AP Chemistry Midterm Flashcard

for AP Chemistry midterms

Ionic Bond

Between nonmetals and metals; transfer of electrons

Covalent Bond

Between nonmetals only; share of electrons

Metallic Bond

Between metals only; sea of electrons

Mass Spectroscopy

a technique used to identify the isotopes of an element and their relative abundance in nature

Empirical Formula

the lowest whole number ratio of atoms of each element in a compound

Photoelectron Spectroscopy

an experiment that determines the relative energy of electrons in atoms

Electronegativity

an atom’s ability to attract electrons to itself

What does a potential energy curve depict?

a bond being made or being broken based on perspective; the peak of the graph shows when/where the bond is formed; the x-axis is the bond length; the y-axis is the bond energy

Cation

“+” ion; cations are PAWsitive

Anions

“-” ions; Anions are ANtagonistic

Delocalized Electrons

electrons that roam freely in a metallic bond

Alloy

a combination of two or more metals

Substitutional Alloy

Alloy made of two similar sized metals

Interstitial Alloy

Alloy made of metals where one metal element is distinctly larger than the other

Formal Charge

(# of valence electrons) - (# of valence electrons in molecule)

Linear VSEPR shape

180 degrees with 3 atoms

Bent VESPR shape

120 degrees with 3 atoms

Trigonal Planar VESPR shape

120 degrees with 4 atoms

Pyramidal VESPR shape

109 degrees with 4 atoms

Tetrahedral VESPR shape

109 degrees with 5 atoms

Intermolecular Force (IMF)

A force that exists between molecules

Ion-Dipole

Ionic-polar bond; Strongest IMF

Hydrogen Bonding

Only polar bond; Second Strongest IMF

Dipole-Dipole

Only polar bond; Third Strongest IMF

Dipole-Induced

Polar + Nonpolar bond; Second Weakest IMF

London Dispersion Forces

Nonpolar only bond; Weakest IMF

Ideal Gas Law Equation

PV=nRT

Dalton’s Partial Pressure Theory

P_total = P_a+P_b+P_c…

What does the Maxwell-Boltzmann Distribution Curve represent?

It depicts the amount of particles vs the speed of a gaseous substance

What is the difference between a real gas and an ideal gas?

Real gases do not follow ideal gas laws: ideal gases = elastic collisions, high temps, low pressure, and no molecular interactions

Molarity Equation

M = mol/L

Chromatography

A process that separates components due to their IMFs.

Distillation

A process that separates components due to their boiling point.

What does “like dissolves like” mean?

Polar dissolves polar… Nonpolar dissolves nonpolar

Examples of a Physical Reaction

boiling, grinding, cutting

Examples of a Chemical Reaction

burning, rusting, igniting

Spectator Ion

Substances that are not active involved in a reaction

In a redox reaction, what happens to the substance that is reduced?

It gains electrons (GER)

In a redox reaction, what happens to the substance that is oxidized?

It loses electrons (LEO)

When studying reaction rates, do we study the rate of appearance of products, or the rate of disappearance of reactants?

Rate of disappearance of reactants

What are three scenarios that will increase the rate of a reaction?

temperature, surface area, and reactant concentration

If the initial rate does not change when the concentration does, then the reaction order is…

zero order.

If the initial rate has the same change as the concentration change, then reaction order is…

first order.

If the initial rate becomes the square of the concentration changes, then the reaction order is…

second order.

Zero Order Reactions Graph

[x] vs time

First Order Reactions Graph

ln[x] vs time

Second Order Reactions Graph

1/[x] vs time

What order are half life reactions?

First-order

Elementary Reaction

a process that occurs in a single step

When writing a reaction rate from elementary reactions, is the rate determined from the slow step or the fast step?

The slow step

What is the difference between an intermediate and a catalyst?

an intermediate is formed and consumed during the reaction while a catalyst is present as a reactant and product in the reaction.

Is energy absorbed or released when a bond breaks?

absorbed

Is energy absorbed or released when a bond is formed?

released

Endothermic Reactions

Absorbs energy… change in enthalpy is positive

Exothermic Reactions

Releases energy… change in enthalpy is negative

On a heating curve, during a phase change, what 2 variables do not change?

Temperature and Kinetic Energy

Bond Enthalpy Equation

Bond Enthalpy of Reactants - Bond Enthalpy of Products = Bond Enthalpy

Enthalpy of Formation Equation

Change in Enthalpy = Sum of Change in Enthalpy of Products - Sum of Change in Enthalpy of Reactants