Question

Calculate normal BP of seawater. Seawater is about 3.5% (W/W) dissolved solids, assume all of it is NaCl. KB of water is 0.52°C kg/mol

Answer 1

To calculate the normal boiling point (BP) of seawater, use the equation BP = KB x i x m, where KB is the boiling point elevation constant for water, i is the van 't Hoff factor, and m is the molality of the solution. First, calculate the molality of the NaCl solution by dividing the mass of NaCl by the molar mass of NaCl. Then, substitute the values into the boiling point elevation equation and solve for the BP.

Step-by-step explanation:

The normal boiling point (BP) of seawater can be calculated using the formula:
BP = KB x i x m

where:

KB is the boiling point elevation constant for water (0.52°C kg/mol),

i is the van 't Hoff factor which is the number of particles the solute dissociates into in solution (2 for NaCl),

and m is the molality of the solution.

First, we need to calculate the molality of the NaCl solution. To do this, we divide the mass of NaCl by the molar mass of NaCl:

molality of NaCl = (mass of NaCl / molar mass of NaCl) / mass of water

Next, we substitute the values into the boiling point elevation equation:

BP = (0.52°C kg/mol) x 2 x molality of NaCl

Finally, we calculate the BP by substituting the molality value and solve the equation:

BP = (0.52°C kg/mol) x 2 x molality of NaCl