General Chemistry II - January
How many types of atoms are in the simple cubic unit cell?
1 type of atom (simple cubic).
What are three statements relating to the relative strength, physical properties, and charges of intermolecular forces?
1. Intermolecular forces are generally weaker than bonding forces. 2. The strength of the intermolecular force(s) in a substance determines the physical properties of that substance's phases. 3. Intermolecular forces involve small or partial charges that are far apart and relatively weak.
Non-bonding/intermolecular forces exist in what six forms (from strongest to weakest)?
1. Ion-Dipole. 2. Hydrogen bond. 3. Dipole-dipole. 4. Ion-induced dipole. 5. Dipole-induced dipole. 6. Dispersion.
What are the three types of unit cells in crystals?
1. Simple cubic unit cell. 2. Body-centered unit cell. 3. Face-centered unit cell.
How many types of atoms are in the body-centered unit cell?
2 types of atoms (body-centered).
How many types of atoms are in the face-centered unit cell?
2 types of atoms (face-centered).
What type of solution is exhibited in ion-induced dipole forces?
A nonpolar solute in a polar solvent that also contains dissolved ions.
What type of solution is exhibited in dipole-induced dipole forces?
A nonpolar solute in a polar solvent.
What is doping?
Adding small amounts of different elements into the crystal structure to enhance a certain aspect/trait, such as conductivity.
What type of solution is exhibited in ion-dipole forces?
An ionic solute in a polar solvent.
What is a crystal defect?
Any irregularity in the structure of a crystal formation.
Which of the following statements correctly defines colligative properties? A. Properties that depend on the number of different solutes present in the solution. B. Properties that are observed only for aqueous solutions. C. Properties of a solution that depend only on the number of dissolved solute particles. D. Properties of a solution that depend on the nature of the dissolved solute particles.
C. Properties of a solution that depend only on the number of dissolved solute particles.
Particles within a crystal are arranged in an orderly 3D array called what?
Crystal lattice (orderly 3D).
A p-type semiconductor is formed by doping silicon with any Group 3A element. This _____ the number of valence electrons available, creating _____ sites into which Si electrons can migrate. This increases the conductivity of the material.
Decreases; positive.
What primary intermolecular force is exhibited in the solution I2 in hexane (C6H14)?
Dispersion forces (primary force in solution).
What type of substance is matched with the behaviours of a nonelectrolyte?
Does not dissociate at all in aqueous solution; no ions are produced and the solution does not conduct an electric current.
What term refers to intentionally adding small amounts of other elements to increase/decrease a specific characteristic of a crystal (such as to increase the # of valence e-'s in the conduction bands, to enhance conductivity)?
Doping (definition).
What type of phase change is fusion? (endo- vs. exo-)
Endothermic (fus).
What type of phase change is sublimation? (endo- vs. exo-)
Endothermic (subl).
What type of phase change is vaporization? (endo- vs. exo-)
Endothermic (vap).
What type of phase change is condensation? (endo- vs. exo-)
Exothermic (cond).
What type of phase change is deposition? (endo- vs. exo-)
Exothermic (depo).
What type of phase change is freezing? (endo- vs. exo-)
Exothermic (fre).
Condensation, freezing, and deposition are _____ phase changes, whereas fusion, vaporization, and sublimation are _____ changes.
Exothermic; endothermic.
True or False: A bond between O and H inside any molecule is known as an H-bond.
False; Hydrogen bonds are intermolecular forces, meaning they exist between different molecules, not inside them.
A solution forms when the attractive ______ between the solute and solvent are ______ in strength to the solvent-solvent and solute-solute attractions and are therefore able to replace them.
Forces; similar (fill-in-the-blanks).
Liquid to solid state is called what?
Freezing.
Solid to liquid state is called what?
Fusion or melting.
What primary intermolecular force is exhibited in the solution CH3OH in H2O?
Hydrogen bonding (primary force in solution).
What is the strongest intermolecular force between nonpolar/electrically neutral species?
Hydrogen bonds (strength).
