Exam 3 Flashcards
(27 cards)
Which of these statements about the common-ion effect is most correct?
The solubility of a salt MA is decreased in a solution that already contains either M+ or A-
Consider the equilibrium:
B(aq)+H20(l) HB+(aq) + OH-(aq)
Suppose that a salt of HB+ is added to a solution of B at equilibrium
The concentration of B(aq) will increase
What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?
The concentration of fluoride ion will decrease and the concentration of hydrogen fluoride will increase
The Henderson-Hasselbalch equation is
pH=pKa+ log [base]/[acid]
The addition of hydrofluoric acid and ___ to water produces a buffer solution
NaF
In a solution, when the concentrations of a weak acid and its conjugate base are equal….
The -log of the [H+] and the -log of the Ka are equal
Which below best describes the behavior of an amphoteric hydroxide in water?
With both conc. aq. NaOH and conc. aq HCL, its suspension dissolves
In nonaqueous solvents, it is possible to react HF to create H2F+. Which of these statements follows from this observation
HF can act like a base in nonaqueous solvents
There is an acid in the nonaqueous meduium that is a stronger acid than HF
Under what conditions does an ionic compound precipitate from a solution of the constituent ions?
When Q exceeds Ksp
The first law of thermodynamics can be given as
Delta E= q+w
A reversible change produces the maximum amount of ___ that can be achieved by the system on the surroundings
Work
A reaction that is spontaneous
Will proceed without outside intervention
Of the following only ___ is not a state function
q
When a system is at equilibrium
The process is not spontaneous in either direction
A reversible process is one that
can be reversed with no net change in either system or surroundings
Which of the following statements is true?
Spontaneity can depend on the temperature
The process of iron being oxidized to make iron (III) oxide (rust) is spontaneous. Which of these statements about this process is true?
Equlibrium is achieved in a closed system when the rate of iron oxidation is equal to the rate of iron (III) oxide reduction
The thermodynamic quantity that expresses the extent of randomness in a system is __
Entropy
For an isothermal process, delta S=
qrev/T
Which one of the following is always positive when a spontaneous process occurs?
delta Suniverse
The second law of thermodynamics states that
For any spontaneous process, the entropy of the universe increases
In a particular spontaneous process the entropy of the system decreases. What can you conclude about the sign and magnitude of delta S surr?
Delta Ssurr. is positive and greater than the magnitude of the decrease in delta Ssys
Which one of the following processes produces a decrease in the entropy of the system?
Deposition of solid CO2 from gaseous CO2
Which one of the following processes produces a decrease of the entropy of a system?
Dissolving oxygen in water
