Calculate the boiling point of a 1.5 m aqueous solution of nacl. the boiling point constant of water is 0.512 °c/m. remember, m is a unit for molality.
a.98.5 °c
b.100.0 °c
c.100.8 °c
d.101.5 °c

To determine boiling point, we have the equation: ΔT = mK; where ΔT refers to the boiling-point elevation, m refers to molality which is in the unit mol/kg, and K is the molal boiling-point elevation constant.

In this problem, water is the solvent and NaCl is the solute. Note that 100°C is the boiling point of water. We substitute the equation:
ΔT = (1.5 m)(0.512 °C/m) 
ΔT = 0.768°C
This is the change in temperature. To find the boiling point of the whole solution, we add the boiling point of the solvent:
100°C +  0.768°C = 100.768°C ≈ 100.8°C

The answer is C.