- #1
sero2000
- 27
- 0
Hi I am just wondering why during precipitation, hydrochloric acid is added to the mixture of barium chloride and sodium sulphate. Does it have something to do with the PH values or what?
Borek said:There is a common contaminant (present in the air) that gives precipitate with Ba2+. Low pH will drive it away.
Borek
--
the ultimate buffer calculator
Borek said:Not all, only some, but your precipitate will be contaminated, thus it will not have known exact composition.
Also note, that if your solution contains other metals, in hight pH their hydroxides can preciptate, which won't happen in low pH. Finally, HSO4- is a relatively weak acid, in low pH it ismostly protonated, which slows down precipitation. That's good - the slower the precipitation, the larger the crystals are and the easier filtration is.
Somehow I feel presence of someone green and small...
Gravimetric analysis is a method used in analytical chemistry to determine the quantity of a substance present in a sample based on its weight. It involves isolating the substance of interest and measuring its weight, which can then be used to calculate the amount of the substance in the original sample.
In gravimetric analysis, a known volume of a sample is first obtained and then treated with a reagent to precipitate the substance being analyzed. The precipitate is then collected, dried, and weighed, and the weight is used to determine the amount of the substance in the sample.
Gravimetric analysis is a highly accurate method of analysis, as it relies on direct measurement of the substance of interest. It is also relatively simple and can be used to analyze both organic and inorganic substances.
Gravimetric analysis can be time-consuming and requires careful handling of samples to prevent contamination. It is also not suitable for analyzing substances that are volatile or easily decomposed.
Gravimetric analysis is commonly used in environmental testing, pharmaceutical analysis, and quality control in industries such as food and beverage, chemical, and mining. It is also used in research and development to determine the composition of unknown substances.