GEN CHEM 162 EXAM 1 QUESTIONS
AND ANSWERS
Solution - Correct Answers -a homogeneous mixture (uniform and consistent
composition throughout the sample) composed of solute(s) dissolved in a solvent
Solubility - Correct Answers -Amount of a substance (solute) that dissolves in another
(solvent)
Soluble - Correct Answers -When one substance (solute) dissolves in another (solvent)
Ex: NaCl in water
Miscible - Correct Answers -Describes two liquids that are soluble in each other (a
solute liquid dissolves in solvent liquid)
Insoluble - Correct Answers -When one substance (solute) doesn't dissolve in another
(solvent)
Ex: Oil in water (creates two distinct layers)
Common polar solvents - Correct Answers -Water (H2O)
Acetone (CH3COCH3)
Methanol (CH3OH)
Ethanol (CH3CH2OH)
Common nonpolar solvents - Correct Answers -Hexane (C6H14)
Diethyl ether (CH3CH2OCH2CH3)
Toluene (C7H8)
Carbon tetrachloride (CCl4)
Polarity phrase for solutions - Correct Answers -"like dissolves like"
Entropy - Correct Answers -A measure of how much of energy of a system is
dispersed/randomized (energy of disorder)
What will happen anytime the energy of a system can spread out - Correct Answers -it
will automatically spread out on its own (because it increases entropy)
Elementary Reaction - Correct Answers -a single reaction that cannot be broken down
into simpler steps
, Two Requirements of Plausible Mechanism - Correct Answers -1. When summed, the
individual steps of the mechanism must add up to overall balanced reaction
2. The mechanism must account for the experimentally determined rate law of the
overall reaction
Molecularity - Correct Answers -the number of reactant particles involved in an
elementary step
Three steps to forming a solution - Correct Answers -1. Separate solute particles from
each other by breaking solute-solute interactions (endothermic)
2. Separate solvents by breaking solvent-solvent interactions (endothermic)
3. Let solute and solvent particles interact with each other to make solute-solvent
interactions (exothermic)
ΔH solution= - Correct Answers -ΔHsolute + ΔHsolvent + ΔHmix
ΔHhydration= - Correct Answers -ΔHsolvent + ΔHmix
ΔHhydration is (-) because ΔHmix is highly exothermic and makes up for the
endothermic of ΔHsolvent
Saturated Solution - Correct Answers -A solution in which no additional solute can be
dissolved (Solvent has dissolved all solute that it can)
Unsaturated Solution - Correct Answers -A solution in which more solute can dissolve
Supersaturated Solution - Correct Answers -A solution that contains more than the
equilibrium amount of solute --> very unstable solution in which precipitate forms
Temperature impact on solid solutes - Correct Answers -Solid solutes tend to be MORE
soluble under HIGHER TEMPERATURES
Temperature impact on gaseous solutes - Correct Answers -Gaseous solutes tend to be
LESS soluble under HIGHER TEMPERATURES
Ex: pouring a cold soda compared to warm soda (warm soda has more bubbles)
Pressure impact on solubility of solutes - Correct Answers -Solid solutes: no impact
Gas solutes: as PRESSURE INCREASES, SOLUBILITY INCREASES
Molarity (M) - Correct Answers -moles of solute/liters of solution
Molality (m) - Correct Answers -moles of solute/kg of solvent
Colligative Properties - Correct Answers -Physical properties of a solution that only
depend on the number of particles dissolved in a solution (properties change depending
on amount of solute dissolved, but identity of solute has no effect)
AND ANSWERS
Solution - Correct Answers -a homogeneous mixture (uniform and consistent
composition throughout the sample) composed of solute(s) dissolved in a solvent
Solubility - Correct Answers -Amount of a substance (solute) that dissolves in another
(solvent)
Soluble - Correct Answers -When one substance (solute) dissolves in another (solvent)
Ex: NaCl in water
Miscible - Correct Answers -Describes two liquids that are soluble in each other (a
solute liquid dissolves in solvent liquid)
Insoluble - Correct Answers -When one substance (solute) doesn't dissolve in another
(solvent)
Ex: Oil in water (creates two distinct layers)
Common polar solvents - Correct Answers -Water (H2O)
Acetone (CH3COCH3)
Methanol (CH3OH)
Ethanol (CH3CH2OH)
Common nonpolar solvents - Correct Answers -Hexane (C6H14)
Diethyl ether (CH3CH2OCH2CH3)
Toluene (C7H8)
Carbon tetrachloride (CCl4)
Polarity phrase for solutions - Correct Answers -"like dissolves like"
Entropy - Correct Answers -A measure of how much of energy of a system is
dispersed/randomized (energy of disorder)
What will happen anytime the energy of a system can spread out - Correct Answers -it
will automatically spread out on its own (because it increases entropy)
Elementary Reaction - Correct Answers -a single reaction that cannot be broken down
into simpler steps
, Two Requirements of Plausible Mechanism - Correct Answers -1. When summed, the
individual steps of the mechanism must add up to overall balanced reaction
2. The mechanism must account for the experimentally determined rate law of the
overall reaction
Molecularity - Correct Answers -the number of reactant particles involved in an
elementary step
Three steps to forming a solution - Correct Answers -1. Separate solute particles from
each other by breaking solute-solute interactions (endothermic)
2. Separate solvents by breaking solvent-solvent interactions (endothermic)
3. Let solute and solvent particles interact with each other to make solute-solvent
interactions (exothermic)
ΔH solution= - Correct Answers -ΔHsolute + ΔHsolvent + ΔHmix
ΔHhydration= - Correct Answers -ΔHsolvent + ΔHmix
ΔHhydration is (-) because ΔHmix is highly exothermic and makes up for the
endothermic of ΔHsolvent
Saturated Solution - Correct Answers -A solution in which no additional solute can be
dissolved (Solvent has dissolved all solute that it can)
Unsaturated Solution - Correct Answers -A solution in which more solute can dissolve
Supersaturated Solution - Correct Answers -A solution that contains more than the
equilibrium amount of solute --> very unstable solution in which precipitate forms
Temperature impact on solid solutes - Correct Answers -Solid solutes tend to be MORE
soluble under HIGHER TEMPERATURES
Temperature impact on gaseous solutes - Correct Answers -Gaseous solutes tend to be
LESS soluble under HIGHER TEMPERATURES
Ex: pouring a cold soda compared to warm soda (warm soda has more bubbles)
Pressure impact on solubility of solutes - Correct Answers -Solid solutes: no impact
Gas solutes: as PRESSURE INCREASES, SOLUBILITY INCREASES
Molarity (M) - Correct Answers -moles of solute/liters of solution
Molality (m) - Correct Answers -moles of solute/kg of solvent
Colligative Properties - Correct Answers -Physical properties of a solution that only
depend on the number of particles dissolved in a solution (properties change depending
on amount of solute dissolved, but identity of solute has no effect)
