Experimental Procedures Flashcards
What is the process of evaporation?
Solvents can be removed from a solution using evaporation. The disadvantage of this sepearting method is that the solvent is not collected and is effectively lost. This process will not be appropriate for harmful or flammable solvents.
What is the process called filtration?
Filtration is used to separate an insoluble solid from a liquid. This technique is used to collect solid substance formed during a precipitation reaction.
How should you go about collecting gases from a reaction?
Collecting gas over water is used for insoluble gases (or gases with very limited solubility), Hydrocarbons, Hydrogen and Carbon dioxide can be collected in this way If the measurement of a volume is required then the use of a measuring cylinder is required.
Gas syringes can be used for both soluble and insoluble gases. It provides an accurate measurement of volume but there is a limit to the volume of gas that can be collected in this way.
What should you do in a titration process?
Titrations are used to prepare an exact volume of a solution, if the concentration of the solution is accurately known, the solution is called a standard solution.
Preparing the standard solution
- Dissolve the solute in the solvent (typically de-ionised water)
- Transfer solution to volumetric flask along with several rinsings from the beaker.
- make up mark with deionised water. A dropper can be used to add the final drops of the solvent
-Invert the volumetric flask to mix
Use a glass pipette to transfer an accurately know volume into the conical flask
Burette should be used to add liquid during the titration
-The burette must be rinsed using the solution that will be used in the titration
- Filter funnel should be added to the top of the burette to add the solution
- Record the initial volume of the solution measuring from the meniscus
- remove the filter funnel prior to commencing the titration
-Ensure that there is no air bubble in the space below the tap.
