67 Questions
Which of the following is true about colligative properties?
The relative number of solute molecules in the solution and nature of the solvent affect colligative properties
According to Raoult’s law, what does the relative lowering of saturated vapour pressure depend on for a dilute solution?
The relative lowering of saturated vapour pressure is equal to the mole fraction of the solute
What does the vapour pressure of the solvent above the solution depend on?
Mole fraction of the solvent
Which statement correctly describes the freezing point of the solution (Tf)?
Separation of the first crystal of the solvent takes place
Which of the following best describes the boiling point of a solution?
It is always higher than that of the pure solvent
What determines the osmotic pressure of a solution?
The number of particles in the solution
What is the characteristic of Kb (the molar boiling point elevation constant)?
Solvent
What happens to osmotic pressure when the temperature decreases?
Decreases
What type of solution has a lower osmotic pressure than a reference solution?
Hypotonic solution
Which solution has the higher osmotic pressure among the options?
1M NaCl
What is the osmotic pressure of a 0.1 M nonelectrolyte solution at 0°C?
2.24 atm
Which statement is correct for Vant Hoff’s law?
The osmotic pressure (π) of a solution is the pressure required to increase osmosis from pure solvent into the solution.
Which expressions are used for determination of molar concentration?
1,3,5
What is correct for determination of a molar mass of a substance?
M = rac{ riangle Tf imes m_{solvent}}{m_{solute}}
What is the boiling point (Tb) of a 1M glucose solution?
100.520C
What is the freezing point (Tf) of a 1M glucose solution?
-1.860C
Which statement about ionic strength is correct?
Al(NO3)3 has the highest ionic strength among equimolar solutions.
Which species has the highest activity factor for K+ ions?
K3PO4
According to Lewis concept, which statement is true about acids?
An acid is a substance that donates a lone pair of electrons.
Which statement regarding Ostwald's dilution law is correct?
The correct expression for Ostwald's dilution law is K = Cα2.
Among the given equimolar solutions, which one has the lowest ionic strength?
Na3PO4
Which statement about the activity factor of NO3 - ions is correct?
The activity factor of NO3 - ions is lowest in Al(NO3)3.
Which compound has the highest ionic strength among ZnSO4, Na2SO4, and NaCl?
Fe2(SO4)3
According to Bronsted-Lowry concept, what happens to the conjugate base as the acid gets stronger?
The conjugate base becomes stronger.
Which solvents have a leveling effect on acids?
Solvents with lower affinity towards protons.
Which equation is used to determine the ionic strength for strong electrolytes?
I = 1/2 Σcz2
Which type of system does not allow transfer of matter but allows transfer of energy to and from surroundings?
Closed system
Which of the following is an example of a state function?
Entropy
What is the equation for entropy change (ΔS) in terms of the entropy change of the system (ΔSsys) and the entropy change of the surroundings (ΔSsurr)?
ΔS = ΔSsys + ΔSsurr
What is the criteria for spontaneity of a reaction?
ΔG < 0
Which thermodynamic potential measures the maximum reversible work that can be done by a system at constant temperature and pressure?
Gibbs free energy (G)
What is the equation for Gibbs free energy change (ΔG) for a reaction?
ΔG = ΔH - TΔS
For which type of reaction does the heat released have a negative value?
Exothermic reaction
What type of reaction absorbs energy from its surroundings?
Endothermic reaction
Which law deals with the relationship between heat changes that occur during a series of reactions?
Hess's law
What does the change in Gibbs free energy (ΔG) for a reaction represent?
The maximum reversible work that can be done by the reaction at constant temperature and pressure
What quantity is independent of the path taken to reach that state?
State functions
What potential measures the disorder or randomness of a system?
Entropy (S)
Which of the following factors does NOT affect the dissociation constant (K) of a weak electrolyte?
The osmotic pressure of the solution
Which of the following statements about the dissociation degree of a weak electrolyte (α) is correct?
“α” increases by dilution of water solution
When NH4Cl is added to a solution of NH4OH, what happens to the concentration of OH–?
Concentration of OH– decreases
Which factor does NOT practically affect the dissociation degree of acetic acid in an aqueous solution?
Raising the temperature
Which equation is correct for polyprotic acids?
Ka total=K1+K2+K3
Which expressions are correct for the relationship between Ka, Kb, and Kw?
pKa · pKb = 14
Which expressions are correct for Kw, [H+], and [OH–]?
-lgKw = (–lg[H+] ) – (–lg[OH–] )
If Ka for an acid is 10–5, what is the pKb value of its conjugate base?
9
If pKa values of four acids at 25°C are given below, what is the pKa of the strongest acid?
2
[OH–] ion concentration in a solution is 10^–4, what is the pH of the solution?
12
If the pH of a solution is 4 and it increases up to 5, what should be the change in the H+ ion concentration?
Halved
What is the equation for calculating pH of a weak acid solution?
pH = 14 − 1/2 (pKa + lgCa)
What type of system allows transfer of neither matter nor energy to and from its surroundings?
None of the above
Which of the following is an example of a closed system?
Some amount of water present in equilibrium with its vapor in a closed and insulated beaker
Which type of system is the human body an example of?
An open system
Which of the following are state functions?
1, 3, 4
What is a thermodynamic state function?
