Question

Does the standard state refers to an element is its natural state at 1 atm pressure, 25^oC? Does the liquid metals (copper,iron etc.) will under their standard states if the pressure is 1 atm? What about a solute of 1 molarity but doen't in an atmosphere of 1 atm pressure, 25^oC? Thanks.

Answer 1

For a standard state of an element 1 atm or bar is necessary but the condition of 25°C or 298 K is not necessary or mandatory , this temperature correspond to room temperature so this temperature is of our interest only.

By definition , standard state is defined as purest state of an element at 1 bar (or approximately atm) and the temperature at which this element exist in it's pure form. Metal are generally solid, so liquid metals (copper,iron etc.) will be not under their standard states if the pressure is 1 atm.

Generally for solution standard state is 1 M at 1 bar ( or atm), but just 1 M can be also considered as standard state of element.