Finding the Concentration of Calcium Hydroxide by Titration with Hydrochloric Acid.

Finding the Concentration of Calcium Hydroxide by Titration with Hydrochloric Acid.

The Problem

Perform a titration upon Calcium Hydroxide to find the concentration

by using Hydrochloric Acid of 3 different concentrations as following

2 molar, 0.5 molar and 0.1 molar. In order to calculate the results

must be within 0.05cm3 of each other.

Apparatus

Burette

Volumetric Pipette

Beakers

Conical Flasks

Volumetric Flasks

Funnel

Clamp Stand

White Tile

Fair Test

For a fair test I will have to make sure that I change the equipment

for each test so that the residue of the last test doesn't alter my

results and also I must use the same amounts measured as accurately as

possible.

Preliminary Work

The first experiment will have will have to be a titration with the

given amounts of Hydrochloric Acid to see whereabouts my equilibrium

will lie. It is more accurate to have the results between 15cm3 and 30

cm3.

Method

Starting with one of the known concentrations measure out 25cm3 of it

for the titration using the volumetric pipette.

Assemble apparatus (as shown in diagram) after collecting goggles and

lab coat for safety.

Move your apparatus to eve level (i.e. to a stool) and pour the HCl in

till the meniscus rests on the 0 level exactly so that your results

can be measured accurately from the same marker every time.

Move the apparatus back onto the table, and measure 25cm3 of calcium

hydroxide accurately with the volumetric pipette (ensuring that it is

clean, washed with distilled water then the solution you are using)

and pour it into a conical flask.

Add a few drops of phenolphthalein indicator which will make the

solution pink and you can tell when the end point is near so make it

more accurate.

Turn on the tap from the burette and let the HCl run into the pink

Ca(OH)2. Shake the flask constantly to evenly distribute the HCl in