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Salts & brines

Sodium sulfate · Na2SO4

Sodium sulfate (Na2SO4) is a salt; this page gives computed density and dynamic viscosity for aqueous solutions from 2–14 wt% and 20–60 °C.

Values are computed from the Laliberté (2009) aqueous-electrolyte correlation and tabulated over 214 wt% and 2060 °C.

Also known as
Salt cake, Glauber's salt (decahydrate), Disodium sulfate
CAS number
7757-82-6
Tabulated range
214 wt% · 2060 °C
Properties
Density · Dynamic viscosity · Specific gravity
At 12 wt% · 20 °C
reference snapshot
Density
1110.6kg/m³
Density
1.1106g/cm³
Specific gravity
1.113
Viscosity
1.524cP
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 214 wt% and 2060 °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 214 wt% and 2060 °C range.

8 wt%
20 °C
Density
1072.1 kg/m³
Density
1.0721 g/cm³
Specific gravity
1.074
Dynamic viscosity
1.300 cP
Density (kg/m³) vs wt% Na2SO4 at 20 °C — Sodium sulfate.
Why it matters

What the numbers tell you

At 12 wt% and 20 °C, aqueous sodium sulfate has a density of about 1111 kg/m³ (1.111 g/cm³) — roughly 1.11× the density of water. It also has a dynamic viscosity of about 1.524 cP, against roughly 1 cP for water at the same temperature. Those differences carry straight into volume-to-mass conversions, pump and pipe sizing.

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% Na2SO4°CDensity kg/m³SGViscosity cP
4201034.71.0371.131
8201072.11.0741.300
12201110.61.1131.524
14201130.21.1321.663
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 2-96 Sodium Sulfate density, from International Critical Tables, Vol. III, p. 81
  • CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions (viscosity at 20 degC)
  • Steiger, M. & Asmussen, S. (2008). Crystallization of sodium sulfate phases in porous materials: the phase diagram Na2SO4-H2O. Geochim. Cosmochim. Acta 72, 4291-4306. doi:10.1016/j.gca.2008.05.053 (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 / pointDensity · 12 wt% · 20 °C
Cited reference value1110.9 kg/m3
Model computed1110.56 kg/m3
Error vs reference0.031% (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 2-96 Sodium Sulfate (Na2SO4) (data from International Critical Tables, Vol. III, p. 81): 12 wt% Na2SO4 at 20 degC = 1.1109 g/cm3.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% Na2SO4). 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%2468101214
201016.31034.71053.31072.11091.21110.61130.2
251015.01033.21051.61070.31089.31108.51128.1
301013.41031.51049.81068.41087.21106.41125.9
351011.71029.61047.71066.21085.01104.11123.5
401009.71027.51045.61063.91082.71101.71121.1
451007.61025.21043.21061.51080.21099.21118.5
501005.31022.91040.81059.01077.61096.51115.8
551002.81020.31038.21056.31074.91093.81113.1
601000.31017.71035.41053.51072.01090.91110.2
Dynamic viscosity cP (mPa·s)
°C \ wt%2468101214
201.0631.1311.2091.3001.4041.5241.663
250.9441.0041.0731.1531.2441.3491.469
300.8450.8990.9611.0311.1111.2031.308
350.7620.8110.8660.9291.0011.0821.175
400.6920.7360.7860.8420.9070.9801.062
450.6320.6720.7170.7690.8270.8920.966
500.5800.6170.6580.7050.7580.8170.883
550.5350.5680.6070.6490.6980.7520.812
600.4950.5260.5620.6010.6450.6950.750
Typical values

Sodium sulfate solution properties at 25 °C

At 25 °C, 4 wt% sodium sulfate has a density of about 1033.2 kg/m³ and a dynamic viscosity of about 1.004 cP. At 25 °C, 12 wt% sodium sulfate has a density of about 1108.5 kg/m³ and a dynamic viscosity of about 1.349 cP. At 25 °C, 14 wt% sodium sulfate has a density of about 1128.1 kg/m³ and a dynamic viscosity of about 1.469 cP.

Limitations

Before you use these numbers

  • Laliberte (2009) aqueous-electrolyte correlation for Na2SO4-water, density and viscosity. Tabulated for 2-14 wt% over 20-60 degC. Sodium sulfate has an unusual solubility curve that collapses as it cools: stable saturation is only about 16 wt% Na2SO4 at 20 degC (as the decahydrate, Glauber's salt) and falls steeply below that, so the 20 degC floor and 14 wt% ceiling keep the whole table below saturation. Heat capacity is not tabulated: the correlation's Na2SO4 heat-capacity data begins at 25 degC, above this table's floor, so it is omitted rather than extrapolated. Concentrations are anhydrous Na2SO4; the decahydrate (Glauber's salt) is 44% Na2SO4 by mass. Values are for preliminary design; verify against vendor data for critical service.
  • Values are tabulated only inside the 214 wt% and 2060 °C ranges shown; the correlation is not extrapolated beyond them here.
  • Figures are for a pure sodium 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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