Specific weight is the weight of the material per unit volume. Water has the specific weight of 62.43 pounds per cubic foot or 9.807 Newtons per cubic meter.

alcohol specific gravity

9.81kN/m3

Depends on the specific gravity of the individual compnents and the specific mix design. Weight can very greatly.

Pressure varies with height as a function of specific weight.

p=p0+specific weight*height

Where height is the distance below the reference pressure p0 (usually at a free surface).