Ca(OH)2 (s) also known as slaked lime or Ca(OH)2 (aq) also know as lime water. Both forms are produced by adding water to calcium oxide.
Calcium hydroxide can be solid or liquid. The solid form is known as slaked lime and is used to neutralise acidic soils. The liquid form is calcium hydorxide dissolved inw ater to form lime water, used to test for carbon dioxide. If carbon dioxide is blown into lime water, the lime water turns cloudy, this is the test for carbon dioxide.