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I'm confused about two questions from Examkrackers 1001 Physics, #513 and #520
513. What is the vapor pressure of a 2 m sodium chloride solution at 100 C
EK Solution: 2 m NaCl split into 2 m Na and 2 m Cl. Consider a 1 liter solution. That's 56 moles of water and 4 moles of solute. Or 56/(56+4), or 0.93 of normal vapor pressure, 760. So the answer is (0.93)(760).
This makes complete sense to me.
Now, here's where I get confused.
520. 58 grams of NaCl are added to 1 liter of pure water. The solution is heated to 100 C. What is the vapor pressure?
MY solution: I follow the same process. 58 grams NaCl is 1 mol NaCl, or 1 mol Na and 1 mol Cl. So 56/(56+2)
EK solution: They say it's only 56/(56+1)
Why is it not 56/(56+2) for the mol fraction in number 520?
513. What is the vapor pressure of a 2 m sodium chloride solution at 100 C
EK Solution: 2 m NaCl split into 2 m Na and 2 m Cl. Consider a 1 liter solution. That's 56 moles of water and 4 moles of solute. Or 56/(56+4), or 0.93 of normal vapor pressure, 760. So the answer is (0.93)(760).
This makes complete sense to me.
Now, here's where I get confused.
520. 58 grams of NaCl are added to 1 liter of pure water. The solution is heated to 100 C. What is the vapor pressure?
MY solution: I follow the same process. 58 grams NaCl is 1 mol NaCl, or 1 mol Na and 1 mol Cl. So 56/(56+2)
EK solution: They say it's only 56/(56+1)
Why is it not 56/(56+2) for the mol fraction in number 520?
