The purpose of this experiment is to find the solubility of salt in water at various temperatures. Key results from this experiment are the temperatures at which the crystals start forming, letting us know that the salt has dissolved, and therefore telling us the solubility of the salt. We know, from comparing our results to the expected results, that we made a few major errors in our calculations involving the temperature at which the crystals started to form. Regardless, we concluded that the solubility of salt is not a stable figure, but varies depending on the amount of water, the amount of salt added, and the temperature of the water.
The purpose of this lab is to determine the solubility of how much a salt can dissolve in water, of KCIO3 (potassium chlorate). In particular this lab will be determining the solubility at different temperatures. The water molecules are arranged in a hexagonal shape. All of the oxygen atoms have a negative charge, point towards the hydrogen atoms of other water molecules, having a positive charge. When the KCl hits the water, the K+ and Cl- ions dissociate. These ions will now be attracted to the appropriate opposite charges on the water and "fit in" between the water molecules with the charges all aligned, causing the potassium chlorate to dissolve. Materials and Methods
Large test tube and clamp
10-mL graduated cylinder
110 °C thermometer
4.5-5.0 g potassium chlorate
Assemble the apparatus. A 20 cm test tube is used with the thermometer as your apparatus then attached to a ring stand with a clamp. 4.5-5 grams of salt was weighed on a balance, then the exact mass was recorded on a data sheet. A graduated cylinder was then used to measure out 10 mL of water, and then added to the salt in the apparatus. The mass of the water added was recorded to the data sheet. The apparatus was then clamped to the ring stand, and...
References: Stanley Smith, S. (2000). Solubility. Retrieved from http://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text11/Tx112/tx112.html
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