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Coolants & brines

Potassium carbonate · K2CO3

Potassium carbonate (K2CO3) is a brine salt; this page gives computed density, dynamic viscosity and specific heat capacity for aqueous solutions from 5–35 wt% and -25–40 °C.

Values are computed from CoolProp's incompressible aqueous-mixture correlation (Melinder, 2010) and tabulated over 535 wt% and -2540 °C.

Also known as
Potash, Pearl ash, Dipotassium carbonate
CAS number
584-08-7
Tabulated range
535 wt% · -2540 °C
Properties
Density · Dynamic viscosity · Specific heat capacity · Specific gravity
At 20 wt% · 20 °C
reference snapshot
Density
1190.3kg/m³
Density
1.1903g/cm³
Specific gravity
1.192
Viscosity
1.714cP
Specific heat
3309J/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 535 wt% and -2540 °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 535 wt% and -2540 °C range.

20 wt%
20 °C
Density
1190.3 kg/m³
Density
1.1903 g/cm³
Specific gravity
1.192
Dynamic viscosity
1.714 cP
Specific heat
3309 J/kg·K
Density (kg/m³) vs wt% K2CO3 at 20 °C — Potassium carbonate.
Why it matters

What the numbers tell you

At 20 wt% and 20 °C, aqueous potassium carbonate has a density of about 1190 kg/m³ (1.190 g/cm³) — roughly 1.19× the density of water. It also has a dynamic viscosity of about 1.714 cP, against roughly 1 cP for water at the same temperature, and a specific heat of about 3.31 kJ/kg·K, about 79% 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% K2CO3°CDensity kg/m³SGViscosity cPSp. heat J/kg·K
10201090.91.0931.2683695
20201190.31.1921.7143309
30201298.61.3012.5502959
35201355.71.3583.2732824
Freezing point

How low it protects

Freezing point of the aqueous solution against strength, computed from the same correlation and checked against an independently cited value. A 35 wt% potassium carbonate solution freezes at about −26.7 °C.

wt% K2CO3Freezing point °C
5−1.6
10−3.6
15−5.9
20−8.8
25−12.8
30−18.6
35−26.7

Freeze check: 20 wt% computed −8.8 °C against a cited −8.8 °C (tolerance ±1.5 °C). CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions. CRC Handbook of Chemistry and Physics, Concentrative Properties of Aqueous Solutions, Potassium carbonate (K2CO3) table: 20.0 mass % at 20 degC, freezing point depression = 8.82 degC (freezing point about -8.8 degC). The CRC freezing-point-depression column agrees with the Melinder freeze curve underlying CoolProp's INCOMP::MKC to within 0.1 degC here.

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:

  • Melinder, A. (2010). Properties of Secondary Working Fluids for Indirect Systems, 2nd ed. International Institute of Refrigeration - the basis of CoolProp's incompressible aqueous potassium carbonate (INCOMP::MKC) correlation.
  • CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions (density, freezing-point depression and viscosity at 20 degC)

Model: CoolProp==6.6.0 - incompressible aqueous MKC correlation (Melinder 2010) · 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 · 20 wt% · 20 °C
Cited reference value1189.8 kg/m3
Model computed1190.32 kg/m3
Error vs reference0.044% (tolerance 1%)

CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions. CRC Handbook of Chemistry and Physics, Concentrative Properties of Aqueous Solutions (all data at 20 degC), Potassium carbonate (K2CO3) table: 20.0 mass % at 20 degC = 1.1898 g/cm3. This measured handbook data is independent of the Melinder correlation underlying CoolProp's INCOMP::MKC.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% K2CO3). Read the cell at the intersection. Specific gravity is density divided by the model water reference of 998.2 kg/m³ at 20 °C.

Cells left blank (—) sit below the solution's freezing point at that strength, where it is no longer liquid; those points are not tabulated and the explorer will not interpolate across them.

Density kg/m³
°C \ wt%5101520253035
-251373.4
-201372.3
-151312.61370.9
-101254.91311.21369.3
-51147.41199.41253.51309.61367.5
01048.21096.51146.31198.01251.81307.71365.4
51047.61095.51144.91196.31250.01305.71363.2
101046.71094.21143.31194.51247.91303.51360.8
151045.51092.61141.51192.51245.71301.11358.3
201044.11090.91139.51190.31243.41298.61355.7
251042.51089.01137.41188.01240.91296.01353.0
301040.71086.91135.11185.61238.31293.31350.3
351038.81084.81132.81183.11235.71290.51347.4
401036.91082.71130.41180.51232.91287.71344.6
Dynamic viscosity cP (mPa·s)
°C \ wt%5101520253035
-2515.66
-2012.28
-157.1379.831
-104.6185.9038.029
-52.8133.2453.9104.9676.676
01.9432.1422.4102.7913.3614.2455.643
51.6621.8482.0932.4332.9283.6774.839
101.4401.6141.8402.1452.5803.2244.203
151.2621.4241.6331.9102.2962.8553.692
201.1171.2681.4621.7142.0592.5503.273
250.9971.1381.3181.5481.8582.2922.924
300.8961.0271.1931.4051.6842.0712.628
350.8090.9311.0851.2781.5301.8762.372
400.7350.8460.9871.1631.3911.7022.146
Specific heat capacity J/kg·K
°C \ wt%5101520253035
-252746
-202754
-1529032762
-10307929112770
-534573270308629182779
03886366034663278309429262788
53890366834753286310129342797
103894367734843294310929422806
153899368634933301311629502815
203905369535013309312329592824
253912370435103316313129672834
303919371235183323313829762844
353926372135253330314529852854
403933372935323337315329942864
Typical values

Potassium carbonate solution properties at 25 °C

At 25 °C, 10 wt% potassium carbonate has a density of about 1089.0 kg/m³, a dynamic viscosity of about 1.138 cP and a specific heat capacity of about 3704 J/kg·K. At 25 °C, 30 wt% potassium carbonate has a density of about 1296.0 kg/m³, a dynamic viscosity of about 2.292 cP and a specific heat capacity of about 2967 J/kg·K. At 25 °C, 35 wt% potassium carbonate has a density of about 1353.0 kg/m³, a dynamic viscosity of about 2.924 cP and a specific heat capacity of about 2834 J/kg·K.

Limitations

Before you use these numbers

  • CoolProp's incompressible aqueous potassium carbonate correlation (INCOMP::MKC), built on Melinder (2010). Tabulated for 5-35 wt% K2CO3 over -25 to 40 degC. Potassium carbonate brine is a low-corrosion secondary coolant; the Melinder incompressible path is used (over the Laliberte electrolyte correlation) because it carries the freezing line needed for sub-zero service. Each cell sits above the solution's freezing line; cells below it are left blank and the explorer will not interpolate across them. The 35 wt% ceiling stays below saturation (about 53 wt% at 20 degC). Concentrations are anhydrous K2CO3. Values are for preliminary design; verify against vendor data for critical service.
  • Values are tabulated only inside the 535 wt% and -2540 °C ranges shown; the correlation is not extrapolated beyond them here.
  • Figures are for a pure potassium carbonate–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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