Ice cube under influence
of MgCl and CaCl
Shumaila Mohammed & Khadija Elhamdi
Pieter Nieuwland College – The Netherlands
Summary
April 2011
With our research we tried to find out how fast a ice cube melts under influence of magnesium
chloride and calcium chloride compared with distilled water.
Our research shows that salting the slow melting process. This is because of the specific weight.
The specific weight of salt is higher than the melt water of the ice cube. This way the cold water hangs
around the ice cube. Also there is a decrease in the temperature while the ice cube melts.
If you add salt to melting ice, the temperature declines and increase the leven of the liquid.
When the ice cube melts the water consumes the released volume of the ice cube, causing the
increasing of the level of the liquid
Introduction
O
ur research question is: How fast does a
ice cube melt under influence of
magnesium chloride and calcium
chloride compared with distilled water?
Our hypothesis is that there will be a little
difference between magnesium chloride and
calcium chloride, because of the fact that they
are both salts. But compared with distilled water
the ice will melt faster in distilled water
than in the two salts, magnesium chloride
and calciumchloride. Saltwater has a lower freez
ing point than water without
added salt. The cold melt water is heavier than
the original water so it sinks to the
bottom. The warm water rises, which in
turn will melt ice. In short, circulation
occurs in the glass. The hot water makes the ice
melting faster. In the measuring cup with salt
water it goes otherwise The melt water
of the ice cube is sweet there and the
ambient water is salty. Distilled water is
much lighter than salt water. The cold
distilled water will not drop and the ice cube
remains surrounded by the cold melt
water. There is no convection and therefore the
ice in the glass with the
salt water melt much more slowly.
Experimental Procedure and
approach
For this project we needed different things, like
measuremt cups, stopwatch, ice cubes,
Magnesium chloride, calcium chloride and
distilled water. First we had to know how many
mol we need of MgCl2 and CaCl2. Solving one
mol of MgCl2 gives two parts and solving one
mol of CaCl2 gives three parts. We started with
Magnesium chloride. We took 20,0 gram of
Magnesium chloride and 0,5 litre water. The
molar mass of Magnesium chloride is 203,34.
That means that we had 20,0 / 203,34 = 9,8 x
10-1 mol of Magnesium chloride. Which is a
morality of 9,8 x 10-1. We need the same
morality of Calcium chloride. The molar mass
of Calcium chloride is 147,04 and amount mol
is 9,8 x 10-1. That means we need a mass of 9,8
x 10-1 x 147,04 = 14,46 gram of Calcium
chloride.
After we know how many grams we need, we
start our research. We melt three ice cubes in
three different measuring cups. In the first one,
there is Magnesium chloride, second one is
filled with Calcium chloride and the last one is
filled with distilled water. During the melting
we pay not only attention at the speed but also
on the size of the ice cubes, temperature and
level of the liquid. Furthermore, we keep the
temperature of the environment similar in all
the three proofs. After that we will try to give a
conclusion and explanation for the speed of the
melting of an ice cube in magnesium chloride
and in Calcium chloride compared with
distilled water.
Data gathering and analysis
As a team we came together at our college to
prepare and do our project. We were trying to
be very careful with the time. We checked the
ice cubes when we saw a difference in the
volume. We checked all the three ice cubes at
the same time. Further we used a thermometer
to check the temperature.
Results
Temperature
Time
(minutes)
0
3
12
13
Magnesium
chloride
19,0 ºC
18,0 ºC
17,9 ºC
17,9 ºC
Calcium
chloride
21,0 ºC
20,5 ºC
17,9 ºC
17,9 ºC
Distilled
water
20,0 ºC
18,0 ºC
18,0 ºC
18,0 ºC
Table 1: If you add salt to melting ice, the
temperature declines.
Volume ice cube
Time
(minutes)
0
3
12
13
Magnesium
chloride
11,0 ml
1,0 ml
-
Calcium
chloride
11,0 ml
2,0 ml
0,1 ml
-
Distilled
water
11,0 ml
-
Table 2: The specific weight of distilled water
is lower than the specific weight of melt
water. This decreases the
water that just melted faster
in distilled water and new water
of higher temperature can get to the ice cube.
Level of liquid
Time
(minutes)
0
Magnesium
chloride
500,0 ml
3
510,0 ml
12
510,0 ml
13
511,0 ml
Calcium
chloride
500,0
ml
509,0
ml
510,9
ml
511,0
ml
Distilled
water
500,0
ml
511,0 ml
511,0 ml
511,0 ml
Conclusion and discussion
Table 3: When the ice cube melts the water
consumes the released volume of the ice cube,
causing the increasing of the level of the liquid
*
- ; means that there is no change compared with the
previous observations
From our research is to note that an ice
cube melts the fastest in distilled water. At
number two is to stand magnesium chloride an
d calcium chloride, finally. This has to do with
the specific weight. The specific weight of
distilled water is lower than the specific
weight of melt water. This decreases the
water that just melted faster
in distilled water and new water
of higher temperature can get to the ice cube.
This speeds up the process of melting. This
also explains the distribution of the melt water.
This is not the case with salts. The specific
weight of salt is higher than the melt water of
the ice cube. This way the cold water hangs
around the ice cube. The reason why the
temperatures changes is because if you add
salt to melting ice, the temperature
declines. The freezing point of salt water is
less so salt water freezes slower but because
ice is frozen already in this case the
temperature drops to freezing / melting
point of salt water. And why the liquid level
increases is because, when the ice cube melts
the water consumes the released volume
of the ice cube, causing the increasing of the
level of the liquid.
Bibliography
1. Klaver, N. Chemical teacher at Pieter
Nieuwland College - Amsterdam
2. Bart, C. Chemical teacher at Pieter
Nieuwland College - Amsterdam
3.http://www.natuurkunde.nl/vraagbaak/vi
ew.do?request.requestId=11577