Solutions Solutions Homogeneous mixtures Solvent the substance there
Solutions
Solutions � Homogeneous mixtures � Solvent – the substance there is more of; it does the dissolving. � Solute – the substance there is less of; it is being dissolved. �Solute is dissolved in solvent
� Solvated – when the solute is surrounded by solvent molecules. � Hydrated – when the solute is surrounded by solvent molecules AND the solvent is water. � Is dissolving a chemical or physical change? ◦ Physical
Liquid vs. Aqueous � Na. Cl(l) ◦ Requires extremely high temperature to attain ◦ This is a solid that has melted � Na. Cl(aq) ◦ Dissolved in H 2 O ◦ Solid Na. Cl that has been dissolved in water ◦ Dissociation of ions �Doesn’t change the properties of the atoms �No chemical change
� Are ◦ No all things soluble? � Polar solvents dissolve polar solutes. ◦ Ex: water (polar) � Non polar solvents dissolve non polar solutes. ◦ Ex: oil (non polar) �“Like Dissolves Like”
Water � Known as “universal solvent” � The attraction between the H+ and O 2 - is a strong intermolecular force called an H-bond + -O H H H O H
Factors Determining Solubility � Intermolecular Forces � Temperature � Pressure ◦ For gases � What states of matter are required to form solutions? ◦ Any: solid, liquid or gas
Solute Solvent Gas Liquid Solid
How do you increase rate of dissolving? � Heating � Stirring � Crushing � One exception: gases dissolve better in colder temperatures.
Henry’s Law � Solubility of gas increases with pressure
� Solubility – the amount of solute that will dissolve in a given amount of solvent at a given temperature. � Saturated Solution – solution that contains all the solute it can at a given temperature. � Unsaturated Solution – solution that contains less than the saturated amount of solute. � Supersaturated Solution – solution that contains more solute than it could normally hold.
Solubility Curves � Every compound has its own solubility curve. � Typically, when heated, solubility will increase
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