substances' physical state

Question

in a chemical equation if a compound state is not given how am i supposed to determine it?i know the solubility rules but what about solid, liquid, and gas states?

Answer 1

If not given, in chemistry the phase of the substance is assumed to be the “standard” state. These you just have to have learned, memorized, or look up.

Answer 2

If you know the temperature of the reaction, you can check reference material for melting point and boiling point to determine if it will be a liquid - if the temperature is above the melting point or a gas - if the temperature is above the boiling point.

If you don't know the temperature of the reaction or for some reason the reaction causes a great increase in the temperature, this should give you clues about whether to say a state change has occurred.

Also, some classes of reactions will liberate gases, form precipitates, or cause the product to sublime.

Does this help?

Send me a message if you want me to try to come up with more ideas or help you more :)

Thanks,

John B.

Atlanta, GA

Former Chemist / Chemistry Teacher / Chemistry Tutor