1. log a U pH ++++ 25°C Uraninite U UOH U(OH) 2 4 6 8 10 12 14 –16 –142 4 6 8 10 12 14
–16
–14
–12
–10 –8 –6 pH
log a U
++++ U
U(OH) ++ 3 + 5 -
UOH
+++
Uraninite
25°C
Log K = -3.5
Log K =

2. Use the “Alter log Ks” option to adjust the equilibrium constant for a reaction without permanently modifying a thermo dataset.

3. add → Mineral… → Uraninite
Config → Alter Log Ks…
Top row values are preserved in the dataset.
Temporarily adjust the reaction’s log K at any principal temperature, then click Apply.
add → Mineral… → Uraninite

4. The stability field for Uraninite has decreased.
Original diagram