Prelim Prac, need help PLZ (2 Viewers)

[Unsure121]

hi,
I have to research and perform a first hand investigation to test the solubilities in water of a range of substances that include ionic (sodium chloride), soluble molecular (sucrose), insoluble molecular, covalent networks (silicon dioxide) and large molecules cellulose).

I have no idea what substances I should use in the experiment or what method/s i should use.

Anything would be greatly appreciated.

Oh and I need to hand in a materials list by wednesday

 

[Gussy Booo]

Hmmmmmmmmmm, I think it might be more then just testing the solubility of the substances in water. What substances should you use ? Does it really matter? You're meant to be testing that aren't you? Lol

However, I think when the substance dissolves in water, it will be either a exothermic or endothermic reaction. Therefore, you'll have to do some extra calculations concerning q = mc∆t .

I'm assuming this, because that's what we're doing in class too. Instead however, we're doing the Heat of Combustion, which is similar, just that we're measuring the amount of energy being released by a hydrocarbon.

Anyways, so lets take Sodium Chloride for example.

When you put the substance in water, it will react with water. This reaction will either adsorb surround heat (endothermic) making the beaker/cup cooler, or release heat (exothermic) making the beaker/cup hotter.

I think you're going to have to measure the differences in heat from the original to the last, and make some extra calculations concerning q = mc∆t .

OR

It could also be as you've said it. If that's the case, it's quite easy. Just put the substance in and make qualitative observation. This observation should revolve around assuming whether the result is soluble, soluble (exothermic), soluble (endothermic), slightly soluble, very soluble, insoluble and Immiscible.

I need this prac in my book. This was my conclusion:

Conclusion : Substances with hydrogen bonds will be soluble in water. The more hydrogen bonds, the great the solubility. If there are no hydrogen bonds present, other bonds such as dispersion bonds or/and dipole-dipole forces may be present, though they are easily broken.

Good luck.