The molecular mass of butanol, C4H,OH, is 74.14; that of ethylene glycol, CH2(OH)CH,OH, is 62.08, yet their boiling points are 117.2 °C and 174 °C, respectively. Explain the reason for the difference. The two hydroxyl groups in ethylene glycol provide more locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably decreases the boiling point The two hydroxyl groups in ethylene glycol provide less locations for the formation of hydrogen bonds. The existence of less hydrogen bonds considerably increases the boiling point The two hydroxyl groups in ethylene glycol provide more locations for the formation of hydrogen bonds. The existence of more hydrogen bonds considerably increases the boiling point

Explain the following observations by reference to the type of bonding present and/or the forces between organic molecules: The compounds ethanol (CH3CH2OH) and formic acid (HCOOH) have molecular masses of 46 gmol-1 but different boiling points: Compound Boiling point   Ethanol 78.5 °C Formic acid 100.8 °C

Benzene is frozen @ 5.5 deg. C, then brought to a boil @ 80.1 deg. C . If you are in the room where it is boiled. When you smell the odor of the vapor, what is it that you are smelling?

3. Maximum solubility of an ionic compounds in water depend on different sets of conditions. Out of five sets of conditions (given below), which one is the best for getting maximum solubility? A. The magnitude of the lattice energy should be large, and the enthalpy of hydration of the ions should be large. B. The enthalpy of hydration (Delta H) of the cation should be equal to the enthalpy of hydration of the anion, regardless of the magnitude of the lattice energy C. The magnitude of the lattice energy should be small, and the enthalpy of hydration of the ions should be small.   D. The magnitude of the lattice energy should be small, and the enthalpy of hydration of the ions should be large. E. The magnitude of the lattice energy should be large, and the enthalpy of hydration of the ions should be small.

Based on the thermodynamic properties provided for water, determine the amount of energy needed for 2.00 kg of water to go from -16.0 °C to 69.0 °C. Property Melting point Boiling point AHfus AHvap Cp (s) Cp (1) Cp (8) kJ Value 0.0 100.0 6.01 40.67 37.1 75.3 33.6 Units °℃ °C kJ/mol kJ/mol J/mol. °C J/mol • °C J/mol. °C

The vapor pressure of water at 25 C is 23.76 Torr. Estimate the vapor pressure of water at the same temperature in the presence of 2.5 atm of an inert ideal gas that is insoluble in water (e.g., helium). The molar mass of water is 18.02 g/mol, and the density is 0.998 g/cm3.

(3) Vapor pressure of liquid ethanol is 7291 Pa at 20°C. (a) one student reports that the vapor pressure is 31741 Pa at 52°C. Another student reports it to be 31741 Pa at 502°C. Which of the results is correct? Why? (b) calculate the normal boiling temperature of ethanol (assume Patm=101,325Pa).

kJ The enthalpy of vaporization of Substance X is 5.00 and its normal boiling point is -66. °C. Calculate the vapor mol pressure of X at -87. °C. Round your answer to 2 significant digits. || atm x10

(a) Consider a substance where the intermolecular forces hold the molecules in fixed rigid positions. What is the process called when enough heat has been added to the substance so that the molecules begin to flow? (b) Consider a substance where the intermolecular forces hold the molecules in close contact with each other, but the molecules can flow. What is the process called when enough heat has been added to the substance so that the molecules escape each other? (c) Consider a substance where the intermolecular forces hold the molecules in fixed rigid positions. What is the process called when enough heat has been added to the substance so that the molecules can escape each other?