CHEM113: SB 15.1-15.2

Which of the following statements correctly reflect the relationship between the spontaneity of a reaction and the sign of ΔH? Select all that apply. - The spontaneity of a process is easily determined from the sign of ΔH for the reaction. - All endothermic processes are nonspontaneous. - A negative value of ΔH favors spontaneity. - The sign of ΔH alone is not sufficient evidence to determine the spontaneity of a process.

- A negative value of ΔH favors spontaneity. - The sign of ΔH alone is not sufficient evidence to determine the spontaneity of a process.

Which of the following familiar processes is/are spontaneous? Select all that apply. - A teaspoon of table salt dissolving in 1 L of boiling water - A ball rolling down a hill - Water decomposing to H2 and O2 at 25oC - Water boiling at 0°C and 1 atm

- A teaspoon of table salt dissolving in 1 L of boiling water - A ball rolling down a hill

Select the statements that correctly describe the microstates of a system, W. Select all that apply. - W is the number of energetically equivalent ways the particles of a system may be arranged. - Entropy increases with the number of microstates. - Increasing the temperature of a system will increase W - W = NX, where N is the number of particles and X is the number of cells they occupy.

- W is the number of energetically equivalent ways the particles of a system may be arranged. - Entropy increases with the number of microstates. - Increasing the temperature of a system will increase W.

Which of the following must be known in order to assess the spontaneity of a chemical reaction or physical process at a particular set of conditions? Select all that apply. Multiple select question.

- change in enthalpy - change in entropy

Two unknown reactions (A and B) are analyzed. It is found that reaction A is exothermic, while reaction B is endothermic. Which of these reactions is spontaneous? - Reaction B is spontaneous because it is endothermic. - Reaction A is spontaneous because it is exothermic. - Spontaneity cannot be determined from the given information.

Spontaneity cannot be determined from the given information.

spontaneous process = vs nonspontaneous process =

Spontaneous process = A process that does occur under a given set of conditions A process that does occur under a given set of conditions Nonspontaneous process = A process that does not occur under a given set of conditions A process that does not occur under a given set of conditions

translational motion of energy = vibrational motion of energy = rotational motion of energy =

Translational = The entire molecule moves through space. The entire molecule moves through space. Vibrational = Atoms in the molecule move relative to one another. Atoms in the molecule move relative to one another. Rotational = Atoms spin about an axis running through the center of mass of the molecule. Atoms spin about an axis running through the center of mass of the molecule.

Mathematically entropy is defined by the equation S = k ln W. W represents the number of possible arrangements, where mathematically W = XN. X represents the number of __________ containing N ______________.

cells molecules, atoms, or particles

In order to assess the spontaneity of a chemical reaction or physical process both the change in ______________ and ______________ associated with the reaction or process must be known.

enthalpy, entropy

The ___________________ of a system is a measure of the ways in which the energy of the system can be dispersed.

entropy

Which of the following types of energy are forms of motional energy? Select all that apply. Multiple select question. - thermal - translational - vibrational - mechanical - rotational

translational vibrational rotational

True or false: If a process occurs spontaneously in one direction under a certain set of conditions, it does not occur spontaneously in the opposite direction under the same conditions.

true Reason: If a process occurs spontaneously in one direction under a certain set of conditions, it is not possible for the process to also occur spontaneously in the opposite direction under the same set of conditions.