Properties of Matter Quiz

Which of the following properties are extensive (choose all that apply):

• Temperature

• number of moles

• energy

• amount of heat released

• mass

A piston containing an ideal gas expands isothermally from 7 atm pressure to 2 atm pressure. The energy of the system (that is, the contents of the piston) remains constant during this process.

• True

• False

The enthalpy change for a process is equal to the heat transferred to the system under which of the following conditions?

• constant volume

• constant pressure

• constant temperature

• reversible expansion

• expansion at a constant pressure followed by reversible compression

Energy is a good indicator of the direction of spontaneous change for macroscopic mechanical objects but not for molecular processes.

• True

• False

Which of the following statements about potential energy is true?

• The potential energy of an ideal gas is equal to its kinetic energy.

• The potential energy of an atom is the work done in moving the atom from infinity to its present position.

• Potential energy is always absolutely conserved.

• The potential energy of a system always increases.

• Potential energy is an intensive function.

A reaction that releases energy is called an ________ reaction.

• exothermic

• endothermic

• neutral

• isothermal

Electrostatic interactions are governed by ________'s law.

• Coulomb

• Newton

• Ohm

• Faraday

The energy for van der Waals interactions approaches _____ as the distance between atoms goes to zero and approaches _____ at infinite distance.

• infinity, zero

• zero, infinity

• negative infinity, infinity

• infinity, negative infinity

One mole of an ideal monatomic gas is initially at 300 K and 1010 J•L⁻¹ pressure inside a cylinder with a frictionless piston. The cylinder is an isolated (adiabatic) system. The gas expands against zero external pressure. When the volume expands to 24.7 L, a peg stops the piston. Calculate ΔU (the change in energy), q (the heat transferred to the system), and w (the work done by the system) when the expansion is isothermal and reversible.

• ΔU = 0, q = 0, w = 0

• ΔU = 0, q = 1010 J, w = -1010 J

• ΔU = -1010 J, q = 0, w = 1010 J

• ΔU = 1010 J, q = -1010 J, w = 0

One mole of a different ideal monatomic gas is initially at 300 K and 1010 J•L⁻¹ pressure inside a cylinder with a frictionless piston. Calculate ΔU (the change in energy), q (the heat transferred to the system), and w (the work done on the system) when the expansion is isothermal and against a constant pressure of 101 J•L⁻¹.

• ΔU = 0, q = -2244 J, w = 2244 J

• ΔU = 0, q = 2244 J, w = -2244 J

• ΔU = 2244 J, q = 3254 J, w = -1010 J

• ΔU = 2244 J, q = -1010 J, w = 3254 J