How can I calculate salinity if all I am given is volume and freezing point?

Answer 1

I'm assuming you're dealing with placing salt in water

there is an equation that relates the concentration of a solute to the freezing point depression for the solution

delta T = (m)(Kf)

delta T is the CHANGE from the normal freezing point of the pure solvent to the freezing point of the solution

m is the molality of the solute

Kf is the molal freezing point constant - it depends on the solvent - for water it is 1.86 degC / m

solve the equation for m and then since salinity is g salt / kg and m is mole of salt / kg water, you would have to change moles to grams using molar mass

Answer 2

You should be able to find concentration of solute (in moles per kg of solvent) using freezing point depression. From there you'll need to convert the units to the desired ones for salinity.