What intermolecular force exists when an ionic compound is dissolved in a polar solvent (such as H2O)?
Ion-dipole forces (ionic in polar).
What primary intermolecular force is exhibited in the solution NaCl in CH3CH2OH?
Ion-dipole forces (primary force in solution).
What intermolecular force involves the attraction between a charged molecule (ion) and a nearby polar molecule?
Ion-dipole forces (type of intermolecular).
Salts are soluble in water because the ______-______ attractions between ______ and water are ______ in strength to the strong attractions between the ions and the strong H-bonds between water molecules, so they ______ replace each other.
Ion-dipole; ion; similar; can (fill-in-the-blanks).
The attractive force in ion-dipole interactions is important when a(n) ______ compound dissolves in a polar solvent such as H2O.
Ionic (fill-in-the-blanks).
Bonding/intramolecular forces exist in what three main forms?
Ionic bonds, covalent bonds, and metallic bonds.
What type of substance is matched with the behaviours of a weak electrolyte?
Low % dissociation in aqueous solution; a few ions are produced and the solution conducts poorly.
The ratio mol of solute/L of solution is called the ______ of a solution (symbol M), whereas the ______ (symbol m) of the solution is expressed as mol of solute/kg of solvent. For an aqueous solution, these two quantities will be very similar if the solution concentration is ______.
Molarity; Molality; low (fill-in-the-blanks).
When two polar molecules are close to each other they will orient themselves so that the positive pole of one molecule attracts the ______ pole on the adjacent molecule.
Negative (fill-in-the-blanks).
What term refers to how well the e- cloud of an atom responds to its electrical environment?
Polarizability (definition).
What type of solution is exhibited in dispersion forces?
Present in all solutions; principal intermolecular force when both solvent and solute are nonpolar.
What type of substance is matched with the behaviours of a strong electrolyte?
Shows 100% dissociation in aqueous solution; ions are produced and the solution conducts electricity well.
What is the substance being dissolved called?
Solute (definition).
What type of mixture is a homogeneous mixture where the particles are too small to be visible; particles are distributed evenly in the solvent?
Solution (definition).
What is the substance that dissolves the solute called?
Solvent (definition).
Solid to gas state is called what?
Sublimation.
What type of mixture is a heterogeneous mixture containing particles large enough to be seen by the naked eye; particles will settle out on standing?
Suspension (definition).
Which type of unit cell has 8 as its coordination number?
The body-centered unit cell (coordination number).
Which type of unit cell has atoms in the corners of their cube formation, and one in the centre?
The body-centered unit cell (definition).
Identical particles lie at each corner and in the center of the cube in what cell type?
The body-centered unit cell (identical particles).
What term refers to the amount of nearest neighbors for a particle in the unit cell of a crystal?
The coordination number (definition).
Which type of unit cell has 12 as its coordination number?
The face-centered unit cell (coordination number).
Which type of unit cell has 6 as its coordination number?
The simple cubic unit cell (coordination number).
Which type of unit cell has atoms in only the corners of their cube formation?
The simple cubic unit cell (definition).
The centers of eight identical particles define the corners of a cube in what unit cell type?
The simple cubic unit cell (identical particles).
What is occurring from A to B on the heating curve?
The substance is in the solid phase.
What is a crystal lattice?
The symmetrical 3D arrangement of atoms/points within a crystal.
True or False: All particles exhibit dispersion forces.
True; All particles exhibit dispersion forces.
True or False: Dipole-dipole forces are the forces of attraction between two polar molecules.
True; Dipole-dipole forces are the attractive forces between the oppositely charged ends of two polar molecules.
True or False: For a dilute aqueous solution molality and molarity are nearly equal.
True; Since the density of water is 1 g/mL, the mass of the solvent and the volume of the solution will be very close as long as the solution is dilute.
True or False: For two compounds of similar molar mass, the greater the molecular dipole moment, the stronger the dipole-dipole forces.
True; When two compounds have a similar molar mass, the dipole-dipole forces increase in strength as the molecular dipole moment gets larger.
