Quantity (mol kg^-1)

name

formula

[CO₂](aq)

c₀

k₀ * pCO₂ / 1000000

total alkalinity

talk

constant derived from measurements, see section 5.10

[H⁺] first approxⁿ

h1

[k₁*c₀+(k₁²*c₀² + 8* k₁*k₂*c₀* talk)^0.5] / (2*talk)

[OH^-] first approxⁿ

oh1

k_w / h1

total phosphate

tp

constant, derived from weight added, see above

total borate

tb

constant, 0.000416, see above

[H₃PO₄]

p₀

tp* h1³ / ( h1³ +kp₁ * h1² + kp₁*kp₂ *h1 + kp₁*kp₂*kp₃)

[H₂PO₄]^-

p₁

p₀ * kp₁ / h1

[HPO₄]^2-

p₂

p₁ * kp₂ / h1

[PO₄]^3-

p₃

p₂ * kp₃ / h1

[B(OH)₃]

b₀

tb * h1 / (h1 + kb)

[B(OH)₄]^-

b₁

b₀ * kb / h1

carbonate alkalinity

calk

talk - b₁- p₂ - 2*p₃ - oh1 + h1 + p₀

[H⁺]

h

[k₁*c₀+(k₁²*c₀² + 8* k₁*k₂*c₀* calk)^0.5] / (2* calk)

pH (unitless)

ph

- log₁₀(h)

[HCO₃^-]

c₁

c₀ * k₁ / h

[CO₃^2-]

c₂

c₁ * k₂ / h

[OH^-]

oh

k_w / h

TCO₂

tCO₂

c₀ + c₁ + c₂