Question
The vapor pressure of water at 45.0 °C is 71.93 mmHg. What is the vapor pressure of water over a solution prepared from 75.0 g of citric acid (C6H8O7) in 0.420 kg of water at this temperature?
Answers
DrBob222
P<sub>H2O></sub> = X<sub>H2O></sub>*<sup>o</sup<sub>H2O</sub>
mols H2O = g/molar mass = 420/18 = ?
mols C6H8O7 = g/molar mass = 75.0/192 = ?
Total mols = mols H2O + mols C6H8O7 = ?
X<sub>H2O</sub = mols H2O/total mols
Calculate mols H2O, mols C6H8O7, total mols, then X<sub>H2O</sub>
Substitute into equation 1 and solve.
Post your work if you get stuck.
mols H2O = g/molar mass = 420/18 = ?
mols C6H8O7 = g/molar mass = 75.0/192 = ?
Total mols = mols H2O + mols C6H8O7 = ?
X<sub>H2O</sub = mols H2O/total mols
Calculate mols H2O, mols C6H8O7, total mols, then X<sub>H2O</sub>
Substitute into equation 1 and solve.
Post your work if you get stuck.
DrBob222
Let me try again. I tried to type in subscripts and superscripts and that didn't work well because I didn't do it right. I think you can interpret this OK. If not let me know.
PH2O = X<sup>o</sup><sub>H2O</sub>
mols H2O = g/molar mass = 420/18 = ?
mols C6H8O7 = g/molar mass = 75.0/192 = ?
Total mols = mols H2O + mols C6H8O7 = ?
XH2O = mols H2O/total mols
Calculate mols H2O, mols C6H8O7, total mols, then XH2O
Substitute into equation 1 and solve.
Post your work if you get stuck.
PH2O = X<sup>o</sup><sub>H2O</sub>
mols H2O = g/molar mass = 420/18 = ?
mols C6H8O7 = g/molar mass = 75.0/192 = ?
Total mols = mols H2O + mols C6H8O7 = ?
XH2O = mols H2O/total mols
Calculate mols H2O, mols C6H8O7, total mols, then XH2O
Substitute into equation 1 and solve.
Post your work if you get stuck.
DrBob222
Sorry again. Replace equation 1 with the following:
P<sub>H2O</sub> = X<sub>H2O</sub>*Psup>o</sup></sub>H2O</sub>
P<sub>H2O</sub> = X<sub>H2O</sub>*Psup>o</sup></sub>H2O</sub>
oobleck
those closing tags are a pain, right? :-(
DrBob222
A REAL pain.