Title: gravimetric factor
Long Title: IUPAC Gold Book - gravimetric factor
DOI: 10.1351/goldbook.09044
Status: current

Definition
Mass fraction of analyte in a precipitate (see precipitation) obtained in a gravimetric analysis.

Notes
1) Gravimetric factor is calculated by \(g_{\rm{F}} = (M_{\rm{A}}v_{\rm{A}})/(M_{\rm{P}}v_{\rm{P}})\), where \(M_{\rm{A}}\), \(M_{\rm{P}}\) are molar masses of analyte and precipitate, respectively, and \(v_{\rm{A}}\) and \(v_{\rm{P}}\) are the stoichiometric numbers in the precipitation reaction.
2) Historically, the gravimetric factor is given the initialism GF, but to conform to the IUPAC convention that quantities should have a single symbol, it is recommended that \(g_{\rm{F}}\) is used in equations.
3) The gravimetric factor is used to calculate the mass fraction of an analyte in a sample (\(w\)) by \(w = m_{\rm{P}}/m_{\rm{sample}} \times g_{\rm{F}}\), where \(m_{\rm{P}}\) is the mass of precipitate and \(m_{\rm{sample}}\) the mass of sample.

Examples
1) Sulfur trioxide (\(M(\ce{SO3}) = \pu{80.0640 g mol-1}\)) is precipitated as barium sulfate (\(M(\ce{BaSO4}) = \pu{233.390 g mol-1}\)), \(\pu{1 mol}\) \(\ce{SO3}\) becomes \(\pu{1 mol}\) \(\ce{BaSO4}\). Therefore, \(g_{\rm{F}} = 80.0640/233.390 = 0.343048\).
2) Disilver oxide (\(M(\ce{Ag2O}) = \pu{231.736 g mol-1}\)) is dissolved and precipitated as silver chloride (\(M(\ce{AgCl}) = \pu{143.321 g mol-1}\)), \(\pu{1 mol}\) of \(\ce{Ag2O}\) becomes \(\pu{2 mol}\) \(\ce{AgCl}\). Therefore, \(g_{\rm{F}} = ½(231.736/143.321) = 0.808451\).

Related Term
- gravimetric analysis: https://goldbook.iupac.org//terms/view/09043

Source
- PAC, 2025, 97, 137. 'Glossary of terms for mass and volume in analytical chemistry (IUPAC Recommendations 2024)' on page 4 (https://doi.org/10.1515/pac-2023-0903)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/09044/html
- json: https://goldbook.iupac.org/terms/view/09044/json
- xml: https://goldbook.iupac.org/terms/view/09044/xml

Citation: Citation: 'gravimetric factor' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.09044
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Accessed: 2026-05-09T01:33:28+00:00