Which of the following is NOT true about the thermodynamic standard state?

A. A pure liquid is in its standard state at 25C and a vapor pressure of 1.00 atm.

B. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C .

C. A solid is in its standard state when the atmospheric pressure is 1.00 atm and the temperature is 25C .

D. An aqueous solution is in its standard state at a concentration of 1.00 M.

E. All of these are true.

http://en.wikipedia.org/wiki/Standard_state

so which one is correct beacause both a,b, c are at 1 atm and 25 degrees

Have you misread the question? The question asks for which is NOT true. Your response of "so which one is correct because both a,b,c are at 1 atm and 25 dgrees?" is not true, either.

To determine which statement is NOT true about the thermodynamic standard state, we need to carefully analyze each option given.

A. A pure liquid is in its standard state at 25C and a vapor pressure of 1.00 atm.

This statement is true according to the definition of the standard state. A pure liquid is considered to be at its standard state when it is at a specific temperature and the vapor pressure is 1.00 atm.

B. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C.

This statement is also true according to the definition of the standard state. A gas is considered to be at its standard state when its pressure is 1.00 atm and its temperature is 25C.

C. A solid is in its standard state when the atmospheric pressure is 1.00 atm and the temperature is 25C.

This statement is true as well, as solids are typically considered to be at their standard state when the temperature is 25C and the atmospheric pressure is 1.00 atm.

D. An aqueous solution is in its standard state at a concentration of 1.00 M.

This statement is NOT true. The standard state for an aqueous solution is actually defined as a concentration of 1.00 M. So, D is the correct answer.

Therefore, the answer is D. An aqueous solution is NOT in its standard state at a concentration of 1.00 M.