Unit 7: Solutions

1. Unit 7: Solutions Properties of Solutions Presentation

3. Homogenous Solution/Mixture • Formed by a physical change • All solutions are homogenous mixtures • Uniform mixture of substances • Cannot tell that that it is a mixture of two or more substances (can’t see the parts) • Cannot separate by filtration • Must use other means • Designated as aqueous NaCl(aq)

5. Heterogeneous Mixture • NOT A SOLUTION!!!! • Physical blend of two or more substances • Clearly a mixture • You can see the parts • Can use filtration or other means to separate

7. 5 Characteristics of Solutions • 1. Homogeneous • 2. Clear (do not disperse light) • 3. Can have color (with a transition metal) • 4. Do not settle upon standing • 5. Will always pass through a filter

9. Solute Vs. Solvent • 1. Solute- substance that is dissolved when creating a solution • 2. Solvent- substance that does the dissolving when preparing a solution

10. Like Dissolves Like 3 conditions exist for solution formation • Ionic solute with polar solvent (water) • Polar solute with polar solvent (water) • Non-polar solute with non-polar solvent (acetone) • All other combinations will not work when creating a solution because of lack of particle attractions

12. Factors Affecting Solution Formation • 1. Type of solute/solvent (must be compatible) • 2. Temperature • High temperature favors dissolving of solids and liquids • Low temperature does not (not enough energy) • Gases will favor opposite conditions (low temperature is good but high is bad) 3. Agitation-stirring brings together solute and solvent

13. Continued 4. Particle Size: Small particles are better because this increases surface area 5. Concentration: Need to make sure that you have enough solvent 6. Pressure: GASES ONLY!!!!!!!!!!!!!!!!!!!!!! High pressure and low temperature makes gases most soluble Low pressure and high temperature makes gases not soluble