The effect of increasing temperature on the solubility of two solids.

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The effect of increasing temperature on the solubility of two solids

Aim

Question :
What is the effect of increasing temperature on the solubility of
(a) a Salt
(b) a Sugar
when they are placed in
(1) Ethanol
(2) Water.

This is basically asking if solubility is proportional to the temperature of the solvent. The idea is to do it in ethanol and water with a salt and a sugar. This is to test the question in two different liquids (solvents) with two different solids (solutes) to reach a more accurate answer.

Predictions

Solubility is the number of grams of the solute that will dissolve in 100 g of the solvent. Some things may dissolve in water but not in other liquids and some things may dissolve in other liquids and not in water.

Water is a polar solvent. Polar solvents are liquids whose molecules display a permanent dipole. A dipole has two oppositely charged poles (like a magnet). A molecule with a dipole is a molecule with a positive and a negative end. Ionic compounds are compounds that will split into two or more ions when placed in a liquid. Ions are particles that are positively charged (cations) or negatively charged (anions). Ionising liquids (polar liquids capable of dissolving ionic compounds) will dissolve ionic compounds well because they can pull both anions (with the positive ends of the molecules) and cations off (with the negative ends of its molecules). Salts are ionic compounds so I would expect them both to dissolve well in water.

I am going to use sodium chloride (common or table salt) in my experiment.
e.g.

So when you heat a polar liquid (water) it should dissolve a greater quantity than at room temperature (22-25 degrees C). The liquid molecules have more energy to move around and break the chemical bonds between the sodium and the chloride ions in the compound. They do that by attracting an ion by the oppositely charged end of the dipole in the molecule.

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Because liquid molecules have more energy to break the chemical bonds between component particles in compounds, I would expect most compounds to dissolve better at high temperatures rather than low temperatures.

Ethanol is an organic compound and therefore is likely to be a covalent compound and unlikely to be a polar liquid. I do not expect ethanol to dissolve ionic compounds such as sodium chloride.

Most compounds should follow the general rule (a solute will dissolve better when the solvent is at a higher temperature rather than a low temperature). Sugars are not ionic compounds and therefore do not have ...

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