JoVE Logo

Oturum Aç

5.18 : Precipitate Formation and Particle Size Control

In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.

The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability increases with the size of the precipitate particles. Colloidal suspensions contain minuscule particles with diameters varying from 10−9 to 10−6 m, which are invisible to the naked eye and not easily filtered. However, crystalline suspensions have larger particles that settle quickly and are readily filtered.

The temperature, precipitate solubility, reactant concentrations, and speed of mixing of reactants can affect the particle size. The overall effect of these attributes is called relative supersaturation, RSS, which can be expressed in terms of the concentration of the solute (Q) and its equilibrium solubility (S). The size of the obtained particles is inversely proportional to the average relative supersaturation when the reagent is added. As a result, when the relative supersaturation ratio is high, colloidal precipitates are favored, while crystalline precipitates with large particle sizes are obtained at low relative supersaturation ratios.

Etiketler

Precipitate FormationParticle Size ControlPrecipitation GravimetrySpecific ReagentSelective ReagentPure SubstanceInsoluble PrecipitateFilterabilityColloidal SuspensionsCrystalline SuspensionsRelative SupersaturationRSSSolute ConcentrationEquilibrium Solubility

Bölümden 5:

article

Now Playing

5.18 : Precipitate Formation and Particle Size Control

Complexometric Titration, Precipitation Titration, and Gravimetry

703 Görüntüleme Sayısı

article

5.1 : Complexometric Titration: Overview

Complexometric Titration, Precipitation Titration, and Gravimetry

5.8K Görüntüleme Sayısı

article

5.2 : Complexometric Titration: Ligands

Complexometric Titration, Precipitation Titration, and Gravimetry

881 Görüntüleme Sayısı

article

5.3 : Properties of Organometallic Compounds

Complexometric Titration, Precipitation Titration, and Gravimetry

928 Görüntüleme Sayısı

article

5.4 : EDTA: Chemistry and Properties

Complexometric Titration, Precipitation Titration, and Gravimetry

1.7K Görüntüleme Sayısı

article

5.5 : EDTA: Conditional Formation Constant

Complexometric Titration, Precipitation Titration, and Gravimetry

709 Görüntüleme Sayısı

article

5.6 : EDTA: Auxiliary Complexing Reagents

Complexometric Titration, Precipitation Titration, and Gravimetry

532 Görüntüleme Sayısı

article

5.7 : EDTA: Direct, Back-, and Displacement Titration

Complexometric Titration, Precipitation Titration, and Gravimetry

2.3K Görüntüleme Sayısı

article

5.8 : EDTA: Indirect and Alkalimetric Titration

Complexometric Titration, Precipitation Titration, and Gravimetry

804 Görüntüleme Sayısı

article

5.9 : Complexometric EDTA Titration Curves

Complexometric Titration, Precipitation Titration, and Gravimetry

759 Görüntüleme Sayısı

article

5.10 : Effects of EDTA on End-Point Detection Methods

Complexometric Titration, Precipitation Titration, and Gravimetry

241 Görüntüleme Sayısı

article

5.11 : Masking and Demasking Agents

Complexometric Titration, Precipitation Titration, and Gravimetry

2.3K Görüntüleme Sayısı

article

5.12 : Precipitation Titration: Overview

Complexometric Titration, Precipitation Titration, and Gravimetry

5.4K Görüntüleme Sayısı

article

5.13 : Precipitation Titration Curve: Analysis

Complexometric Titration, Precipitation Titration, and Gravimetry

1.0K Görüntüleme Sayısı

article

5.14 : Precipitation Titration: Endpoint Detection Methods

Complexometric Titration, Precipitation Titration, and Gravimetry

1.6K Görüntüleme Sayısı

See More

JoVE Logo

Gizlilik

Kullanım Şartları

İlkeler

Araştırma

Eğitim

JoVE Hakkında

Telif Hakkı © 2020 MyJove Corporation. Tüm hakları saklıdır