Question #db5fb

1 Answer
Feb 15, 2017

Just looking at a formula it is difficult to determine – although the molecular mass may give some clues.


Additionally, to determine the phase state of a compound we need to know the conditions of temperature and pressure. Further, “aqueous” in the list usually refers to being in a water solution. A compound may or may not have much solubility in water, but that is a different consideration from the physical phase of the pure compound.

Using “Normal” temperature (20’C) and pressure (1 atm) #CO_2# is a gas, #H_2O# can be either liquid or gas, MgO, NaCl, #AlCl_3, KNO_3, PbI_2, CuCO_3# and Cu are all solids. All of them except elemental copper can be put into an aqueous solution.

At elevated pressure #CO_2# can become a liquid, and at very low temperature it becomes a solid, as does #H_2O#.