States of Matter and IMF
From the following, this compound would be most likely to form hydrogen bonding interactions between its molecules.
a. NaCl b. Fluoroform (CHF3) c. Ammonia (NH3) d. Acetone (CH3COCH3)
c. Ammonia
On a phase diagram, the triple point is the ....
... temperature at which all three states are in equilibrium
This word describes two substances that are soluble in each other in all proportions without reacting.
Miscible
A face-centered cubic unit cell has this many nearest neighbors.
12
This factor explains why molecules with greater numbers of electrons tend to have higher boiling points.
a. increasing surface area decreases dispersion forces b. increasing polarizability strengthens London dispersion forces c. increasing electronegativity strengthens hydrogen bonding d. increasing effective nuclear charge reduces dispersion forces
(b) increasing polarizability strengthens London dispersion forces
The following substances would exhibit dispersion interactions as their strongest intermolecular forces. (Select all that apply)
a. Borane (BH3) b. Carbon Dioxide (CO2) c. Sulfur Dioxide (SO2) d. Propionaldehyde (CH3CH2CHO) e. Carbon Monoxide (CO)
a. Borane (BH3) b. Carbon Dioxide (CO2) c. Sulfur Dioxide (SO2)
These statements about phase changes are true. Select all that apply.
a. The temperature always increases during a phase change b. Phase changes always occur at the same temperature regardless of the pressure c. Pressure changes can cause changes in phase d. The temperature always remains the same during a phase change
c. Pressure changes can cause changes in phase d. The temperature always remains the same during a phase change
You need to dissolve some octane (C₈H₁₈), but only have limited solvents. Of the following, this would be the best solvent to dissolve octane.
a. water (H₂O) b. methanol (CH₃OH) c. acetonitrile (CH₃CN) d. carbon tetrachloride (CCl₄) e. ammonia (NH₃)
d. octane is nonpolar, and CCl₄ is also nonpolar (“like dissolves like”).
This property makes water unique among substances in how its molecules arrange when it freezes into a solid.
Hydrogen bonding, water becomes more dense as it freezes.
Copper (Cu) would most likely form this type of solid.
a. network solid b. molecular solid c. ionic solid d. metallic solid e. amorphous solid
d. Cu is a metal
Dispersion forces, also known as London dispersion forces, arise from this atomic/molecular property.
a. ionization energy b. total charge c. electronegativity d. polarizability e. polarity
d. polarizability
Use the information below to calculate the heat needed to bring 0.0430 moles of formic acid (CH2O2) from a temperature of 366.2 K to a temperature of 410.0 K(assume pressure is 1.00 atm). Formic acid has a normal melting point of 281.4 K and a normal boiling point of 373.9 K.
Hvap (formic acid) = 46.3 kJ/mol. Heat capacities: Cm(formic acid, liq) = 99.0 J / (mol ·К); Cm(formic acid, g) = 45.2 J / (mol · K)
2.09 kJ
These compounds would likely be miscible with water (H₂O) (select all that apply).
a. CH₄ b. NaCl c. CH₃OH d. CCl₄ e. CO₂
Two liquids are miscible if they can mix together in all proportions to form a single, uniform solution. "Like dissolves like." b. NaCl and c. CH₃OH
A cubic unit cell contains: Element A at all 8 corners of the cube, and Element B at the center of each of the 12 edges of the cube. This many atoms of each element are present in one unit cell.
Corner atoms: 8 corners × ⅛ each = 1 atom of A.
Edge atoms: 12 edges × ¼ each = 3 atoms of B.
A= 1, B= 3
This type of force holds solid CaO together.
a. hydrogen bonding b. metallic bonding c. ionic bonding d. dispersion forces e. covalent bonding
c. ionic bonding, CaO is an ionic compound
The boiling point of propane (C3H8) is 231K while the boiling point of ethane (C2H6) is 185 K. The following factors explain this difference. Select all that apply.
a. Propane has a greater dipole than ethane. b. Propane has a stronger ionic charge than ethane. c. Propane can undergo hydrogen bonding, while ethane cannot. d. Propane is more polarizable than ethane.
d. Propane is more polarizable than ethane.
(C6H12) has a vapor pressure of 97.6 torr when the temperature is 25.0 °C and an enthalpy of vaporization of 33.1 kJ/mol. Determine the vapor pressure of cyelohexane at-18.9°C, the coldest temperature ever recorded in Florida.
9.73 torr
A molecular compound has a solubility in ethanol of 42.0 g·L⁻¹ at 20 °C. This mass of the compound is required to prepare 325 mL of a saturated solution at this temperature.
m=(42.0 g/L)(0.325 L)=13.65 g≈13.7 g
A metal crystallizes in a face-centered cubic (FCC) lattice with lattice constant a=508 pm. The atomic radius r of the metal atom is...
180 pm
This word best describes an extended solid with no band gap, so that electrons can freely move into the conduction band.
a. semiconductor b. conductor c. insulator d. polymer e. allotrope
b. Conductor (no band gap=conductor, large band gap=insulator, small band gap=semiconductor)
This intermolecular force is generally strongest under typical conditions
a. London dispersion b. Dipole–dipole c. Hydrogen bonding d. Ion–dipole e. None of the above
d. Ion-dipole
This liquid, of the following three, is the most volatile at room temperature.
a. diethyl ether (CH₃CH₂OCH₂CH₃) b. ethanol (CH₃CH₂OH) c. 1-propanol (CH₃CH₂CH₂OH)
a. diethyl ether (CH₃CH₂OCH₂CH₃)
Sg= KH Pg = (6.0 x 10-4M/atm)(Pg)= 0.00090M= 1.5atm
A metal forms a body-centered cubic (BCC) crystal with lattice constant a=287 pm. Its molar mass is 55.85 g/ mol. Calculate the density of the metal.
7.9 g/cm3
The boiling point of Br2 is 332.0 K while the boiling point of Kr is 119.8 K. The following factors explain this difference. Select all that apply.
a. Br2 has a stronger ionic charge than Kr b. Br2 can undergo H bonding, while Kr cannot c. Br2 is more polarizable than Kr d. Br2 has a greater mass than Kr e. Br2 has a greater dipole than Kr
c. Br2 is more polarizable than Kr d. Br2 has a greater mass than Kr