Chem 162 - Quiz 4 with 100% Correct
Answers
What is a solute? - ANSWER-the substance that is dissolved
What is a solvent? - ANSWER-the substance in which the solute dissolves
Usually, is there more solvent or solute present in a solution? - ANSWER-solvent
When determining the enthalpy of solution, is deltaH1 and deltaH2 endothermic or
exothermic? - ANSWER-endothermic
Why are deltaH1 and deltaH2 endothermic processes? - ANSWER-the attractive forces
between particles must be overcome to expand solute and solvent
What type of process is deltaH3 in finding deltaHsoln? - ANSWER-exothermic
Why is deltaH3 an exothermic process? - 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? - ANSWER-
relative magnitudes during the process
What is the equation for the enthalpy of solution? - ANSWER-deltaH(sol) = deltaH(1) +
deltaH(2) + deltaH(3)
What is Raoult's Law for solutions with more than one volatile component? - ANSWER-
Psoln = P(A)+P(B) = X(A)P(A) + X(B)P(B)
What are the characteristics for positive deviations from Raoult's Law? - ANSWER-
larger Psoln than expected; weaker interactions between A&B vs. A&A or B&B; easier
to get into vapor phase; mix endothermically --> positive health of solution
What are the characteristics for negative deviations from Raoult's Law? - ANSWER-
smaller Pvap than expected; stronger interaction between A&B vs. A&A or B&B; mix
exothermically --> negative enthalpy of solution
If asked to identify binary liquid systems that would exhibit a positive deviation on a
vapor pressure curve, what do you look for? - ANSWER-Molecules exhibiting similar
interaction strength; look for similar mass
, Why can transition metals show similarity in properties across a period and down a
group? - ANSWER-d and f orbitals don't participate in bonding as readily as s electrons
What are important characteristics about transition metals? - ANSWER-Readily give up
electrons to form cations; good conductors of heat and electricity; malleable and ductile
What rule is responsible for Cr and Cu electron configuration? - ANSWER-Hund's Rule -
orbitals must singly fill the orbitals with parallel spins before going back and filling in the
second space
What allows Cr and Cu to have unexpected filling orders? - ANSWER-The neutral atom
in the gas phase arranges the 4s and 3d orbital on the same level
What are complex ions? - ANSWER-ions formed when a certain number of ligands
bond to a transition metal cation
What is a ligand? - ANSWER-a neutral molecule or ion with a lone pair used to form a
bond to a metal ion
What is the coordination number in tetrahedral or square planar molecules? -
ANSWER-4
What is the coordination number in octahedral molecules? - ANSWER-6
What are coordination compounds? - ANSWER-ionic compounds with a complex ion as
the cation or anion
What is a monodentate ligand? - ANSWER-one electron pair is donated to a transition
metal (TM) cation
What is a bidentate ligand? - ANSWER-two electron pairs to donate
What is a polydentate ligand? - ANSWER-three or more electron pairs to donate
What is the relationship between endothermic deltaH(sol) and IMFs when finding a
positive deltaH(sol)? - 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? - ANSWER-
deltaH(sol) = deltaH(L) + deltaH(hyd)
What types of solutes do polar solvents dissolve best? - ANSWER-Polar and ionic
What types of solutes do nonpolar solvents dissolve best? - ANSWER-nonpolar
Answers
What is a solute? - ANSWER-the substance that is dissolved
What is a solvent? - ANSWER-the substance in which the solute dissolves
Usually, is there more solvent or solute present in a solution? - ANSWER-solvent
When determining the enthalpy of solution, is deltaH1 and deltaH2 endothermic or
exothermic? - ANSWER-endothermic
Why are deltaH1 and deltaH2 endothermic processes? - ANSWER-the attractive forces
between particles must be overcome to expand solute and solvent
What type of process is deltaH3 in finding deltaHsoln? - ANSWER-exothermic
Why is deltaH3 an exothermic process? - 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? - ANSWER-
relative magnitudes during the process
What is the equation for the enthalpy of solution? - ANSWER-deltaH(sol) = deltaH(1) +
deltaH(2) + deltaH(3)
What is Raoult's Law for solutions with more than one volatile component? - ANSWER-
Psoln = P(A)+P(B) = X(A)P(A) + X(B)P(B)
What are the characteristics for positive deviations from Raoult's Law? - ANSWER-
larger Psoln than expected; weaker interactions between A&B vs. A&A or B&B; easier
to get into vapor phase; mix endothermically --> positive health of solution
What are the characteristics for negative deviations from Raoult's Law? - ANSWER-
smaller Pvap than expected; stronger interaction between A&B vs. A&A or B&B; mix
exothermically --> negative enthalpy of solution
If asked to identify binary liquid systems that would exhibit a positive deviation on a
vapor pressure curve, what do you look for? - ANSWER-Molecules exhibiting similar
interaction strength; look for similar mass
, Why can transition metals show similarity in properties across a period and down a
group? - ANSWER-d and f orbitals don't participate in bonding as readily as s electrons
What are important characteristics about transition metals? - ANSWER-Readily give up
electrons to form cations; good conductors of heat and electricity; malleable and ductile
What rule is responsible for Cr and Cu electron configuration? - ANSWER-Hund's Rule -
orbitals must singly fill the orbitals with parallel spins before going back and filling in the
second space
What allows Cr and Cu to have unexpected filling orders? - ANSWER-The neutral atom
in the gas phase arranges the 4s and 3d orbital on the same level
What are complex ions? - ANSWER-ions formed when a certain number of ligands
bond to a transition metal cation
What is a ligand? - ANSWER-a neutral molecule or ion with a lone pair used to form a
bond to a metal ion
What is the coordination number in tetrahedral or square planar molecules? -
ANSWER-4
What is the coordination number in octahedral molecules? - ANSWER-6
What are coordination compounds? - ANSWER-ionic compounds with a complex ion as
the cation or anion
What is a monodentate ligand? - ANSWER-one electron pair is donated to a transition
metal (TM) cation
What is a bidentate ligand? - ANSWER-two electron pairs to donate
What is a polydentate ligand? - ANSWER-three or more electron pairs to donate
What is the relationship between endothermic deltaH(sol) and IMFs when finding a
positive deltaH(sol)? - 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? - ANSWER-
deltaH(sol) = deltaH(L) + deltaH(hyd)
What types of solutes do polar solvents dissolve best? - ANSWER-Polar and ionic
What types of solutes do nonpolar solvents dissolve best? - ANSWER-nonpolar
