Salts & brines

Iron(II) sulfate · FeSO4

Name: Iron(II) sulfate (FeSO4) aqueous solution properties
Creator: ProcessConvert
License: https://creativecommons.org/licenses/by/4.0/

Iron(II) sulfate (FeSO4) is a salt; this page gives computed density, dynamic viscosity and specific heat capacity for aqueous solutions from 2–16 wt% and 15–25 °C.

Values are computed from the Laliberté (2009) aqueous-electrolyte correlation and tabulated over 2–16 wt% and 15–25 °C.

Also known as: Ferrous sulfate, Copperas, Green vitriol
CAS number: 7720-78-7
Tabulated range: 2–16 wt% · 15–25 °C
Properties: Density · Dynamic viscosity · Specific heat capacity · Specific gravity

At 12 wt% · 20 °C

reference snapshot

Density: 1124.9kg/m³
Density: 1.1249g/cm³
Specific gravity: 1.127
Viscosity: 1.529cP
Specific heat: 3627J/kg·K

Explore

Read a value at any point

Move the sliders to interpolate between the tabulated grid points. The readout and chart never go outside the validated 2–16 wt% and 15–25 °C range, and every number is interpolated from the committed table below — nothing is computed from a chemistry model in your browser.

Interactive explorer

Values are interpolated between the tabulated grid points below — sliders stay within the validated 2–16 wt% and 15–25 °C range.

Concentration9 wt%

Temperature20 °C

Density: 1091.3 kg/m³
Density: 1.0913 g/cm³
Specific gravity: 1.093
Dynamic viscosity: 1.343 cP
Specific heat: 3733 J/kg·K

Density (kg/m³) vs wt% FeSO4 at 20 °C — Iron(II) sulfate.

Why it matters

What the numbers tell you

At 12 wt% and 20 °C, aqueous iron(II) sulfate has a density of about 1125 kg/m³ (1.125 g/cm³) — roughly 1.13× the density of water. It also has a dynamic viscosity of about 1.529 cP, against roughly 1 cP for water at the same temperature, and a specific heat of about 3.63 kJ/kg·K, about 87% of water’s 4.18 kJ/kg·K. Those differences carry straight into volume-to-mass conversions, pump and pipe sizing, and the heat needed to change its temperature.

Common grades

A few working strengths

Properties at 20 °C for a handful of concentrations in everyday use, read from the committed grid (interpolated between tabulated points where a grade falls between them). The full table follows below.

wt% FeSO4	°C	Density kg/m³	SG	Viscosity cP	Sp. heat J/kg·K
4	20	1038.0	1.040	1.093	3942
8	20	1080.3	1.082	1.284	3770
12	20	1124.9	1.127	1.529	3627
16	20	1171.8	1.174	1.829	3497

Sources

Where the numbers come from

Every value on this page is computed by a deterministic model — none is entered by hand. The generating method and the references it is checked against:

▸Laliberte, M. (2009). A Model for Calculating the Heat Capacity of Aqueous Solutions, with Updated Density and Viscosity Data. J. Chem. Eng. Data 54(6), 1725-1760. doi:10.1021/je8008123
▸Perry's Chemical Engineers' Handbook, 7th ed. (Perry & Green) - Table 2-54 Ferrous Sulfate, from International Critical Tables, Vol. III (1928)
▸CRC Handbook of Chemistry and Physics - Aqueous Solubility of Inorganic Compounds at Various Temperatures (solubility bounds for the tabulated range)

Model: thermo==0.4.0 (chemicals==1.3.0) - Laliberte 2009 electrolyte correlation · Generated 2026-06-07

The committed data file for this page is published as JSON on GitHub under CC BY 4.0.

Validation

Checked against a cited value

The model is cross-checked at one independently cited reference point. The page is published only because this check passes.

Property / point	Density · 12 wt% · 18 °C
Cited reference value	1122 kg/m3
Model computed	1124.25 kg/m3
Error vs reference	0.2% (tolerance 1%)

Perry's Chemical Engineers' Handbook, 7th ed. (from International Critical Tables). Perry, R.H. & Green, D.W. (eds.), Perry's Chemical Engineers' Handbook, 7th ed., Table 2-54 Ferrous Sulfate (FeSO4) (data from International Critical Tables, Vol. III, p. 68): 12 wt% FeSO4 at 18 degC = 1.1220 g/cm3, anhydrous-salt basis. The 18 degC basis is the source table's reference temperature; the check is evaluated at 18 degC, inside the tabulated range.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% FeSO4). Read the cell at the intersection. Specific gravity is density divided by the model water reference of 998.2 kg/m³ at 20 °C.

Density — kg/m³

°C \ wt%	2	4	6	8	10	12	14	16
15	1018.4	1038.3	1058.7	1079.6	1101.1	1123.1	1145.5	1168.2
20	1017.8	1038.0	1058.8	1080.3	1102.3	1124.9	1148.1	1171.8
25	1016.9	1037.4	1058.6	1080.5	1103.0	1126.3	1150.2	1174.7

Dynamic viscosity — cP (mPa·s)

°C \ wt%	2	4	6	8	10	12	14	16
15	1.172	1.239	1.335	1.454	1.587	1.733	1.894	2.080
20	1.034	1.093	1.179	1.284	1.402	1.529	1.669	1.829
25	0.920	0.974	1.051	1.144	1.249	1.361	1.483	1.622

Specific heat capacity — J/kg·K

°C \ wt%	2	4	6	8	10	12	14	16
15	4063	3959	3870	3789	3715	3644	3576	3510
20	4050	3942	3850	3770	3696	3627	3561	3497
25	4036	3922	3829	3749	3676	3609	3545	3482

Typical values

Iron(II) sulfate solution properties at 25 °C

At 25 °C, 4 wt% iron(II) sulfate has a density of about 1037.4 kg/m³, a dynamic viscosity of about 0.974 cP and a specific heat capacity of about 3922 J/kg·K. At 25 °C, 12 wt% iron(II) sulfate has a density of about 1126.3 kg/m³, a dynamic viscosity of about 1.361 cP and a specific heat capacity of about 3609 J/kg·K. At 25 °C, 16 wt% iron(II) sulfate has a density of about 1174.7 kg/m³, a dynamic viscosity of about 1.622 cP and a specific heat capacity of about 3482 J/kg·K.

Limitations

Before you use these numbers

▸Laliberte (2009) aqueous-electrolyte correlation for FeSO4-water. Tabulated for 2-16 wt% over 15-25 degC only: the published density data behind the correlation for FeSO4 covers just that temperature window, so values are deliberately not tabulated beyond it. Saturation is about 19 wt% FeSO4 at 15 degC. Concentrations are anhydrous FeSO4; the heptahydrate (copperas, FeSO4.7H2O) is 55% FeSO4 by mass. Ferrous solutions oxidise in air, so stored liquors drift in composition. Values are for preliminary design; verify against vendor data for critical service.
▸Values are tabulated only inside the 2–16 wt% and 15–25 °C ranges shown; the correlation is not extrapolated beyond them here.
▸Figures are for a pure iron(II) sulfate–water system. Commercial grades contain impurities (for example chloride in some caustic grades) that shift density and viscosity; check the supplier's data sheet for a specific product.
▸Use for preliminary design; verify for critical service.

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