percentage of calcium carbonate in egg shell
To determine the percentage by mass of Calcium carbonate in an egg shell
Aim: is to find and work out the percentage of calcium carbonate by mass in eggshells by using acid base “back titration” Introduction:
Calcium Carbonate, CaCO₃, is a compound which is polymorphic and therefore means that it can be found in a variety of different objects or organisms. For example: Rocks (limestone,calcite), sea snail shells, Eggshells, pearls and many more.
This investigation will focus on finding out the percentage mass of calcium carbonate in a given amount of egg shell, it can also be used to determine the calcium carbonate in limestone rock or sea shells and also help people sell the right eggs.
In this investigation a process called “back titration” will be used to find the concentration of a reactant by reacting it with an excess amount of another reactant.
In this case an unknown volume of calcium carbonate in egg shells reacts with an excess of hydrochloric acid so that it is sure that a reaction is occurring. The excess HCl is then diluted because of the egg shell with a drop of phenolphthalein added and is then titrated in aliquots with sodium hydroxide solution.
This is the reaction for determining the excess of HCl:
2HCl (aq) + CaCO3(s) -→ Ca2+ (aq) + CO2(g) + H2O(l) + 2Cl- (aq)
Materials:
eggshell burette, 50 cm³, and stand pipette + filler, 20 cm³ plastic foil phenolphthalein indicator
0.1 M NaOH solution,
M hydrochloric acid,
Distilled water forceps safety eye wear
2 beakers, 100 cm3 volumetric flask, 250 cm3 filter funnel
Mortar and pestle
Method
The shell of an egg must be removed and washed with soap to remove any organic matter. It must then be dried in an oven and then grinded into small pieces
All the glass ware apparatuses must be rinsed before being used
The egg shell pieces must be put on a scale and accurately weighed to 6.000 g. and later put into a conical flasks.
About 20.0cm³ of 1.0 mol dm ̄³HCl was poured
Aim: is to find and work out the percentage of calcium carbonate by mass in eggshells by using acid base “back titration” Introduction:
Calcium Carbonate, CaCO₃, is a compound which is polymorphic and therefore means that it can be found in a variety of different objects or organisms. For example: Rocks (limestone,calcite), sea snail shells, Eggshells, pearls and many more.
This investigation will focus on finding out the percentage mass of calcium carbonate in a given amount of egg shell, it can also be used to determine the calcium carbonate in limestone rock or sea shells and also help people sell the right eggs.
In this investigation a process called “back titration” will be used to find the concentration of a reactant by reacting it with an excess amount of another reactant.
In this case an unknown volume of calcium carbonate in egg shells reacts with an excess of hydrochloric acid so that it is sure that a reaction is occurring. The excess HCl is then diluted because of the egg shell with a drop of phenolphthalein added and is then titrated in aliquots with sodium hydroxide solution.
This is the reaction for determining the excess of HCl:
2HCl (aq) + CaCO3(s) -→ Ca2+ (aq) + CO2(g) + H2O(l) + 2Cl- (aq)
Materials:
eggshell burette, 50 cm³, and stand pipette + filler, 20 cm³ plastic foil phenolphthalein indicator
0.1 M NaOH solution,
M hydrochloric acid,
Distilled water forceps safety eye wear
2 beakers, 100 cm3 volumetric flask, 250 cm3 filter funnel
Mortar and pestle
Method
The shell of an egg must be removed and washed with soap to remove any organic matter. It must then be dried in an oven and then grinded into small pieces
All the glass ware apparatuses must be rinsed before being used
The egg shell pieces must be put on a scale and accurately weighed to 6.000 g. and later put into a conical flasks.
About 20.0cm³ of 1.0 mol dm ̄³HCl was poured