General Chemistry
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A 1.50 g of heptane (C7H16) with a vapor pressure of 35.5 torr at 20.0 °C is placed in a 2.50 L vessel at 20.0 °C. Assume that the vessel is closed and the volatile substance has reached equilibrium with its vapor, how much liquid heptane (in grams) is left?
Determine the vapor pressure in mmHg for CBr4 at 178 °C using the following information.
normal boiling point = 189.5 °C
∆Hvap = 48.2 kJ/mol
Fluoroform (CHF3) has a vapor pressure (Pvap) of 1605 mmHg at –68.0°C. If the ΔHvap of fluoroform is 16.7 kJ/mol, calculate its ΔSvap.
Toluene, C7H8, is an organic solvent used in paint thinners and markers. Its vapor pressure (Pvap) at 31.8°C and 40.3°C are 40.0 mmHg and 60.0 mmHg respectively. Using this information, estimate the normal boiling point of toluene in °C.
(i) Using the first two temperatures and vapor pressures in the table, calculate the ΔHvap for benzene (C6H6) in kJ/mol.
(ii) Plot the values in the table then determine the ΔHvap for benzene (C6H6) in kJ/mol.
(iii) Compare the values obtained using the two methods.
Cesium iodide, CsI, is commonly used as a scintillator in experimental particle physics. The table below lists the vapor pressure of solid CsI at several temperatures. Use the Clausius-Clapeyron equation to calculate the enthalpy of sublimation of CsI.
Consider the compounds methyl acetate (C3H6O2) and acetone (C3H6O). As the temperature increases, their order of volatility also changes. For this to occur, determine the quantity that must be different for methyl acetate and acetone.
The vapor pressure of pentane (C5H12) is measured at two different temperatures. The vapor pressure of pentane at 15.0°C is 355 torr and the vapor pressure at 40.0°C is 856 torr. Calculate the enthalpy of vaporization of pentane using the Clausius-Clapeyron equation.
The value of vapor pressure of toluene (C7H8) as a function of temperature is shown in the following table:
Determine if this data obeys the Clausius-Clapeyron equation. If yes, calculate the ΔHvap for toluene.
Calculate ΔHvap for carbon tetrachloride if its vapor pressure at 23.0 °C is 100 torr and it has a normal boiling point of 76.7 °C
Calculate the temperature at which cyclooctane will boil at an external pressure of 565 torr. The heat of vaporization is 43.3 kJ/mol and the normal boiling point is 149 °C
Calculate the vapor pressure of Bromine (Br2) at 27.5°C given its heat of vaporization of 30.91 kJ/mol and its normal boiling point of 58.8 °C.
Calculate the heat of vaporization and the normal boiling point of diethyl ether. Use the table below that shows the vapor pressure of diethyl ether at different temperatures.
Calculate the value of ΔH°vap of a liquid that has the vapor pressures of 123.3 Torr and 720.1 Torr at 15.0°C and 70.0° C respectively.
From the results of the previous problem, calculate the normal boiling point of the liquid in °C.
A generic diatomic element in its standard state decomposes as shown below:1/2 A2(g) → A(g)
Calculate the value of the equilibrium constant, K, at 1000 K and 1500 K given that the standard molar Gibbs energy of formation of A(g) is 7.76 kJ•mol-1 at 1000 K and 106.97 kJ•mol-1 at 1500 K
Calculate the value of Δ H°rxn assuming that it is independent of temperature
At the normal boiling point of a liquid, the vapor pressure is ____ atm
Ethanol has a heat of vaporization of 38.56 kJ/mol and a normal boiling point of 78.4°C. What is the vapor pressure of ethanol at 23°C?
Compound X has a vapor pressure of 325 torr at 25 °C and a normal boiling point of 63.2 °C. Find ΔHvap for compound X.