Composition of calcium carbonate in egg shell
Chemistry IA
Aim: Calculate the percent composition of Calcium carbonate in egg shell
Equipment:
Pestel
Mortar
Conical flask
Egg shell
Measuring cylinder
Balance
Hydrochloric acid (1 mol/dm cube)
Sodium hydroxide (1 mol/ dm cube)
Pipette
Burette
Clamp
Beaker
Phenolphthalein
Safety:
Wear eye goggle during an experiment because of the strong hydrochloric acid
In case, if there is an acid contact your skin, quickly wash your skin with water
Pour acid on body level so it does not interact with you face
Independence variable:
Mass of egg shell: we can use different mass of egg shell to find our result
Dependence variable:
Purity of calcium carbonate in egg shell
Controlled variable:
Concentration of Hydrochloric acid
Uncertainty and error:
Measuring cylinder scale is plus minus 0.08 cm cube
Egg shell may have little bit of membrane which effect weight
Little bit of egg shell may not all dissolve
Our vision while pouring or recording data
Egg shell may contain some water
Collecting data
Take off egg shell and clean it with water
Take off egg membrane that attach in the inner shell
Dry it using tissue paper or dryer
Put it in mortar and slowly crush it with pastel
Weigh them with a balance a record it as gram
Pour egg shell into a conical flask
Add the amount of HCl (in the theoretical volume) to conical flask (Warning: slowly pour it because the reaction is rapid due to less surface area of egg shell)
Wait for the reaction to stop (a days)
Set up clamp which hold a burette
Now we have to titrate calcium carbonate with sodium hydroxide to find how many mole we have to use to neutralize
Before titrate pour 2 two drops of phenolphthalein on to calcium carbonate
Titrate until it look light pink
Titrate at least three times
Now use your record to calculate (see the calculation below)
When use back titration
Result of how much NaOH is used:
1st time
5.3 cm cube
2nd time
5.5 cm cube
3rd time
5.4 cm cube
Aim: Calculate the percent composition of Calcium carbonate in egg shell
Equipment:
Pestel
Mortar
Conical flask
Egg shell
Measuring cylinder
Balance
Hydrochloric acid (1 mol/dm cube)
Sodium hydroxide (1 mol/ dm cube)
Pipette
Burette
Clamp
Beaker
Phenolphthalein
Safety:
Wear eye goggle during an experiment because of the strong hydrochloric acid
In case, if there is an acid contact your skin, quickly wash your skin with water
Pour acid on body level so it does not interact with you face
Independence variable:
Mass of egg shell: we can use different mass of egg shell to find our result
Dependence variable:
Purity of calcium carbonate in egg shell
Controlled variable:
Concentration of Hydrochloric acid
Uncertainty and error:
Measuring cylinder scale is plus minus 0.08 cm cube
Egg shell may have little bit of membrane which effect weight
Little bit of egg shell may not all dissolve
Our vision while pouring or recording data
Egg shell may contain some water
Collecting data
Take off egg shell and clean it with water
Take off egg membrane that attach in the inner shell
Dry it using tissue paper or dryer
Put it in mortar and slowly crush it with pastel
Weigh them with a balance a record it as gram
Pour egg shell into a conical flask
Add the amount of HCl (in the theoretical volume) to conical flask (Warning: slowly pour it because the reaction is rapid due to less surface area of egg shell)
Wait for the reaction to stop (a days)
Set up clamp which hold a burette
Now we have to titrate calcium carbonate with sodium hydroxide to find how many mole we have to use to neutralize
Before titrate pour 2 two drops of phenolphthalein on to calcium carbonate
Titrate until it look light pink
Titrate at least three times
Now use your record to calculate (see the calculation below)
When use back titration
Result of how much NaOH is used:
1st time
5.3 cm cube
2nd time
5.5 cm cube
3rd time
5.4 cm cube