K2O

Formula : K2O

Family: 
Oxides
High temperature: 
Reacts violently with water producing potassium hydroxide [K(OH)].
Geological context: 
Potassium oxide or potash (formula K2O) is a compound of potassium and oxygen used mainly as a fertilizer. It is obtained from the combustion of plant material.

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
 V°
cm3·mol-1
 ΔGºf
J·mol-1
 ΔHºf
J·mol-1
 Sº
J·mol-1·k-1
 CP
J·mol-1·K-1
94.196 40.380 (Ref.: 95rob/hem) Robie R.A., and Hemingway B.S., 1995. Thermodynamic properties of minerals and related substances at 298.15 K and 1 Bar (105 Pascals) pressure and at higher temperatures. U.S. Geol. Survey Bull., 2131, 461 pp. -322086 (Ref.: Internal calculation) -363170 (Ref.: 98cha) Chase, M.W.J., 1998. NIST-JANAF Thermochemical Tables, Journal of Physical Chemistry Reference Data, Vol. 9, 4th Edition. National Institute of Standards and Technology, Washington DC, 1951 pp. 94.140 (Ref.: 98cha) Chase, M.W.J., 1998. NIST-JANAF Thermochemical Tables, Journal of Physical Chemistry Reference Data, Vol. 9, 4th Edition. National Institute of Standards and Technology, Washington DC, 1951 pp. 83.68 (Ref.: 98cha) Chase, M.W.J., 1998. NIST-JANAF Thermochemical Tables, Journal of Physical Chemistry Reference Data, Vol. 9, 4th Edition. National Institute of Standards and Technology, Washington DC, 1951 pp.
CP(T) = a + b·T + ·c·T-2 (T in Kelvin)
a
J·mol-1·K-1
 b * 103
J·mol-1·K-2
 c * 10-5
J·K·mol-1
 Maier Kelley Ref.
83.68 0.00 0.00 (Ref.: 98cha) Chase, M.W.J., 1998. NIST-JANAF Thermochemical Tables, Journal of Physical Chemistry Reference Data, Vol. 9, 4th Edition. National Institute of Standards and Technology, Washington DC, 1951 pp.
Reaction properties

K2O + 2H+ ⇌ 2K+ + H2O

298.15 K, 1 bar log10K: 84.11 ΔH°r:-426940 J·mol-1 (Ref.: 98cha) Chase, M.W.J., 1998. NIST-JANAF Thermochemical Tables, Journal of Physical Chemistry Reference Data, Vol. 9, 4th Edition. National Institute of Standards and Technology, Washington DC, 1951 pp.
T(°C) 0 25 60 100 150 200 250 300
log10K 90.95 84.11 76.25 69.10 62.07 56.54 52.06 48.35
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-150.569581 -0.021690 31266.668032 57.417117 -515732.379320