Chem 162 - Quiz 4
What is a solute? - CORRECT ANSWER-the substance that is dissolved
What is a solvent? - CORRECT ANSWER-the substance in which the solute
dissolves
Usually, is there more solvent or solute present in a solution? - CORRECT
ANSWER-solvent
When determining the enthalpy of solution, is deltaH1 and deltaH2 endothermic
or exothermic? - CORRECT ANSWER-endothermic
Why are deltaH1 and deltaH2 endothermic processes? - CORRECT
ANSWER-the attractive forces between particles must be overcome to expand
solute and solvent
What type of process is deltaH3 in finding deltaHsoln? - CORRECT
ANSWER-exothermic
Why is deltaH3 an exothermic process? - CORRECT ANSWER-attractive forces
between solute and solvent particles cause them to come together and stabilize
What determines if the enthalpy of solution is exothermic or endothermic? -
CORRECT ANSWER-relative magnitudes during the process
What is the equation for the enthalpy of solution? - CORRECT
ANSWER-deltaH(sol) = deltaH(1) + deltaH(2) + deltaH(3)
What is the relationship between endothermic deltaH(sol) and IMFs when finding
a positive deltaH(sol)? - CORRECT ANSWER-an endothermic process means
there needs to be very different IMF strengths because the energy needed in
deltaH(3) to stabilize the solution will not be as great as the energy put in to
break the solute and solvent
What is the equation for enthalpy of solution for an ionic solute in water? -
CORRECT ANSWER-deltaH(sol) = deltaH(L) + deltaH(hyd)
, What types of solutes do polar solvents dissolve best? - CORRECT
ANSWER-Polar and ionic
What types of solutes do nonpolar solvents dissolve best? - CORRECT
ANSWER-nonpolar
What conclusions can be drawn about positive entropy of solution? - CORRECT
ANSWER-increase in disorder, increase in the degrees of freedom available for
molecules
What contributes to a negative entropy of solution? - CORRECT
ANSWER-mixture of polar and nonpolar solutions, a solvent cage forming, more
order in the solvent than in the solute
What does Henry's Law state? - CORRECT ANSWER-the solubility of a gas in a
liquid is directly proportional to the partial pressure of that gas on the surface of
the liquid
What is the relationship between kH and partial pressure? - CORRECT
ANSWER-the smaller the kH the higher the partial pressure of the gas to get a
given solubility
Why does increasing temperature decrease solubility for gases dissolving in
liquid water? - CORRECT ANSWER-As the temp of the solution increases, the
kinetic energy of particles increases which leads to more gas forming
How does temperature impact solids dissolving in liquid water? - CORRECT
ANSWER-Increase in temp. leads to faster dissolving of the solid
What are the units for molality? - CORRECT ANSWER-(moles of solute)/(kg of
solvent)
What are colligative properties? - CORRECT ANSWER-properties that depend
on the # of solute particles, but not on the type
What is a solute? - CORRECT ANSWER-the substance that is dissolved
What is a solvent? - CORRECT ANSWER-the substance in which the solute
dissolves
Usually, is there more solvent or solute present in a solution? - CORRECT
ANSWER-solvent
When determining the enthalpy of solution, is deltaH1 and deltaH2 endothermic
or exothermic? - CORRECT ANSWER-endothermic
Why are deltaH1 and deltaH2 endothermic processes? - CORRECT
ANSWER-the attractive forces between particles must be overcome to expand
solute and solvent
What type of process is deltaH3 in finding deltaHsoln? - CORRECT
ANSWER-exothermic
Why is deltaH3 an exothermic process? - CORRECT ANSWER-attractive forces
between solute and solvent particles cause them to come together and stabilize
What determines if the enthalpy of solution is exothermic or endothermic? -
CORRECT ANSWER-relative magnitudes during the process
What is the equation for the enthalpy of solution? - CORRECT
ANSWER-deltaH(sol) = deltaH(1) + deltaH(2) + deltaH(3)
What is the relationship between endothermic deltaH(sol) and IMFs when finding
a positive deltaH(sol)? - CORRECT ANSWER-an endothermic process means
there needs to be very different IMF strengths because the energy needed in
deltaH(3) to stabilize the solution will not be as great as the energy put in to
break the solute and solvent
What is the equation for enthalpy of solution for an ionic solute in water? -
CORRECT ANSWER-deltaH(sol) = deltaH(L) + deltaH(hyd)
, What types of solutes do polar solvents dissolve best? - CORRECT
ANSWER-Polar and ionic
What types of solutes do nonpolar solvents dissolve best? - CORRECT
ANSWER-nonpolar
What conclusions can be drawn about positive entropy of solution? - CORRECT
ANSWER-increase in disorder, increase in the degrees of freedom available for
molecules
What contributes to a negative entropy of solution? - CORRECT
ANSWER-mixture of polar and nonpolar solutions, a solvent cage forming, more
order in the solvent than in the solute
What does Henry's Law state? - CORRECT ANSWER-the solubility of a gas in a
liquid is directly proportional to the partial pressure of that gas on the surface of
the liquid
What is the relationship between kH and partial pressure? - CORRECT
ANSWER-the smaller the kH the higher the partial pressure of the gas to get a
given solubility
Why does increasing temperature decrease solubility for gases dissolving in
liquid water? - CORRECT ANSWER-As the temp of the solution increases, the
kinetic energy of particles increases which leads to more gas forming
How does temperature impact solids dissolving in liquid water? - CORRECT
ANSWER-Increase in temp. leads to faster dissolving of the solid
What are the units for molality? - CORRECT ANSWER-(moles of solute)/(kg of
solvent)
What are colligative properties? - CORRECT ANSWER-properties that depend
on the # of solute particles, but not on the type
