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Do all substances dissolve? - Coggle Diagram
Do all substances dissolve?
What is a substance
Are all substances obtainable?
What substances should be used
No, due to safety,cost and other restrictions
Would be impossible/impractical to test 'all' substances
A chemical substance is a form of matter having constant composition and properties
What exactly is dissolving?
to cause a solute to pass into a solution
happens when the attraction between the particles of the solvent and solute are strong enough to overcome the attraction of the particles of the solute for one another.
Also known as dissolution
How will we measure if they dissolve?
Visually
Checking if the solute is visible in its original form
Factors Affecting solubility
Temperature
Higher energy in the moleculse4 allows the secondary forces to be broken easier
Solubility increases
Surface Area
The more surface area, the more area is available to react
Dissolution is faster
Polarity
Like Dissolves like principle
Nonpolar molecules
Non polar solutes dissolve non polar solvents
Non polar solutes dissolve in non polar solvents because both are held together by dispersion forces, so dispersion forces can form between the solute and solvents.
non polar substances do not dissolve in polar solvents because the polar molecules are held together by stronger hydrogen bonds, so the dispersion forces are not strong enough to overcome the strong force of attraction in the polar molecules
Ionic substances
Ionic compounds dissolve in polar solvents but not non-polar solvents, as when ionic substances dissolve, the ions seperate from the ionic lattice, forming an ion dipole bond in a polar molecule
Polar molecules
polar solutes generally dissolve in polar solvents
the solute and solvent are held together by dipole-dipole attractions, which can form between the solute and solvents
Polar solutes generally do not dissolve non polar solvents
polar solutes do not dissolve in non polar solvents because the solute molecules are held together by dipole dipole attractions, and the non polar solvent molecules are held together by dispersion forces, which are not strong enough to overcome the dipole dipole attractions
Molecular size
The larger the molecule, the more secondary interactions
Higher force to break the molecules apart from each other
Solubility decreases/ substance becomes insoluble
Solubility
the ability to be dissolved, especially in water.
What is saturation
the point at which a solution cannot dissolve any more of a substance
Factors affecting dissolving also affect solubility
supersaturation
when the concentration of a solute is above the saturation level in equilibrium
What is it measured in
Grams per ml of solution
How will this be tested
What Solvents should be used
limitations of a school lab
Some solvents cannot be used
too dangerous for school lab usage
unobtainable due to multiple other factors
Polar
Water
Methylated spirits
Ethanol
Ammonia solution
Non polar
Petrol
Kerosene
Benzene
Hexane
What Solutes should be used