Lexicographer
Retired 13 May 2006
Just a small slice of my lab report
Method
Phase
Using 50mL and 25mL pipettes, solutions were prepared as below in four labelled 250mL conical flasks. The masses of Ca(OH)2 are approximate.
1) 0.5g Ca(OH)2 + 100mL H2O
2) 0.5g Ca(OH)2 + 75mL 0.025M NaOH
3) 0.5g Ca(OH)2 + 50mL 0.050M NaOH
4) 0.5g Ca(OH)2 + 50mL 0.060M NaOH
The above flasks were individually warmed above a Bunsen on low flame whilst swirled for two minutes. They were then allowed to stand for five minutes, after which time they were stoppered and left to equilibrate for one hour. Throughout this hour the flasks were gently swirled several times.
Phase
75mL approximately 1.00M HCl was collected in a clean, dry 100mL beaker. From this sample 50.00mL was extracted by pipette to a 500mL volumetric flask, and made up to a 1:10 dilution with deionised H2O. The resultant solution was approximately 0.10M HCl.
1.3544g anhydrous Na2CO3 was collected in a specimen tube and weighed according to standard balance procedure. This sample was transferred to a 250mL beaker and dissolved in approximately 100mL H2O, then gently heated and stirred over a Bunsen on low flame until no solid specimen remained. The completely dissolved Na2CO3 solution was made up to 250mL in a volumetric flask with deionised H2O.
25mL aliquots of standard Na2CO3 were prepared in four conical flasks, to which were added three drops of methyl orange indicator. A 50mL burette was rinsed and filled with the approximately 0.10M HCl solution, which was then titrated against the four conical flasks of standard Na2CO3.
Phase
After the one hour cooling period had lapsed, the temperature of the four Ca(OH)2 solution flasks was measured. The cooled solution in each flask was then filtered by gently pouring into a Buchner funnel fitted with two sheets of № 42 filter paper and applying vacuum for ten minutes.
To the resulting filtrate was added three drops of phenolphthalein indicator. Each flask was then titrated directly against the previously standardised HCl solution.
Method
Phase
Using 50mL and 25mL pipettes, solutions were prepared as below in four labelled 250mL conical flasks. The masses of Ca(OH)2 are approximate.
1) 0.5g Ca(OH)2 + 100mL H2O
2) 0.5g Ca(OH)2 + 75mL 0.025M NaOH
3) 0.5g Ca(OH)2 + 50mL 0.050M NaOH
4) 0.5g Ca(OH)2 + 50mL 0.060M NaOH
The above flasks were individually warmed above a Bunsen on low flame whilst swirled for two minutes. They were then allowed to stand for five minutes, after which time they were stoppered and left to equilibrate for one hour. Throughout this hour the flasks were gently swirled several times.
Phase
75mL approximately 1.00M HCl was collected in a clean, dry 100mL beaker. From this sample 50.00mL was extracted by pipette to a 500mL volumetric flask, and made up to a 1:10 dilution with deionised H2O. The resultant solution was approximately 0.10M HCl.
1.3544g anhydrous Na2CO3 was collected in a specimen tube and weighed according to standard balance procedure. This sample was transferred to a 250mL beaker and dissolved in approximately 100mL H2O, then gently heated and stirred over a Bunsen on low flame until no solid specimen remained. The completely dissolved Na2CO3 solution was made up to 250mL in a volumetric flask with deionised H2O.
25mL aliquots of standard Na2CO3 were prepared in four conical flasks, to which were added three drops of methyl orange indicator. A 50mL burette was rinsed and filled with the approximately 0.10M HCl solution, which was then titrated against the four conical flasks of standard Na2CO3.
Phase
After the one hour cooling period had lapsed, the temperature of the four Ca(OH)2 solution flasks was measured. The cooled solution in each flask was then filtered by gently pouring into a Buchner funnel fitted with two sheets of № 42 filter paper and applying vacuum for ten minutes.
To the resulting filtrate was added three drops of phenolphthalein indicator. Each flask was then titrated directly against the previously standardised HCl solution.