Exam 12: Intermolecular Attractions and the Properties of Liquids and Solids

A particular solid, crystalline substance has a high melting point and is very hard. It is a non-conductor of electricity, even in the molten state. Most likely, what type of solid is this substance?

The heating of a liquid above its boiling point temperature without boiling occurring is called ________.

A substance, B, has a normal boiling point of +89.3°C, and a heat of vaporization of 260 J/g. How much heat is required to change 150 grams of B from a liquid at 89.3°C to a gas at 89.3°C?

Given the following substances and their normal boiling points, in °C: Which ranking correctly lists some of these liquids in order of increasing intermolecular forces at 20°C?

Which one of the following substances is most likely composed of ions rather than distinct formula units, when it is in the solid state?

Amorphous solids are highly ordered crystals, and they must contain silicon or carbon to be classified as an amorphous solid.

A substance has a melting point of -25.0°C, an enthalpy of fusion of 1200 J g^-1,and specific heats for the solid and the liquid are 3.00 and 6.20 J g^-1 °C ^-1, respectively. How much energy is needed to change 150 grams of the substance from a solid at -40.0°C to a liquid at +70.0°C?

Arrange these compounds in order of increasing intermolecular forces: CBr₄, CCl₄, CF₄, CH₄, CI₄.

Tungsten metal (W)exists as a body-centered cubic structure. How many tungsten atoms are within a unit cell of tungsten metal?

The temperature at which the vapor pressure is equal to 1 atm, 760 torr, or 101,325 Pa is defined as

Hexane (C₆H₁₄)boils at 68.73°C at 760 torr. The heat of vaporization for hexane is28.9 kJ/mol. What is the vapor pressure of hexane at 30°C?

Why does CH₃-CH₂-O-H have a higher boiling point than CH₃- O-CH₃ even though they have the same formula, C₂H₆O?

The molar enthalpy of vaporization of carbon disulfide is 26.74 kJ/mol, and its normal boiling point is 46°C. What is the vapor pressure of CS₂ at 0°C?

Which of the following organic liquids would best demonstrate wetting on a clean glass surface?

A substance has a melting point of +25.0°C, an enthalpy of fusion of 1200 J g ¹, and specific heats for the solid and the liquid are 3.00 and 6.20 J g^-1 °C ^-1, respectively. How much energy is needed to change 150 grams of the substance from a solid at -40.0°C to a liquid at +70.0°C?

X-ray diffraction measurements on a newly discovered crystalline form of La revealed that La crystallizes in a body-centered cubic lattice in which the unit cell edge length is 426.3 picometers. Calculate the atomic radius of the La atoms in this crystal, based on the assumption that the atoms are tightly packed in the unit cell.Hint: Find the length of the cell body diagonal using the Pythagorean theorem.

The triple point of a substance is the temperature and pressure at which

Above a substance's critical point, its gas phase becomes like a liquid and the liquid becomes like a gas.

A new compound, vitellium oxide, has been discovered. X-ray crystallographic studies reveal that it has a cubic unit cell with a vitellium ion at each of the corner lattice points, a vitellium ion at the geometric center of the unit cell, and an oxide ion in the center of each of the cube faces in the unit cell. Based on this structure, the correct formula should be

Which of the following liquids, at the same temperature, has the lowest vapor pressure?