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Determining the solubility of
Sodium hydroxide !
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Yunha Kim!
Gyeonggi Suwon International School !
IB DP Chemistry SL!
Research Question!
How is the solubility of sodium hydroxide (NaOH) in water affected by temperature? !
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Introduction !
Sodium hydroxide is categorised as metal halide salt, composed of sodium and chlorine.!
The ions present in the solid crystals of potassium chloride dissolve and gain mobility in water.
When potassium chloride is dissolved in water, the following endothermic reaction occurs:!
NaOH(s) + H2O(l) → Na+(aq) + OH–(aq) + H2O(l)!
This reaction takes place because water is a polar solvent and display a permanent dipole status.
Therefore ionic compounds will break into two or more ions when dissolved in such solvent. The solubility of the compounds may be affected by different aspects that influence the energy of the molecules in the solvent. This experiment is specifically designed to measure the solubility of sodium hydroxide in waters of different temperatures.!
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Hypothesis!
Higher temperature of water allow the particles of sodium hydroxide(s) more mobility between the solution and their solid state because the particles are absorbing energy from their surrounding.
Therefore, higher the temperature of water, higher the solubility of sodium hydroxide. !
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Table of variables!
Variable measured
Dependent
Variable
Method of measuring
The solubility of
Sodium hydroxide
The mass of a 50ml beaker – Final mass of the 50ml beaker
Independent Temperature of water
Variable
The temperature will be manipulated using a heating plate and kept consistent at desired level using a thermometer
Variable controlled Method of controlling
Controlled
variables
• The volume of distilled water!
• The volume of solution extracted!
• The amount of
Sodium hydroxide!
• Mass of the 50ml beakers! • Syringe insertion point! • Time