R.1.4 Entropy and Spontaneity

Key terms and calculations

Entropy

Measure of the dispersal or distribution of matter and/or energy in a system

Calculating entropy change

Change in entropy = Products - reactants

Gibbs energy must be … in order for a reaction to be spontaneous?

Gibbs energy must be 0

In Delta(G) = deltaH - (T x deltaS)

Delta H units are

Delta S units are

Delta H units are = jk

Delta S units are = j/mol/k (must divide by 1000)

Q is used as a reaction quotient meaning?

Measures the rate at any point in the reaction

K is the equilibrium constant meaning?

Measures rate at equilibrium

At equilibrium Delta G is always?

0

What mixture has a higher entropy?

Mixtures of reactants and products or pure samples of reactants or products?

The total entropy reaches its highest when total entropy reachers a maximum when you have equal amounts of reactant and product.

If Delta G is negative it means that…

Equilibrium favours products and K is greater than 1

If Delta G is positive it means that…

Equilibrium favours reactants and K is less than 1

If Delta G is 0 it means that…

Equilibrium contains appreciable amounts of both substances and K = 1