Gen Chem #3 Exam

Spontaneous reaction

occurs naturally in a system without the need for external energy

Informal Def. Entropy

Entropy is a measure of disorder or randomnes

Formal def. entropy

measures the number of ways a system can be arranged.

State of a system

a system in which it is determined by time

The speed of a process is determined by: .
5) The spontaneity of a process is determined by:

a) kinetics

b.) thermodynamics

Voltaic cells

: A battery where a spontaneous redox reaction produces electricity.

Half cell

One part of a voltaic cell where either oxidation or reduction occurs.

: Which direction do electrons flow in a voltaic cell?

from anode to cathode.

What does a Salt Bridge do?

It allows ion flow to balance charge

What is an Ampere (A)?

A unit of electric current (rate of electron flow)

What is a Volt (V)?

A unit of electric potential – how strongly electrons are pushed through the circuit.

Redox Reactions

a type of chemical reaction where electrons are transferred between substances.

standard state for gas

one bar

standard state for solids and liquids

1 atm

standard state for pure subsnaces

1 M

what is a system

what is a surrounding

a system refers to the specific part of the universe that is being studied, while the surroundings compasses everything else around the universe

second and third law of thermodunapics

What is the 2nd law of thermodynamics?
A: The entropy of an isolated system always increases or remains constant; it never decreases.

What is the 3rd law of thermodynamics?
A: The entropy of a perfect crystal is zero at absolute zero temperature (0 K).

standard molar entrpoies

the entropy of one mole of a substance in its standard state one atm