Vapor pressure question ?
What is the vapor pressure over a 30 degree C water solution containing 652 g of sucrose, C12H22O11, per liter of solution? (Assume the solution behaves ideally. The vapor pressure over pure water at this temperature is 31.8 torr. Sucrose is nonvolatile. The density of the solution is 1.61 g/mL). Please explain how to calculate this. Also, why is the information provided in the parenthesis important to this problem? Thanks!
What is the vapor pressure of ethanol at 13 C?
Use the Clausius–Clapeyron Equation, and remember that the vapor pressure of any liquid is equal to the atmospheric pressure at its boiling point. ln(P2/P1) = (∆Hvap/R) (1/T1 - 1/T2); Substituting and converting temperatures to Kelvins, ln(P2 / 1 atm) = [(38560 J) / (8.31442 J/K·mol)] (1/351.55 K - 1/286.15 K) Solving, P2 = 0.049 atm.
What is vapour pressure?
All liquids exhibit tendency for evaporation. Evaporation takes place at the surface of liquid. If the kinetic energy of liquid molecules overcomes the intermolecular force of attraction in the liquid state then the molecules from the surface of liquid escape into space above surface. The process is called 'evaporation'. If evaporation is carried out in a closed container system then the vapours of liquid remains in contact with surface of liquid. Like gas molecules vapour of molecules also execute continuous random motion. During this motions, molecules collide with each other and also with the walls of the container, losses their energy and returns back to liquid state. This process is called as 'condensation'.Evaporation and condensation are continues processes. Hence, after some time an equilibrium is established, at constant temperature between evaporation and condensation. At equilibrium number of molecules in vapour state remains constant at constant temperature."The pressure exerted by vapours of liquid on the surface of liquid when equilibrium is established between liquid and it's vapour is called VAPOUR PRESSURE of liquid." The vapour pressure of the liquid depends on the nature of the liquid and temperature. With increase of intermolecular force of attraction vapour pressure of liquid decrease and with rise of temperature vapour pressure of liquid increases. Mercury manometer may be used to determine vapour pressure of liquid.
What is vapor pressure?
Vapour pressure is the pressure exerted by the vapours of a liquid on the walls of the container in which it is enclosed.
Vapor Pressure of a solution of 12 g C6H12O6 in 88.5 g CH3OH?
First you must find the mol values of both substances. Glucose (C6H1206): 12 g * 1 mol/ 180.16 g = 0.067 mol Methanol (CH3OH): 88.5 g * 1 mol/ 32.04 g = 2.76 mol Now using this, we find the mol fraction (X) of each substance in the mixture. Mol fraction = Mols of individual substance/ Total mols. Since we have 0.067 mol glucose and 2.76 mol of methanol, our total mol value is 2.83 mol. Mol fraction(Glucose)= 0.067/2.83 = 0.0237 Mol fraction(Methanol) = 2.76/2.83 =0.957 If the vapor pressure of glucose is not given, we assume it's nonvolatile, meaning it does not undergo a phase change into its gaseous form. The total vapor pressure of a solution is determined by adding together the vapor pressure of each solute in the solution. P(solution) = (mol fraction glucose)(vapor pressure of glucose) + (mol fraction methanol)(vapor pressure of methanol) Since glucose is nonvolatile, it has a vapor pressure of 0. Therefore, glucose does not contribute to the vapor pressure of the solution, so the problem now becomes: P(solution) = (mol fraction methanol)(vapor pressure of methanol) Plug in and solve. P(solution) = (0.957)(140 mmHg) P(solution) = 133.98 ~ 134 mmHg The solution has a vapor pressure of 134 mmHg.
How to determine vapor pressure?
mmoles acetone = 31.5 g /58.08 g/mol=0.542 moles ethyl acetate = 25.0 g /88.105 g/mol=0.284 mole fraction acetone = 0.542 / 0.542 + 0.284 =0.656 mole fraction ethyl acetate = 0.284 / 0.542 + 0.284= 0.344 use the Raoult's law p= p°X vapor pressure acetone = 285 x 0.656 =187 mm Hg vapor pressure ethyl acetate = 118 x 0.344 =40.6 mm Hg total vapor pressure = 187 + 40.6= 228 mm Hg
What is the vapor pressure of a solution of 14.5g of glucose in 78.5g of methanol at 27∘C?
Answer Molar mass of glucose is 180.16 g/mol Moles of glucose in soln is 14.5/180.16 = 0.0804 Molar mass of methanol is 32.04 g/mol Moles of methanol in soln is 78.5/32.04 = 2.45 Total moles = 2.5305 Mole fraction of methanol is 2.45/2.5305 = 0.9681 By Raoult's law assuming the the soln is an ideal soln Partial pressure of methanol = vap pr * mole fraction = 0.9681*140 = 135.54 mm Vap pr of soln = partial pr of methonol ( Glucose being non volatile)= 135.54 mm
CHEMISTRY HELP! What is the vapor pressure in mmHg, of a solution.......?
Vapor pressure of a solution = mole fraction of the solvent x vapor pressure of the solvent. 500.0g x 1mole/ 18.02g = 27.75moles water. 18.3g x 1mole / 58.5g = 0.313moles NaCl → 0.313moles Na+ and 0.313moles Cl-. Total moles = 27.75 + 0.313 + 0.313 = 28.38moles mole fraction water = 27.72 / 28.38 = 0.9769 vapor pressure = 233.7 x .9769 = 228.3mmHg.
What is equilibrium vapour pressure?
Equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indication of a liquid's evaporation rate.