Card # 34 Thermal expansion of liquids Like solid liquids also expand on heating. Since liquids do not have a definite shape they can have only volume expansion. Since the container containing liquid also expands with heat therefore Real Expansion = Apparent Expansion + in a liquid of liquid
Expansion of Container
When a liquid is heated in a container, the container expands first and therefore the level of liquid decreases since the expansion of liquid is more than that of solid, therefore after sometime the liquid expands and its level increases. Coefficient of apparent Expansion for liquid = Ya = (ΔV)a V ΔT = Apparent increase in volume Original volume x rise in temperature Coefficient of real expansion in liquid Yr = (ΔV) r V ΔT = Real expansion in volume Original volume x rise in temperature Coefficient of real Coefficient of Coefficient of expansion of liquid = apparent expansion + expansion of of liquid container
γ
r
=
γ
a
+
γ
g
Anomalous behavior of water Generally all the liquids expand with the rise of temperature. But the volume of water decreases when the temperatures increased from 0o C to 4o C . The volume of water is minimum at 4o C ; therefore its density will be maximum at 4o C . This behavior of water is called anomalous expansion of water.