
sugar crystals will grow the second quickest because it is the next coolest temperature.
However it is hypothesized that the sugar crystals growing in warmer temperatures will
not grow well because climate may make the crystal a little more soft and it may take
longer for the crystal to form. Although it is hypothesized that the sugar crystals will
grow the quickest, it is also hypothesized that the salt crystals will grow the best
because of the heaviness of the salt making the process slower, but steadier.
MATERIALS & METHOD
The materials that will be used for this experiment are:

Pencils

Yarn

Beakers

Sugar

Salt

Water

Hot plate

Goggles
Sugar and salt crystal in the incubator
A piece of yarn was tied to the middle of a pencil. Next, water was heated with a hot
plate at about 300 degrees and then the sugar was slowly stirred into it. Once the
sugar was dissolved, the mixture was quickly poured into a clear cup/jar. The pencil
with the string now attached was placed up at the top of the cup, so that the string is
hanging into the cup without touching the bottom or sides. This same experiment will
be done three different times. One of the non-grown crystals will be put into an
incubator, one will be put into a refrigerator, and one of the crystals will be put in a
room temperature. Next, water will be heated, once again although instead of sugar;
salt will be slowly stirred into the water. Once the salt was dissolved, the mixture was
also will be poured into a clear cup. The same pencil that was used with the sugar
crystals will also be put on the top of the cup. This experiment will be done three
different times. One of the crystals will be placed in an incubator, one of the salt
crystals will be put into a refrigerator, and one salt crystal will be put into a room
temperature. The control of this experiment is the sugar and salt crystal grown in
room temperature. The independent variable to this experiment would be the
temperature and the dependent variable to this experiment would be the speed that
the crystals grow. While heating the water up, be sure to wear goggles. The next
question that was asked was “can sugar crystals be grown in other liquids?” First a
piece of string was tied to the middle of a pencil so that the string can dangle in the
beaker without touching the bottom or the sides.100 mL of sprite was poured into a
beaker and put on a hot plate. The sprite was heated up and 2 more cups of sugar
was slowly added to it. Next the pencil with the string attached was put into the
beaker of sprite.
Results & DISCUSSION
Type of Crystal
Sugar 1
Salt 1
Sugar 2
Salt 2
Sugar 3
Salt 3
Temperature
Number of Days
room
room
cold
cold
warm
warm
0
1
0
0
0
1
On the first day after all of the crystals were made and placed in a room
temperature, a warm temperature, or a cold temperature, the salt crystal in the room
temperature immediately started to form. Along with the room temperature salt
crystal, the salt crystal in the incubator also grew rapidly, and it also grew just a little
bit larger that the salt crystal in room temperature. Although both the salt crystal in
the incubator and the salt crystal in room temperature started to grow quickly, the
salt crystal in the refrigerator had not grown at all. The sugar crystal in the room
temperature also did not grow at all, and in fact none of the sugar crystals had
grown. Over the next couple of days, not much happened to the crystals. The room
and warm temperature salt crystals had slowly developed a hard white crust around
the outside of the beakers. And slowly the sugar crystals in the incubator and the
sugar crystal in room temperature, started to form a goop around the string inside
the sugar water. The goop around the string had turned a little red at some parts of
the string, and it was a very odd substance. However the crystals that had been
growing ( the salt crystals in warm and room temperatures), did not get larger, the
only time they grew were around the first day. The red goop around the string in the
warm and room temperature sugar crystals started to get larger and started to get
even redder. Over the next couple of days, the salt crystals still did not get larger.
But the salt crystal in the room temperature seemed as if it started to grow outside
the water, the part of the string that was out of the water started forming a white
crust also, like the outside of the beaker. This did not happen to any of the other
crystals though. The sugar crystal growing in the sprite did not grow. After a couple
of days, the sugary sprite was still just a syrupy liquid.
Sugar crystal in room temperature
sugar and salt crystal in room temperature
CONCLUSION
As it turns out, the hypothesis was wrong. The hypothesis was that the sugar crystal
in the cold temperature would grow the quickest and the best, but instead the total
opposite happened; the salt crystal in the warm weather grew the biggest and the
best. It was thought that the sugar crystal in the cold temperature would grow the
quickest and the best because the chilly temperature would freeze the sugar in
place, but neither the sugar crystal nor the salt crystal grew in the refrigerator.
It is thought that the salt crystal was the type of crystal that grew the best because each
grain of salt is large and making it more stable than the sugar crystals. It is thought that
the salt crystal grew better in the warm temperature because the temperature helped
dissolve the rest of the salt into the water making the sugar crystal grow more efficiently.
It is thought that the sugar crystals did not grow in the soda because sugar crystals
must mix with water to be able to form, and the ingredients in the soda didn’t help the
sugar crystal to grow. It is thought that the sugar and salt crystals in the cold weather
didn’t grow because while the warm temperature helped the crystals to dissolve, the
cold temperature did the opposite; make the sugar just sink to the bottom. This
experiment could be improved if the measurements were more exact, and the amounts
were noted more carefully. In the future this experiment could be added on to if different
liquids where tested to see if sugar or salt crystals could grow in them, instead of just
testing sugar crystals in sprite.
REFRENCES
Administrator at sugar crystals.net. “Facts about Sugar Crystals”. “Sugar Crystals”. Dec.
16, 2010. Web. Jan. 24.
Holden, Alan. “Crystals and Crystal Growing”. Cambridge, Mass: MIT Press, 1982. Print
Symes, R. F. and Harding, R.R “Crystals and Gems”. London; New York: DK, 2000.
Print.