What is the term for the smallest amount of particles that retain the shape of the crystal (if repeated in all directions)?
Unit cell (definition).
What is the simplest repeating unit of a crystal called?
Unit cell (simplest repeating).
Liquid to gas state is called what?
Vaporization.
What is a Hydrogen bond?
When hydrogen is covalently bonded to N, O, or F, therefore creating the possibility of attraction between it and another nearby molecule with a lone pair of e- attached to its N, O, or F.
What is the equation for heating/cooling within a phase (when mass is given)?
q = m c ΔT
Which equation should be used to calculate the phase change when a given molar amount of H2O vapor is condensed?
q = n (-ΔH^o fus)
What is the equation for heating/cooling within a phase (when moles are provided)?
q = n C ΔT
Which equation should be used to calculate the heat change when a given molar amount of H2O is heated from 15 degrees C to 95 degrees C?
q = n C ΔT (example).
What is the equation for heating/cooling during a phase change?
q = n ΔH^o change
Which of the following is an intermolecular force exhibited in a solution of CH3OCH3 in CH3OH? Select all that apply. - Dipole-dipole forces. - Ion-dipole forces. - Hydrogen bonding. - Dispersion forces.
- Dipole-dipole forces. - Hydrogen bonding. - Dispersion forces.
Which of the following statements correctly describe the molality and molarity of a solution? Select all that apply. - m will change if the temperature of the solution changes. - For a dilute aqueous solution molality and molarity are nearly equal. - M must be calculated using the volume of the solution, not the volume of the solvent. - Both molarity and molality express concentration in terms of moles of solute. - The unit of molality is m.
- For a dilute aqueous solution molality and molarity are nearly equal. - M must be calculated using the volume of the solution, not the volume of the solvent. - Both molarity and molality express concentration in terms of moles of solute.
Which of the following statements correctly describe the behavior of different types of substances in an aqueous solution? Select all that apply. - Nonelectrolytes do not produce ions in solution. - CH3COOH is a weak electrolyte, and when this substance is dissolved in H2O, there will be a mixture of CH3COOH molecules, CH3COO- ions, and H3O+ ions. - MgCl2 is a strong electrolyte and 1 mol of MgCl2 will produce 3 moles of ions in aqueous solution. - Glucose (C6H12O6) is a nonelectrolyte and produces no solute particles when dissolved in water. - Strong electrolytes always produce concentrated solutions.
- Nonelectrolytes do not produce ions in solution. - CH3COOH is a weak electrolyte, and when this substance is dissolved in H2O, there will be a mixture of CH3COOH molecules, CH3COO- ions, and H3O+ ions. - MgCl2 is a strong electrolyte and 1 mol of MgCl2 will produce 3 moles of ions in aqueous solution.
Which of the following options describe situations in which hydrogen bonding will be observed between the solute and the solvent? Select all that apply. - Solvent contains N, O, or F; solute contains OH or NH groups. - As long as the solvent can form hydrogen bonds, hydrogen bonding is observed between solute and solvent. - Solvent and solute both contain OH or NH groups. - Solvent contains OH or NH groups, solute contains N, O, or F atoms. - Solvent and solute both contain O, N, or F.
- Solvents contain N, O, or F; solute contains OH or NH groups. - Solvent and solute both contain OH or NH groups. - Solvent contains OH or NH groups, solute contains N, O, or F atoms.
Which of the following statements correctly describe the behavior of solutions, suspensions, and colloids? Select all that apply. - A colloid, like a suspension, is not stable over time. - A solution will settle out on standing. - The particles in a solution are evenly distributed in the solvent. - The major factor that causes suspension, solutions, and colloids to differ is particle size. - The particles in a colloid are smaller than those in a suspension.
- The particles in a solution are evenly distributed in the solvent. - The major factor that causes suspension, solutions, and colloids to differ is particle size. - The particles in a colloid are smaller than those in a suspension.
