Which one of the following statements about standard states is incorrect?

a. The standard state of an aqueous solute is a saturated solution in water.

b. The standard state of a solid compound is the pure solid.

c. The standard state of a gaseous compound is the gas at a pressure of 1 atmosphere

d. The standard state of a liquid compound is the pure liquid.

This is incorrect:

The standard state of an aqueous solute is a saturated solution in water.

Explanation:

The standard state of a material (in chemistry) is defined to compare it with other conditions.

For example the standard state of a gas is defined at 1 atmospheric pressure.

The standard state of a liquid is the pure liquid and for a solid is pure solid.

Similarly for an aqueous solution (a solute dissolved in water) we have defined it as the condition when one mole of a substance is dissolved in one litre of solution (which also means one molar solution).

Thus the given statement is wrong for an aqueous solution.