Question

A mixture of table salt and ice is used to chill the contents of hand-operated ice-cream makers. what is the molality of salt in a mixture of 2.00 lb of nacl and 12.00 lb of ice if exactly half of the ice melts? assume that all the nacl dissolves in the melted ice.

Answer 1

First, we require the density of ice. This is 57.2 lb/ft³.

Using the following formula, we can calculate the volume of ice:

density = mass / volume
volume = 57.2 / 6 lbs

Volume = 9.53 ft³ = 270 liters

Now, the molarity of a substance is the number of moles of solute per liter of solvent. Now that we have the liters of water, we now calculate the moles of NaCl,

moles = mass / molecular weight
moles = (2 lb * 454 g / 1 lb) / (58.5)
moles = 15.5

molarity = 15.5 / 270
molarity = 0.057 molar