What is the vapor pressure in mmHg of a solution of 12.0 g NaF dissolved in 200.0 g water at 60 °C if NaF is a nonvolatile solute and completely dissolved in water? The vapor pressure of water at 60°C is 149 mmHg.

• A. 138 mmHg
• B. 142 mmHg
• C. 145 mmHg
• D. 149 mmHg

Answer: (B)