Making a salt with an alkali
To produce a salt when reacting an Corrosive substance which has a pH lower than 7. Acidity is caused by a high concentration of hydrogen ions. with an A base which is soluble in water., the method of A quantitative procedure in which two solutions react in a known ratio, so if the concentration of one solution is known and the volumes of both are measured, the concentration of the other solution can be determined. is used. This will produce a soluble salt.
Materials
The apparatus needed includes:
- a pipette to accurately measure a certain The volume of a three-dimensional shape is a measure of the amount of space or capacity it occupies, eg an average can of fizzy drink has a volume of 330 ml. of acid or alkali
- a pipette filler to use the pipette safely
- a conical flask to contain the liquid from the pipette
- a burette to add small, measured volumes of one reactant to the other reactant in the conical flask
Apparatus needed to carry out a titration
Method
This is an outline method for carrying out a titration in which an acid is added to an alkali.
- Use the pipette and pipette filler to add 25 cm3 of alkali to a clean conical flask.
- Add a few drops of A substance that has different colours, depending upon the pH of the solution it is in. and put the conical flask on a white tile.
- Fill the burette with acid and note the starting volume.
- Slowly add the acid from the burette to the alkali in the conical flask, swirling to mix.
- Stop adding the acid when the end-point is reached (the appropriate colour change in the indicator happens). Note the final volume reading.
- Repeat steps one to five using the same volume of acid from the burette without using an indicator. The resulting solution can then be evaporated to obtain pure crystals of the salt.
The same method works for adding an alkali to an acid 鈥 just swap around the liquids that go into the conical flask and burette.