Lights Of Heaven - AppStartingBlogger Tricks

1. Introduction

1. Introduction

1.1 Background Research
Research was done to find out if impurities affected the boiling and freezing point of water. As shown in sci-experiment.com, it stated that if you added salt into pure water, its freezing point becomes lower.This is what happens when you add salt to water: Adding salt, or anything other than water, disrupts the equilibrium.

The salt molecules dissolve in the water, but do not attach easily to the solid ice. There are fewer water molecules in the liquid because some of the water has been replaced by salt. This means that the number of water molecules able to be captured by the ice (frozen) goes down, so the rate of freezing goes down. The rate of melting of the ice is unchanged by the presence of the salt, so melting is now occurring faster than freezing. as ice melts, energy is extracted from the surrounding liquid, and the liquid cools. And it continues to cool until the system returns to equilibrium, where the number of molecules of water that are freezing is equal to the number of ice molecules that are melting. Eventually, the temperature falls sufficiently to make the water molecules slow down enough so that more can attach themselves to the ice. When the number of water molecules that are freezing equals the number of ice molecules that are melting, equilibrium will be reached again. The higher the concentration of salt, the lower the temperature of the new freezing/melting point. As ice begins to freeze out of the salt water, the fraction of water in the solution becomes even lower, and the freezing point drops further!  (Khan Academy,2011)

However, this doesn't continue indefinitely. At some point the solution will become saturated with salt. This happens for salt in water at -21.1°C, which therefore is the coldest a saturated solution of salt and water can get. At that temperature, the salt begins to crystallize out of solution, along with the ice, until the solution completely freezes. The frozen solution is a mixture of separate salt (NaCl·2H2O) crystals and ice crystals. This heterogeneous mixture is called a eutectic mixture.
Any foreign substance added to the water will cause a freezing point drop. For every mole of foreign particles dissolved in a kilogram of water, the freezing point goes down by roughly 1.8°C. Sugar, alcohol, or any chemical salt will also lower the freezing point and melt ice. Salt is used on roads and walkways because it is inexpensive and readily available.
Adding salt does not lower the boiling point of water. 
Actually, the opposite is true. Adding salt to water results in a phenomenon called boiling point elevation. The boiling point of water is increased slightly, but not enough that you would notice the temperature difference. You would have to add 58 grams of salt just to raise the boiling point of a litre of water by one half of degree celsius. 


Our group also researched on the effects on the melting point and boiling point of water. Apparently , it is the same effect, but a bit less effective.

The aim of the research
Our aim is to find out if impurities like sugar and salt and the volume of the impurities can affect temperature when the water is boiling or melting.

1.2 Research Questions
Research Questions
1. How do we determine the boiling point of water containing impurities?
2. How do we determine the freezing point of water containing impurities?
3. Does salt affect the boiling or freezing point of water and ice?
4. Does sugar affect the boiling point or freezing point of water and ice?
5. Does amount of impurities matter when its affecting the boiling or freezing point of water and ice?
6. Is the amount of impurities added to the water proportional to the freezing and boiling point of water and ice?
7. If it affect the boiling point and freezing points, why?

1.3 Hypothesis
Hypothesis
The water's boiling point will be increased by 1 degree when 10 grams of salt was added to it. The salt solution's boiling point will be increased by 3 degrees when 30 grams of salt is added into the solution. The boiling point of the salt solution will be increased to 105 degrees when 50 grams of salt is added in.
The water's boiling point will be increased by 0.5 degrees when 10 grams of sugar is added to it. The sugar solution's boiling point will be increased by 1.5 degrees when 30 grams of sugar is added to it. the sugar solution's boiling point will be increased by 2.5 degrees when 50 grams of sugar is added to it.


Independent Variables
The amount of impurities added
Dependent Variables
Time taken for the water to boil
Temperature of solution
Constants
Type of water
Liquid Nitrogen
Type of Impurity









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