A quantity the value of which is independent on the path
Which of the following is not a state function?
q + w
According to Hess's law, the thermal effects of a reaction depend on...
initial and final conditions of the reacting substances
Enthalpy changes of a reaction depend on...
2, 3, 4
The enthalpy change of a reaction does not depend on the...
the number of intermediate steps for converting reactants into products
The enthalpies of the elements in their standard states are...
zero at 298 K
The enthalpy of formation of a compound from the elements ...
is either positive or negative
The heat of neutralization is constant when dilute solution of...
strong acid and strong base react
Which of the following neutralization reactions have the highest neutralization heat?
NH4OH and HCl
Which of the following is NOT correct?
The free energy of a system in any spontaneous process tends to decrease
When ice melts into water, entropy…
increases
Which of the following expressions is correct?
$1/2 P P nRTln ΔS=$
What happens to the concentration of OH– when NH4Cl is added to a solution of NH4OH?
Decreases
Study Notes
- A closed system is a system where transfer of matter is not possible, but transfer of energy to and from surroundings ispossible.
- Examples of closed systems: some amount of hot water enclosed in a closed container.
- Human body is an example of an open system, as it exchanges matter with the environment.
- State functions are thermodynamic potentials that only depend on the current state of a system and not on the path taken to reach that state.
- Examples of state functions: internal energy (ΔE), entropy (S), and enthalpy (H).
- A thermodynamic state function is a quantity whose value is independent of the path taken to reach that state.
- Heat of compound formation is the heat absorbed or released when one mole of a compound is formed from its elements in their standard states.
- Enthalpy changes of a reaction depend on the conditions of the reaction, initial and final concentration, and the physical state of reactants and products.
- For an exothermic reaction, the heat released is a negative value.
- Entropy is a measure of disorder and increases when a system undergoes a spontaneous change.
- The Gibbs free energy (G) is a thermodynamic potential that measures the maximum reversible work that can be done by a system at constant temperature and pressure.
- An endothermic reaction is a reaction that absorbs energy from its surroundings, and for it to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- The criteria for spontaneity of a reaction: ΔG < 0.
- Gibbs free energy, enthalpy, and entropy are related through the legacy of Gibbs, specifically through the equation G = H - TS.
- Gibbs free energy is the maximum reversible work that can be done by a system at constant temperature and pressure.
- For an endothermic reaction to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- Internal energy (ΔE) is a state function that measures the maximum reversible work that can be done by a system at constant temperature and volume.
- Enthalpy (H) is a thermodynamic potential that measures the maximum reversible work that can be done by a system at constant temperature and pressure.
- Entropy (S) is a thermodynamic potential that measures the disorder or randomness of a system.
- Hess's law deals with the relationship between heat changes that occur during a series of reactions.
- The thermal effects of a reaction depend on the initial and final conditions of the reacting substances.
- Enthalpy changes of a reaction are independent of the number of intermediate steps involved in the reaction.
- Heat of compound formation is the heat absorbed or released when one mole of a compound is formed from its elements in their standard states.
- The enthalpy change of a reaction is the difference in enthalpy between the reactants and the products.
- The heat of neutralization is the heat absorbed or released when an acid and a base react to form a salt and water.
- The heat of neutralization is constant for dilute solutions of strong acids and strong bases.
- When ice melts, the entropy increases due to the increase in the number of translationally disordered water molecules.
- The equation for entropy change (ΔS) in terms of the entropy change of the system (ΔSsys) and the entropy change of the surroundings (ΔSsurr) is: ΔS = ΔSsys + ΔSsurr > 0.
- The Gibbs free energy change (ΔG) for a reaction is given by the equation: ΔG = ΔH - TΔS.
- For a spontaneous reaction, ΔG is negative, which means that the enthalpy change is less than the product of the temperature (T) and entropy change (ΔS) of the reaction.
- The criteria for spontaneity of a reaction are: ΔG < 0.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The change in Gibbs free energy (ΔG) for a reaction is given by the equation: ΔG = ΔH - TΔS.
- For a reaction to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- The Gibbs free energy change (ΔG) is a thermodynamic potential that measures the maximum reversible work that can be done by a system at constant temperature and pressure.
- The change in Gibbs free energy (ΔG) for a reaction is the difference between the enthalpy change (ΔH) and the product of the temperature (T) and entropy change (ΔS) of the reaction.
- For an endothermic reaction to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- The Gibbs free energy change (ΔG) is a thermodynamic potential that measures the maximum reversible work that can be done by a system at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for an endothermic reaction to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- The Gibbs free energy change (ΔG) for a reaction is given by the equation: ΔG = ΔH - TΔS.
- For an endothermic reaction to proceed spontaneously, the entropy change (ΔS) must be positive and greater than the enthalpy change (ΔH).
- The change in Gibbs free energy (ΔG) for a reaction is the difference between the enthalpy change (ΔH) and the product of the temperature (T) and entropy change (ΔS) of the reaction.
- The Gibbs free energy change (ΔG) is a thermodynamic potential that measures the maximum reversible work that can be done by a system at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work that can be done by the reaction at constant temperature and pressure.
- The Gibbs free energy change (ΔG) for a reaction is a measure of the maximum reversible work
Test your knowledge of weak electrolyte dissociation with this quiz. Answer questions about factors affecting dissociation constant (K) and the dissociation degree (α) of weak electrolytes.
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