Mg determination Lab report
Mg2+ Determination using EDTA
Linh Nguyen
Chem 1212L – 165
Feb 08 , 2014
Purpose and Procedure:
The purpose of this experiment is using Compleximetric titration and EDTA to determine the concentration of Mg2+ in solution; and also calculating the percent by mass of MgO in the unknown sample. This procedure results no significant deviations.
The procedure for the experiment is from the lab manual referenced below Laboratory Experiments for Chem 1211L & 1212L (6e), with Contributions from Georgia Perimeter Faculty, Cengage Learning, Block/McKelvy. Page 153 to 158 (Experiment Title: “Determination of Mg+ using a Complexmetric Titration”)
Introduction:
In this experiment, EDTA (ethylenediaminetetraacetic acid) is use as a controlled chemical to determine the concentration of Mg2+. The reason why EDTA is used is because EDTA reaction has large equilibrium constants, so it is easy to measure. In basic solution, EDTA loses 4 protons to become the conjugate base commonly abbreviated asY4- as follows: Mg2+ + EDTA4- => MgEDTA2-
Our indicator in this experiment is EBT( Eriochrome Black T). When we add excess of EDTA to EBT-Mg2+ solution, the later will decompose and the EDTA-Mg2+ complex will form, and the solution changes from red to blue
Data
Data table for compleximetric titration of Mg2+ sample:
Volume used: 300 mL
Mass of Na2EDTA*2H2O
0.9565 g
Molar mass of Na2 EDTA*2H2O
372.25 g/mol
Expected M of EDTA solution
8.57 E-3 M
Standardization of EDTA Solution
Concentration of Zn2+: 0.010009M
Volume used: 10.00 mL
Trial 1
Trial 2
Trial 3
Final buret reading, EDTA
18.83 ml
37.20 ml
Initial buret reading, EDTA
0.00 ml
18.83 ml
Volume used, EDTA
18.83 ml
18.37 ml
Molarity of EDTA solution
5.312 E-3 mol/L
5.445 E-3 mol/L
Average molarity of EDTA solution:
5.379 E-3 mol/L
Determination of % MgO of Unknown:
Unknown Number: 2A
Sample Calculations:
Linh Nguyen
Chem 1212L – 165
Feb 08 , 2014
Purpose and Procedure:
The purpose of this experiment is using Compleximetric titration and EDTA to determine the concentration of Mg2+ in solution; and also calculating the percent by mass of MgO in the unknown sample. This procedure results no significant deviations.
The procedure for the experiment is from the lab manual referenced below Laboratory Experiments for Chem 1211L & 1212L (6e), with Contributions from Georgia Perimeter Faculty, Cengage Learning, Block/McKelvy. Page 153 to 158 (Experiment Title: “Determination of Mg+ using a Complexmetric Titration”)
Introduction:
In this experiment, EDTA (ethylenediaminetetraacetic acid) is use as a controlled chemical to determine the concentration of Mg2+. The reason why EDTA is used is because EDTA reaction has large equilibrium constants, so it is easy to measure. In basic solution, EDTA loses 4 protons to become the conjugate base commonly abbreviated asY4- as follows: Mg2+ + EDTA4- => MgEDTA2-
Our indicator in this experiment is EBT( Eriochrome Black T). When we add excess of EDTA to EBT-Mg2+ solution, the later will decompose and the EDTA-Mg2+ complex will form, and the solution changes from red to blue
Data
Data table for compleximetric titration of Mg2+ sample:
Volume used: 300 mL
Mass of Na2EDTA*2H2O
0.9565 g
Molar mass of Na2 EDTA*2H2O
372.25 g/mol
Expected M of EDTA solution
8.57 E-3 M
Standardization of EDTA Solution
Concentration of Zn2+: 0.010009M
Volume used: 10.00 mL
Trial 1
Trial 2
Trial 3
Final buret reading, EDTA
18.83 ml
37.20 ml
Initial buret reading, EDTA
0.00 ml
18.83 ml
Volume used, EDTA
18.83 ml
18.37 ml
Molarity of EDTA solution
5.312 E-3 mol/L
5.445 E-3 mol/L
Average molarity of EDTA solution:
5.379 E-3 mol/L
Determination of % MgO of Unknown:
Unknown Number: 2A
Sample Calculations: