Chem 120: Lindahl Exam 1-7
True or False Questions
Exam 1 A - answers-
In a population of molecules in a liquid at room temperature, some molecules will have
greater kinetic energy than others. - answers-True
If heat is released from the system (at constant pressure) when a reaction
occurs, Delta Hren will be a positive number. - answers-False
The ideal van’s Hoff factor for Pb(NO3)2 should be 2. - answers-False
When solid ionic salts are dissolved in water, the system always absorbs
energy from the surrounding. - answers-False
The boiling point of a liquid (at sea level) is the temperature at which the vapor pressure
equals 1 atm. - answers-True
Henry's Law states that when a solute is added to a solvent, the vapor
pressure of the solvent will decline in proportion to the mole fraction of the solvent -
answers-False
The unit cell of NaCl contains 4 Na+ ions - answers-True
Exam 1 B - answers-
In a closed system, molecules are removed from the system during the process of
evaporation - answers-False
The equilibrium vapor pressure of a liquid is the same at all temperatures. - answers-
False
, Energy is released into the surroundings when gaseous ions in a chemical system
become hydrated - answers-True
Activity coefficients range from 0 to 1 - answers-True
The freezing point of a liquid (at sea level) is the temperature at which the
vapor pressure equals 1 atm - answers-False
During the heating of liquid, the temperature continues to climb immediately after the
liquid starts to boil. - answers-False
The ideal van’s Hoff factor for Sr(acetate)2 in water is I = 3. - answers-True
Exam 2 A - answers-
Catalysts speed up reactions by increasing the energy of activation - answers-False
For extremely fast reactions, the activation energy is often negative - answers-False
Exam 2B - answers-
According to the collision theory of kinetics, the rate of a reaction is proportional to the
number of collisions per unit time. - answers-True
The activation energy of a reaction declines as temperature increases - answers-False
A catalyst speeds-up a reaction but it cannot participate in mechanism of the reaction -
answers-False
Exam 3A - answers-
Kc is unitless because it is defined using activities not concentrations. - answers-True
When you reverse or "flip" a reaction, Keq for the resulting reaction is the negative of
the original Keq - answers-False
If Q < Keq for a reversible reaction, the reaction will shift toward products if allowed to
reach equilibrium. - answers-True
For the reaction 2NO (gas) ⇄ N2O2 (gas), Kpa will be unitless. - answers-True
A reversible reaction is at equilibrium when forward and reverse rates are equal -
answers-True
Exam 3B - answers-
True or False Questions
Exam 1 A - answers-
In a population of molecules in a liquid at room temperature, some molecules will have
greater kinetic energy than others. - answers-True
If heat is released from the system (at constant pressure) when a reaction
occurs, Delta Hren will be a positive number. - answers-False
The ideal van’s Hoff factor for Pb(NO3)2 should be 2. - answers-False
When solid ionic salts are dissolved in water, the system always absorbs
energy from the surrounding. - answers-False
The boiling point of a liquid (at sea level) is the temperature at which the vapor pressure
equals 1 atm. - answers-True
Henry's Law states that when a solute is added to a solvent, the vapor
pressure of the solvent will decline in proportion to the mole fraction of the solvent -
answers-False
The unit cell of NaCl contains 4 Na+ ions - answers-True
Exam 1 B - answers-
In a closed system, molecules are removed from the system during the process of
evaporation - answers-False
The equilibrium vapor pressure of a liquid is the same at all temperatures. - answers-
False
, Energy is released into the surroundings when gaseous ions in a chemical system
become hydrated - answers-True
Activity coefficients range from 0 to 1 - answers-True
The freezing point of a liquid (at sea level) is the temperature at which the
vapor pressure equals 1 atm - answers-False
During the heating of liquid, the temperature continues to climb immediately after the
liquid starts to boil. - answers-False
The ideal van’s Hoff factor for Sr(acetate)2 in water is I = 3. - answers-True
Exam 2 A - answers-
Catalysts speed up reactions by increasing the energy of activation - answers-False
For extremely fast reactions, the activation energy is often negative - answers-False
Exam 2B - answers-
According to the collision theory of kinetics, the rate of a reaction is proportional to the
number of collisions per unit time. - answers-True
The activation energy of a reaction declines as temperature increases - answers-False
A catalyst speeds-up a reaction but it cannot participate in mechanism of the reaction -
answers-False
Exam 3A - answers-
Kc is unitless because it is defined using activities not concentrations. - answers-True
When you reverse or "flip" a reaction, Keq for the resulting reaction is the negative of
the original Keq - answers-False
If Q < Keq for a reversible reaction, the reaction will shift toward products if allowed to
reach equilibrium. - answers-True
For the reaction 2NO (gas) ⇄ N2O2 (gas), Kpa will be unitless. - answers-True
A reversible reaction is at equilibrium when forward and reverse rates are equal -
answers-True
Exam 3B - answers-
