Question

Why does liquid have to cofficients of expansion​

Answer 1

*coefficients
The ratio of apparent increase in volume of the liquid per unit rise of temperature to the original volume is called its coefficient of apparent expansion.So a liquid has two coefficients of expansion.Measurement of the expansion of a liquid must account for the expansion of the surface as well

Answer 2

The ratio of apparent increase in volume of the liquid per unit rise of temperature to the original volume is called its coefficient of apparent expansion. ... Thus a liquid has two coefficients of expansion. Measurement of the expansion of a liquid must account for the expansion of the container as well.