Gravimetria por volatilizacion.pptx

Grabimetry

1. Gravimetry by volatilization Valentina Joselyne Chavez Bermudez

2. What is gravimetry ? Gravimetric analysis is a type of laboratory technique used to determine the mass or concentration of a substance by measuring a change in mass. The chemical we are trying to quantify is usually called the analyte. Gravimetric analysis can yield results of high accuracy (ideally, but it is a lengthy procedure that requires a lot of attention, so it is not advantageous if many samples are to be analyzed. Isn’t advantageous if many samples are to be analyzed. Errors in the method are due to: L osses due to the solubility of the precipitate M echanical losses G ains due to co-precipitation

3. what is volatilization gravimetry ? Volatilization gravimetry involves separating the components of our mixture by heating or through chemical decomposition. This causes any volatile compounds to separate, resulting in a change in mass that we can measure.

4. It consists of measuring the components of the sample that are or may be volatile, it can only be used if the analyte is the only volatile substance and use is made of a selective absorbent or if the analyte is evaporated and the corresponding measurements are made on the residue obtained. It is based on a change of physical state to separate the compounds, for example: -Moisture expulsion - Ebulling to remove O2 and CO2 -Simple and fractional distillation. This method can also include volatile treatments or reagents to obtain volatile compounds.

5. Gravimetric equipment analytical balance desiccator

6. The analyte is volatilized at a suitable temperature. The volatile product is collected and weighed, or, the mass of the product is determined indirectly by mass loss in the sample. The mass of the product is determined indirectly by the loss of mass in the sample. Types of volatilization methods a ) The one applied for water: water is quantitatively removed from many inorganic samples by drying. In the direct direct determination, it is collected in any of the various desiccant solids and its mass is determined from the mass gained by the desiccant. Mass gained by the desiccant. In the indirect method the amount of water is determined by the loss of mass of the sample during heating. b ) Applied for CO2 : like the direct analysis for water, the mass of CO2 is determined by the increase in the mass of an absorbent solid. In the mass of an absorbent solid How is the volatilization of an analyte obtained?

7. EXAMPLE Examples include the expulsion of moisture to dry a sample, the calcination of a residue to remove ammonium salts, the boiling of a solution to remove dissolved oxygen, carbon dioxide, etc.

8. Direct method Occurs if we evaporate the analyte and pass it through an absorbent substance that has been previously weighed so that the weight gain corresponds to the analyte sought. Indirect method It is given if we volatilize the analyte and weigh the residue after volatilization so the weight loss suffered corresponds to the analyte that has been volatilized.

9. The calculations associated with gravimetric methods of analysis are based on stoichiometry and the results are determined from Mass of the sample. Mass of the product (or analyte) of known composition. The concentration of the product is expressed in percent of analyte .

10. Determination of the sodium bicarbonate hydrogen content in antacid tablets by indirect volatilization of carbon dioxide. The question is: could CO2 be volatilized and the content of sodium hydrogen bicarbonate in the antacid tablets be determined by indirect volatilization treated with dilute sulfuric acid in a solution, where NaHCO3(ac) + H2SO4(ac)  CO2 (g) + H2O(l) + NaHSO4(ac) EXAMPLE

11. This will only be possible if the reaction containing sulfuric acid and bicarbonate is carried out in a flask initially connected to a tube containing sulfate. Bicarbonate is carried out in a flask initially connected to a tube containing calcium sulfate (CaSO4) to obtain pure carbon dioxide (CO2) in nitrogen, one has (CaSO4) to get pure carbon dioxide (CO2) in nitrogen, the H2O vapor has to be removed from the initial reaction . H2O vapor has to be removed from the initial reaction. That is, these gases pass through the drying tube containing CaSO4. Drying tube containing CaSO4 ( Driedite ). Then, these gases are absorbed by an absorption tube (NaOH on a non-fibrous silicate ( Ascarbide ). silicate ( Ascarite )) containing the previously weighed adsorbent Ascarite II, where carbon dioxide is retained, producing the reaction. CO2 + 2 NaOH Na2CO3 + H2O In conclusion , the gravimetric procedure for volatilization of the products carbon dioxide (CO2) and water (H2O) is collected on heavy sorbents. The mass mass is used as the analytical variable.

12. VIDEO https://youtu.be/GAWyleVEVO0

13. Bibliographic references . Romero Bonilla, Í., & Dávila Dávila , K. (2015). Principios básicos de Química analítica cualitativa: para estudiantes de Ingeniería Química . https://www.docsity.com/es/gravimetria-por-la-volatilizacion/2494659/ Martínez, D. V. (2019, April). Efectos del QuitoMax y el Bayfolan Forte en el cultivo de la habichuela (Vigna unguiculata ). In 9na Edición de la Conferencia Científica Internacional de la Universidad de Holguín https://es.slideshare.net/Claudia-Lizeth/volatilizacion DE, A. L. F. Y. P. (2012). Facultad de Estudios Superiores Cuautitlán (Doctoral dissertation , UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO). https://prezi.com/9kyjt6gyjm4y/gravimetria-por-volatilizacion/?fallback=1

14. RUBRIC That's a huge number!