Solutions

Solutions

1. Definition: A liquid that contains two or more components.

2. Examples: (solid/liquid) copper and zinc, (gas/liquid) fizzy drinks carbon dioxide and water.

3. Characteristics of solutions

   • The concentration is the amount of solute per volume of solution.
     • Concentration of solute (mol dm-3) x volume of solution (dm-3)
     • The amount of a liquid is express through its concentration.
     • Units: Units: (mol/dm-3) (g/dm-3)
   • Types of solutions
     • Stock solutions are more concentrated starting solution
       • A stock solution + solvent: Dilution
     • Standard solutions are solutions of known concentration has been standardized
   • Components
     • Solvent: Greatest quantity in a solution.
     • Solute: The solute is the component that is added to the solvent it has a lower quantity in solution.

4. Methods to calculate specific elements in solutions

   • Volumetric analysis
     • A method in which the concentration of a solution can be determined.
   • Titration
     • A technique to determine the reacting volumes in a precise way.
       • • Pipette is an instrument used to measure a known volume of one of the solutions into a conical flask.
         • Burette is a calibrated glass tube that can deliver precise volumes into the conical flask through opening the tap at the bottom.
         • The indicator determines the equivalence point in a solution, also it changes color at its endpoint. There are different types of indicators, it depends on the specific titration.
         • The equivalence point is the point in a titration where the amount of titrant added is enough to completely neutralize the analyte solution.

5. Units

   • Number of moles per solute: n:cV
   • PPM
     • A unit that is really useful to describe very low concentrations.
     • PPM: (mass of components/total mass solution) x 10^6
     • These values are based on mass and they are independent of temperature.
     • Parts per million (1 part per 10^6)

Images and files in the map

• Volumetric Analysis (Embed)
• Setting up and Performing a Titration (Embed)