chemistry final kms

What is thermochemistry?

The study of the relationships between heat, work, and other forms of energy in chemical and physical processes.

Define Enthalpy (H).

A thermodynamic property of a system that is the sum of the internal energy of the system plus the product of its pressure and volume: H=U+PVH=U+PV. It is often used to describe heat changes at constant pressure.

What is Hess's Law?

Hess's Law states that the enthalpy change for a reaction is independent of the pathway taken. If a reaction is carried out in a series of steps, ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps.

Define Bond Enthalpy.

The energy required to break one mole of a particular bond in the gaseous phase. It is always positive, indicating that bond breaking is an endothermic process.

What are Intermolecular Forces (IMFs)?

Attractive forces between molecules that determine the physical properties of substances like boiling point, melting point, and viscosity.

What are the three vaN der waals forces?

1. London Dispersion Forces (weakest)

2. Dipole-Dipole Interactions

3. Hydrogen Bonding (strongest)

Describe London Dispersion Forces.

Temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. Present in all molecules, but most significant in nonpolar molecules.

Describe Dipole-Dipole Interactions

Attractive forces between polar molecules. Occur when the partially positive end of one molecule is attracted to the partially negative end of another.

Describe Hydrogen Bonding

A particularly strong type of dipole-dipole interaction that occurs between a hydrogen atom bonded to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) and another electronegative atom.

What is Chemical Equilibrium?

The state in which the rate of the forward reaction equals the rate of the reverse reaction, resulting in no net change in the concentrations of reactants and products.

Define the Equilibrium Constant (K).

A quantitative measure of the extent of a reaction when it reaches equilibrium. For the reaction aA+bB⇌cC+dDaA+bB⇌cC+dD, K=[C]c[D]d[A]a[B]bK=[A]a[B]b[C]c[D]d​

State Le Chatelier's Principle.

If a change of condition (e.g., change in concentration, pressure, temperature) is applied to a system in equilibrium, the system will shift in a direction that relieves the stress.

What factors affect Chemical Equilibrium?

Concentration, Pressure, Volume, and Temperature

Define Arrhenius Acid and Base.

Arrhenius Acid: A substance that increases the concentration of H+H+ ions in aqueous solution. Arrhenius Base: A substance that increases the concentration of OH−OH− ions in aqueous solution.

Define Bronsted-Lowry Acid and Base.

Bronsted-Lowry Acid: A substance that donates a proton (H+H+). Bronsted-Lowry Base: A substance that accepts a proton (H+H+).

Define Lewis Acid and Base.

Lewis Acid: A substance that accepts an electron pair. Lewis Base: A substance that donates an electron pair.

What is pH?

A measure of the acidity or basicity of an aqueous solution. pH=−log[H+]pH=−log[H+]

Write the equation relating pH and pOH.

pH + pOH = 14

What is a buffer solution?

A solution that resists changes in pH when small amounts of acid or base are added. It typically consists of a weak acid and its conjugate base, or a weak base and its conjugate acid.

What are the properties of an Acid?

- Sour taste

• pH less than 7

• Reacts with bases to form salts and water

• Can conduct electricity

What are the properties of a Base?

- Bitter taste

• pH greater than 7

• Feels slippery

• Reacts with acids to form salts and water

• Can conduct electricity

What turns litmus paper blue?

base

what turns litmus paper red

acid

What are examples of strong acids

What are examples of strong bases

Is 12M concentrated or dilute

concentrated

What is the equation for molarity

M = (moles)/(Liters)

Write the electron configuration for the chlorine atom

1s2 2s2 2p6 3s2 3p5

List the types of IMFs from strongest to weakest:

Ionic, hydrogen bonds, dipole-dipole, london dispersion

Which law is pressure/volume

boyles law

which law is volume/temperature

charles law

which law is pressure/temperature

gay-lussacs law

How does delta H work?

How does delta S work?

How does delta G work?