Experiment 1
Name: Sanzhar Kerimbek 20140930
General Chemistry Laboratory 1 Fall Semester 2014
Co-worker: Byungsoo Kim 20140831
Date: 27.09.2014
Title:Volumetric analysis
Introduction
The concept of volumetric analysis is a part of chemical analysis and is performed foremost with the volumetric chemical glassware (i.e. Erlenmeyer flasks, burets, pipets, test tubes etc.). The aim is to find out the concentration of one substance by reacting it in aqueous solution with the substance with known-concentration and then determining the unknown concentration.
There are two ways to get the standardized solutions: A primary standard – is a precisely measured on a balance and therefore moles of a solid substance dissolved in a water. Then it …show more content…
Also, we used acidic indicator phenolphthalein to determine the end point of experiment when the color turns from colorless into red or pink.
Potassium acid phthalate is our primary standard and this huge molecule has molecular mass equal to 204.2 g/mol. (KHC_8 H_4 O_4 ) and it has abbreviation as KHP. Also KHP is monoprotic and will react in a simple one to one ratio:
NaOH(aq) + KHC_8 H_4 O_4 (aq) →KNaC_8 H_4 O_4 (aq) + H_2O(l)
The ionic equation is:
Na^+ (aq) + OH^- (aq) + K^+ (aq) + HC_8 H_4 O_4 〖^-〗(aq) →Na^+ (aq) + K^+ (aq) + H2O(l) + C_8 H_4 O_4 〖^(2-)〗(aq)
In this titration endpoint will not coincide with the equivalence point because at the equivalence point the color of the solution will be colorless and we cannot observe the endpoint, so, excessive drop of the base will color the solution to the pink and we consider it as the end point.
The next titration with standard solution of NaOH with unknown concentration of HCl. The procedure is like previous titration of KHP with NaOH, but in this case instead of acid KHP we use hydrochloric acid. The HCl will react in one-to-one ratio with the base, so it will be easy to calculate the concentrations. The reactions follow:
HCl (aq) + NaOH (aq) → H_2O(l) + NaCl
Name: Sanzhar Kerimbek 20140930
General Chemistry Laboratory 1 Fall Semester 2014
Co-worker: Byungsoo Kim 20140831
Date: 27.09.2014
Title:Volumetric analysis
Introduction
The concept of volumetric analysis is a part of chemical analysis and is performed foremost with the volumetric chemical glassware (i.e. Erlenmeyer flasks, burets, pipets, test tubes etc.). The aim is to find out the concentration of one substance by reacting it in aqueous solution with the substance with known-concentration and then determining the unknown concentration.
There are two ways to get the standardized solutions: A primary standard – is a precisely measured on a balance and therefore moles of a solid substance dissolved in a water. Then it …show more content…
Also, we used acidic indicator phenolphthalein to determine the end point of experiment when the color turns from colorless into red or pink.
Potassium acid phthalate is our primary standard and this huge molecule has molecular mass equal to 204.2 g/mol. (KHC_8 H_4 O_4 ) and it has abbreviation as KHP. Also KHP is monoprotic and will react in a simple one to one ratio:
NaOH(aq) + KHC_8 H_4 O_4 (aq) →KNaC_8 H_4 O_4 (aq) + H_2O(l)
The ionic equation is:
Na^+ (aq) + OH^- (aq) + K^+ (aq) + HC_8 H_4 O_4 〖^-〗(aq) →Na^+ (aq) + K^+ (aq) + H2O(l) + C_8 H_4 O_4 〖^(2-)〗(aq)
In this titration endpoint will not coincide with the equivalence point because at the equivalence point the color of the solution will be colorless and we cannot observe the endpoint, so, excessive drop of the base will color the solution to the pink and we consider it as the end point.
The next titration with standard solution of NaOH with unknown concentration of HCl. The procedure is like previous titration of KHP with NaOH, but in this case instead of acid KHP we use hydrochloric acid. The HCl will react in one-to-one ratio with the base, so it will be easy to calculate the concentrations. The reactions follow:
HCl (aq) + NaOH (aq) → H_2O(l) + NaCl