CHEM-1770 CHPT.9 Thermochemistry

What is the first law of Thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another. This principle is often expressed as the conservation of energy.

What is “delta” E of the universe?

The change in internal energy of the universe, which is equal to the energy added to the system minus the energy lost by the system.

What is “State Function”?

A property that depends only on the current state of a system, regardless of the path taken to reach that state. Examples include temperature, pressure, and volume.

What is “Path Function”?

A property that depends on the specific path taken during a process, unlike state functions. Examples include heat and work.

What is “Work”?

The energy transfer that occurs when a force is applied to an object, causing it to move in the direction of the force.

What is “Heat”?

The energy transferred between systems or objects with different temperatures, flowing from hot to cold until thermal equilibrium is reached.

What is “Endothermic Process”?

A process that absorbs heat from its surroundings, resulting in a decrease in the temperature of the surroundings.

What is “Exothermic process”?

A process that releases heat to its surroundings, leading to an increase in the temperature of the surroundings.

What is “Endoergic process?”

A process that absorbs energy, often in the form of heat, from the surroundings to proceed. Work is done on the system by the surroundings.

What is “Exoergic process”?

Work is done by the system on the surroundings.

What is “Energy”?

the ability to do work or to transfer heat.

What is “Internal energy”?

The combined kinetic and potential energies of atoms and/or molecule that make up an object or system.

What is “Potential energy”?

Associated with the relative position of an object.

What is “Kinetic energy”?

Associated with motion.

What is “force”?

m X a

What is a “Joule"?

1 kg m²/s²

What is “System”?

The part of the universe being considered.

What is “Surroundings”?

The remainder of the universe.

What is “Universe”?

System + Surroundings

Which function is “Energy”?

a state function

Which function is “Heat”?

Path Function

Which function is “Work”?

Path function

What does Δ (delta) mean?

“change in”, defined as the difference in the final and inital states and is only applicable to state functions.

What is the sign convention for - q(heat)?

system loses thermal energy

what is the sign convention for + q(heat)?

system gains thermal energy

what is the sign convention for + w(work)?

work done on the system

what is the sign convention for -w(work)?

work done by the system

what does +ΔE (change in internal energy)

energy flows into the system

what is the sign convention for -ΔE(change in internal energy)

energy flows out of the system

What is Enthalpy?

heat gained or lost by the system at constant pressure,calculated by measuring the temperatrue change in the surroundings.

What is heat formation?

the heat of reaction for the formation of one

mole of a substance from the elements in their standard state.