Ethanol, with AHvap = 40.5 kJ mol-1, has a higher AHvap than methanol, which is 35.2 kJ mol1, due to its larger size and greater intermolecular forces. Because the AHvap for ethanol is larger, we would expect that for the two liquids to reach the same vapor pressure, the temperature for ethanol would have to be higher. If the vapor pressure is 0.0992 atm at 27.3 °C, what would the temperature be when the vapor pressure is 8.53 atm? The temperature will be i 140 ! К.

Ethanol, with AHvap = 40.5 kJ mol-1, has a higher AHvap than methanol, which is 35.2 kJ mol1, due to its larger size and greater intermolecular forces. Because the AHvap for ethanol is larger, we would expect that for the two liquids to reach the same vapor pressure, the temperature for ethanol would have to be higher. If the vapor pressure is 0.0992 atm at 27.3 °C, what would the temperature be when the vapor pressure is 8.53 atm? The temperature will be i 140 ! К.

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter9: Liquids And Solids

Section: Chapter Questions

Problem 64QAP

See similar textbooks

Similar questions

What is U when 1.00 mol of liquid water vaporizes at 100C? The heat of vaporization, Hvap, of water at 100C is 40.66 kJ/mol.
he enthalpy (H)of vaporization of water is about seven times larger than water’s enthalpy fusion(41kJ/molvs.6kJ/mol). What does this tell us about the relative similarities among the solid, liquid, and gaseous states of water?
Why are steam burns so much worse than water burns even if the H2O is at the same temperature for both phases? Hint: Consider the heat of vaporization of water.
Classify each of the following statements as true or false. a Intermolecular attractions are stronger in liquids than in gases. b Substances with weak intermolecular attractions generally have low vapor pressures. c Liquids with high molar heats of vaporization usually are more viscous than liquids with low molar heats of vaporization. d A substance with a relatively high surface tension usually has a very low boiling point. e All other things being equal, hydrogen bonds are weaker than induced dipole or dipole forces. f Induced dipole forces become very strong between large molecules. g Other things being equal, nonpolar molecules have stronger intermolecular attractions than polar molecules. h The essential feature of a dynamic equilibrium is that the rates of opposing changes are equal. i Equilibrium vapor pressure depends on the concentration of a vapor above its own liquid. j The heat of vaporization is equal to the heat of fusion, but with opposite sign. k The boiling point of a liquid is a fixed property of the liquid. l If you break shatter an amorphous solid, it will break in straight lines, but if you break a crystalline solid, it will break in curved lines. m Ionic crystals are seldom soluble in water. n Molecular crystals are nearly always soluble in water. o The numerical value of heat of vaporization is always larger than the numerical value of heat of condensation. p The units of heat of fusion are kJ/gC. q The temperature of water drops while it is freezing. r Specific heat is conerned with a change in temperature.
The hydrogen fluoride molecule, HF, is more polar than a water molecule, H2O (for example, has a greater dipole moment), yet the molar enthalpy of vaporization for liquid hydrogen fluoride is lesser than that for water. Explain.
Consider a substance X with a Hvap = 20.3 kJ/mol and Hfus = 9.0 kJ/mol. The melting point, freezing point, and heat capacities of both the solid and liquid X are identical to those of water. a If you place one beaker containing 50 g of X at 10C and another beaker with 50 g of H2O at 10C on a hot plate and start heating them, which material will reach the boiling point first? b Which of the materials from part a, X or H2O, would completely boil away first? c On a piece of graph paper, draw the heating curve for H2O and X. How do the heating curves reflect your answers from parts a and b?
Carbon disulfide, CS2 is a volatile, flammable liquid. It has a vapor pressure of 400.0 mmHg at 28.0C and 760.0 mmHg at 46.5C. What is the heat of vaporization of this substance?
The following data are the equilibrium vapor pressure of limonene, C10H16, at various temperatures. (Limonene is used as a scent in commercial products.) (a) Plot these data as ln P versus 1/T so that you have a graph resembling the one in Figure 11.13. (b) At what temperature does the liquid have an equilibrium vapor pressure of 250 mm Hg? At what temperature is it 650 mm Hg? (c) What is the normal boiling point of limonene? (d) Calculate the molar enthalpy of vaporization for limonene using the Clausius-Clapeyron equation.
Ethylene glycol 1HOCH2CH2OH2, the major substance inantifreeze, has a normal boiling point of 198 °C. Bycomparison, ethyl alcohol 1CH3CH2OH2 boils at 78 °Cat atmospheric pressure. Ethylene glycol dimethyl ether1CH3OCH2CH2OCH32 has a normal boiling point of 83 °C,and ethyl methyl ether 1CH3CH2OCH32 has a normalboiling point of 11 °C. (a) Explain why replacement of ahydrogen on the oxygen by a CH3 group generally resultsin a lower boiling point. (b) What are the major factorsresponsible for the difference in boiling points of the twoethers?
A 791.0 g sample of acetone sitting in the lab has a temperature of 21.7°C. How much heat would be involved in lowering the temperature of the acetone to -200.0°C? Formula: C3H6OMelting Point: -94.0°CBoiling Point: 56.0°CDensity of liquid: 0.791 g/mLHeat of Fusion: 98.14 J/gHeat of vaporization: 538.9 J/gSpecific heat capacity (solid): 1.653 J/g°CSpecific heat capacity (liquid): 2.161 J/g°CSpecific heat capacity (gas): 1.291 J/g°C
A 0.554 g0.554 g sample of steam at 106.0 ∘C106.0⁢ ∘C is condensed into a container with 5.20 g5.20 g of water at 16.4 ∘C.16.4⁢ ∘C. What is the final temperature of the water mixture if no heat is lost? The specific heat of water is 4.18 J g⋅ ∘C,4.18 J g⋅ ∘C, the specific heat of steam is 2.01 J g⋅ ∘C,2.01 J g⋅ ∘C, and Δ?vap=40.7 kJ/mol.
A 0.538 g0.538 g sample of steam at 105.3 ∘C105.3⁢ ∘C is condensed into a container with 5.77 g5.77 g of water at 16.1 ∘C.16.1⁢ ∘C. What is the final temperature of the water mixture if no heat is lost? The specific heat of water is 4.18 J g⋅ ∘C,4.18 J g⋅ ∘C, the specific heat of steam is 2.01 J g⋅ ∘C,2.01 J g⋅ ∘C, and Δ?vap=40.7 kJ/mol.Δ⁢�vap=40.7 kJ/mol. ?f=�f=