Which of the following options correctly describes the effect of temperature on the solubility of a solid in a given solvent? Select all that apply. - All solids increase in solubility as temperature increases. - If ΔHsoln < 0, the solid will decrease in solubility as temperature increases. - There is no clear correlation between ΔHsoln and solubility at different temperatures. - In general, solids are more soluble at higher temperatures than at lower temperatures.
- There is no clear correlation between ΔHsoln and solubility at different temperatures. - In general, solids are more soluble at higher temperatures than at lower temperatures.
Which of the following options correctly describe the different ways of expressing the concentration of a solution? Select all that apply. - Mass % is only used when both the solute and the solvent are solids. - To calculate mole fraction for a given mass of a reactant or product, the masses of all solution components must be known. - The unit for *molality* (symbol *m*) is mol/kg. - Molarity = mol of solute / volume of solvent.
- To calculate mole fraction for a given mass of a reactant or product, the masses of all solution components must be known. - The unit for molality (symbol m) is mol/kg.
What is the best definition for polarizability?
A measure of how the e- cloud around an atom interacts with its electronic environment.
Why is hydrogen bonding observed in a solution of CH3OCH3 in CH3OH?
Although hydrogen bonding is not possible between two molecules of CH3OCH3, this solute is capable of accepting hydrogen bonds from the solvent CH3OH because it contains an O atom.
What type of mixture is a dispersion of particles in a dispersing medium; particles are too small to settle out but large enough to scatter light?
Colloid (definition).
Gas to liquid is called what?
Condensation.
The number of nearest neighbors for a particle (atoms or ions) in the unit cell of a crystal is called the _____ number of the particle.
Coordinate (fill-in-the-blanks).
What is the term that refers to any variety of disruptions in the regularity of a crystal formation?
Crystal defects (definition).
Gas to solid state is called what?
Deposition.
The attraction between an ion and a nearby polar molecule is called an ion-______ interaction.
Dipole (fill-in-the-blanks).
What type of intermolecular force exists between two polar molecules, aligned + to -?
Dipole-dipole forces (type of intermolecular).
What primary intermolecular force is exhibited in the solution O2 (g) in aqueous solution?
Dipole-induced dipole (primary force in solution).
I2 (s) has a very low solubility in H2O (l) because the weak ______ forces between I2 and H2O are not strong enough to replace the ______ between the H2O molecules.
Dipole-induced dipole; hydrogen bonding.
What is the equation for parts by mass?
Mass of solute/mass of solution.
What is the equation for mole fraction?
Moles of solute (or solvent)/total moles of solution.
What is the equation for molality?
Moles of solute/kg of solvent.
What is the equation for molarity?
Moles of solute/liters of solution.
Most solids are _____ soluble in a particular solvent at higher temperatures than at lower temperatures, although there are some exceptions. The solubility of a gas in water will generally _____ as temperature increases.
More; decrease (fill-in-the-blanks).
Colligative properties are properties of a solution that depend only on the ______ of solute particles in a given volume of solution, not on their ______.
Number; type (fill-in-the-blanks).
How does the addition of phosphorus to silicon (a.k.a doping) create an n-type semiconductor?
The extra electrons from the phosphorus atoms bridge the gap between the valence and conductance bands, increasing the conductivity.
Which type of unit cell has atoms in the corners of their cube formation, and one in the centre of each face of the cube?
The face-centered unit cell (definition).
Identical particles lie at each corner and in the center of each face but not in the center of the cube in what cell type?
The face-centered unit cell (identical particles).
What is a unit cell?
The smallest group of particles within a crystal that retains the geometric shape of the crystal.
What is occurring from E to F on the heating curve?
The substance is in a gaseous state; The particles are far apart and movement dominates the phase.
What is occurring from C to D on the heating curve?
The substance is in the liquid phase; the kinetic energy of the liquid particles is increasing.
What is occurring from D to E on the heating curve?
The substance is transitioning from a liquid to a gas (vaporization); both states are present.
What is occurring from B to C on the heating curve?
The substance is transitioning from a solid to a liquid (fusion); both states are present.