EXPERIMENT 4:
QUANTITATIVE DETERMINATION OF SULPHATE BY GRAVIMETRIC ANALYSIS
FORMAL REPORT
NAME: CHIA KOK SIONG
ADMIN NO: 1027325
CLASS: DFST/FT/2B/21
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SYNOPSIS
The objective of this experiment is to determine the amount of sulphate by gravimetric analysis. The amount of sulphate is determined quantitatively as barium sulphate, BaSO4, by gravimetric analysis. For the experiment, a dilute solution of barium chloride was slowly added to a hot unknown sulphate solution slightly acidified with concentrated HCl. The precipitate is then filtered off by suction filtration, washed with water and dried in the oven at 150 degree Celsius for about half an hour and cooled in the desiccator, and weighed as barium sulphate and the percentage of sulphate was calculated from the weight of barium sulphate. The Molarity of sulphate= 0.004269 M and the concentration of sulphate in g/L= 0.4098g/L. The weight of barium sulphate was calculated to be 0.0249g. There were also no hiccups during the experiment.
(133 words)
OBJECTIVE
To determine the amount of sulphate by gravimetric analysis.
Students can also be familiar to the ways to carry out Gravimetric Analysis through this experiment.
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THEORY
Gravimetric analysis has become one of the most accurate classes of analytical methods available. Commonly, gravimetric analysis is being carried out by the following steps: (1) preparing a solution containing a known weight, (2) isolation of the desired elements, (3) weighing the separated elements and (4) computation of the amount of constituent in the sample from the observed weight of the isolated substance. Precipitation and filtration are the most commonly used methods to isolate the desired substances from a solution. The reagents used in the reactions will form an insoluble compound with the desired constituents but not precipitate of other elements.
Firstly, exactly 25mL of given sulphate solution was used so that it would be
References: Dr.Nutts (2010) Definition of Gravimetric Analysis [online] Available from : http://www.chm.davidson.edu/ronutt/che115/viii_gravi.pdf - INFORMATION FOR GRAVIMETRIC ANALYSIS (THEORY SECTION) http://www.dartmouth.edu/~chemlab/techniques/vfiltration.html - INFORMATION ON SUCTION FILTRATION (THEORY SECTION) http://www.laboratoryequipmentworld.com/filtering-flasks.html- THE USE OF A FILTER FLASK (THEORY SECTION) http://en.wikipedia.org/wiki/Gravimetric_analysis - COMPARING RESULTS AND PROCEDURES WITH INTERNET SOURCES (DISCUSSION SECTION)