# Observed species

Observed species allow you to monitor the property of a particular species in a vessel.

To add an observed species to a vessel:

- Go to the Properties pane for the vessel.
- Open the Observed Chemical Properties section and press the '+' button.
- Type the formula of the species you wish to observe in the details box exactly as it appears in the ionic view of the Reaction details (e.g 'H2O(aq)' ).
- Choose a property of this species from the drop-down menu in the details box.
- You can now monitor this property in the vessel using a Presentation part.

Tips for use:

- For species that dissociate (e.g. 'HCl(aq)' ) bracket the first ion in the formula (e.g. '(H)Cl(aq)' ) to indicate the fully dissociated form of the species.
- For ionic species, put the charge after the chemical symbol, writing it as a number of '+' or '-' corresponding to the charge on the ion (e.g. 'SO3--(aq)' ).

## See also:

- Glassware