The aim of this experiment is to find the concentration of a sample of limewater solution in g dm?3. I am required to design my own experiment and choose a range of appropriate equipment and apparatus. The indicator will be supplied to me. I am provided with 250 cm3 of limewater, which has been made such that it contains approximately 1g dm?3 of calcium hydroxide. Also available is hydrochloric acid which has a concentration of 2.00 mol dm?3, this concentration is too much though so it is necessary to dilute it.
The apparatus, equipment and chemicals that I will use are as follows: -
1) Pipette 25cm3
2) Volumetric flask 500cm3
3) Conical flask 250cm3
5) White tile
6) Clamp and stand
7) Indicator (methyl orange)
8) Limewater (250cm3 with 1g dm?3 of calcium hydroxide)
9) Hydrochloric acid- standard solution (conc. 2.00 mol dm?3)
10) Distilled water
Slaked lime dissolved in water is called limewater.
Quicklime + Water ? Slaked lime
CaO(s) + H2O(l) ? Ca(OH)2(s)
Calcium oxide reacts violently with water to produce calcium hydroxide (slaked lime)
Addition of further water to Calcium hydroxide produces the saturated aqueous solution known as Limewater.
In the experiment it is necessary to react the Hydrochloric acid with the Limewater in order to establish the concentration of the limewater.
Acid + Metal Hydroxide ? Salt + Water
The balanced equation that takes place is:
Limewater + Hydrochloric acid ? Calcium chloride + Water + Hydrogen
Ca(OH)2(aq) + 2HCl ? CaCl2 + 2H2O
In order for the experiment to be accurate and reliable it will be necessary to dilute the Hydrochloric acid significantly. It is in my belief that a concentration of 0.1mol dm?3 would enable me to achieve reliable results. This would require a dilution factor of...