Fall All Semester Review

First Law of Thermodynamics

The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted from one form to another.

Second Law of Thermodynamics

The second law of thermodynamics states that the entropy of an isolated system always increases over time.

Entropy

Entropy is a measure of the disorder or randomness of a system.

Third Law of Thermodynamics

The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero is zero.

Heat Transfer

Heat is transferred through conduction, convection, and radiation.

Closed System

A closed system is one where matter cannot enter or leave, but energy can be exchanged.

Open System

An open system is one where both matter and energy can be exchanged with the surroundings.

Endothermic Reactions

Endothermic reactions absorb heat.

Exothermic Reactions

Exothermic reactions release heat.

Synthesis Reaction

A synthesis reaction is a type of chemical reaction where two or more reactants combine to form a single product (A + B → AB).

Decomposition Reaction

A decomposition reaction is a type of chemical reaction where a compound breaks down into two or more simpler substances (AB → A + B).

Single Replacement Reaction

A single replacement reaction occurs when one element replaces another element in a compound (A + BC → AC + B).

Double Replacement Reaction

A double replacement reaction occurs when two compounds react, and the cations and anions switch places (AB + CD → AD + CB).

Combustion Reaction

A combustion reaction is a reaction where a substance combines with oxygen, releasing energy in the form of heat and light (e.g., CH₄ + 2O₂ → CO₂ + 2H₂O).

General Form of Synthesis Reaction

A + B → AB.

General Form of Decomposition Reaction

AB → A + B.

Single Replacement Reaction Reactivity

In a single replacement reaction, if the metal is more reactive than the one it replaces, the metal will replace the less reactive metal in the compound.

Recognizing Combustion Reaction

A combustion reaction will have oxygen (O₂) as one of the reactants and produce carbon dioxide (CO₂) and water (H₂O) as products.

Products of Combustion Reaction

The products are always carbon dioxide (CO₂) and water (H₂O).

Predicting Products of Synthesis Reaction

Combine the reactants to form a single product.

Predicting Products of Decomposition Reaction

Break the compound into its component elements or simpler compounds.

First Step in Balancing Chemical Equation

Write the unbalanced equation with the correct formulas for all reactants and products.

Law of conservation of mass

To ensure the law of conservation of mass is followed, where atoms are neither created nor destroyed.

Balancing equations

Balance atoms of elements that appear in only one reactant and one product.

Coefficient in a balanced chemical equation

The coefficient is a number placed in front of compounds or elements to balance the number of atoms on each side of the equation.

Balancing oxygen in combustion reactions

Oxygen is typically balanced last by adjusting the coefficient in front of O₂.

Predicting products in double replacement reactions

Swap the cations of the two reactants and form the new compounds.

Common method for balancing combustion reactions

Balance carbon atoms first, then hydrogen, and finally oxygen.

Balancing reactions with polyatomic ions

Treat polyatomic ions as a single unit when balancing if they appear unchanged on both sides.

Subatomic particles in an atom

Protons, neutrons, and electrons.

Location of protons in an atom

Protons are found in the nucleus of an atom.

Isotope

An isotope is an atom of the same element that has a different number of neutrons.

Differences between isotopes of the same element

They have the same number of protons but a different number of neutrons.

Atomic number of an element

The atomic number is the number of protons in the nucleus of an atom.

Mass number of an atom

The mass number is the sum of protons and neutrons in an atom's nucleus.

Calculating number of neutrons in an atom

Subtract the atomic number from the mass number (Neutrons = Mass Number - Atomic Number).

Charge of a proton

The charge of a proton is +1.

Charge of an electron

The charge of an electron is -1.

Charge of a neutron

A neutron has no charge (it is neutral).

Naming a simple ionic compound

Name the cation (metal) first, followed by the anion (non-metal) with an '-ide' suffix.

Naming a binary covalent compound

Use prefixes (mono-, di-, tri-, etc.) to indicate the number of atoms, followed by the name of the first element and the second element with an '-ide' suffix.

Naming an acid with no oxygen

Use the prefix 'hydro-' and the suffix '-ic acid.'

Naming an acid with oxygen

If the anion ends in '-ate,' the acid name ends in '-ic acid'; if the anion ends in '-ite,' the acid name ends in '-ous acid.'

Name of NaCl

Sodium chloride.

Name of H₂SO₄

Sulfuric acid.

Name of HNO₃

Nitric acid.

Name of CO₂

Carbon dioxide.

Name of H₂CO₃

Carbonic acid.

Calculating average atomic mass

Multiply the mass of each isotope by its relative abundance and add the results.

Units for atomic mass

Atomic mass is measured in atomic mass units (amu).

Average atomic mass calculation example

(10 amu × 0.75) + (12 amu × 0.25) = 10.5 amu.

Average atomic mass of chlorine

(35 × 0.75) + (37 × 0.25) = 35.5 amu.

Different isotopes

Different isotopes have different numbers of neutrons, leading to different masses.

Electron configuration

Electron configuration describes the arrangement of electrons in an atom.

Electron configuration for oxygen

1s² 2s² 2p⁴.

Filling orbitals in electron configuration

Follow the Aufbau principle, filling orbitals from lowest to highest energy, and obey the Pauli exclusion principle and Hund's rule.

The 's' in 1s²

The 's' refers to the type of orbital, which can hold up to two electrons.

Electron configuration of sodium (Na)

1s² 2s² 2p⁶ 3s¹.

Maximum number of electrons in second energy level

8 electrons.

Electron configuration for carbon

1s² 2s² 2p².

Aufbau principle

Electrons fill orbitals starting from the lowest energy level.

Electron configuration of chlorine ion

1s² 2s² 2p⁶ 3s² 3p⁶.

First atomic theory

John Dalton.

J.J. Thomson's discovery

J.J. Thomson discovered the electron using the cathode ray tube.

Niels Bohr's model of the atom

Niels Bohr proposed that electrons orbit the nucleus in fixed paths or energy levels.

Ernest Rutherford's experiment

Rutherford conducted the gold foil experiment and discovered the nucleus of the atom.

Discovery of the neutron

The neutron explained the additional mass in atoms that was not accounted for by protons alone.

Relationship between energy, frequency, and wavelength

The energy of a photon is directly proportional to its frequency and inversely proportional to its wavelength (E = hν, where h is Planck's constant, and ν is frequency).

Planck's constant

Planck's constant is 6.626 × 10⁻³⁴ J·s.

Calculating wavelength from frequency

Use the equation λ = c/ν, where λ is the wavelength, c is the speed of light, and ν is the frequency.

Speed of light in a vacuum

The speed of light is approximately 3.00 × 10⁸ m/s.

Frequency of light with wavelength of 500 nm

Use the equation ν = c/λ. For λ = 500 nm (5 × 10⁻⁷ m), ν = (3 × 10⁸ m/s) / (5 × 10⁻⁷ m) = 6 × 10¹⁴ Hz.

Energy of a photon with frequency of 4 × 10¹⁴ Hz

E = hν = (6.626 × 10⁻³⁴ J·s) × (4 × 10¹⁴ Hz) = 2.65 × 10⁻²⁰ J.

Energy of light as wavelength increases

As the wavelength increases, the energy of light decreases.

Formula to calculate energy of a photon

E = hν.

Energy change when frequency is doubled

The energy doubles, because energy is directly proportional to frequency.

Wavelength of light with energy of 4 × 10⁻¹⁹ J

Use the formula E = hc/λ.

Energy-Wavelength Formula

E = hc/λ

Wavelength Rearrangement

λ = hc/E

Wavelength Calculation Example

λ = (6.626 × 10⁻³⁴ J·s)(3.00 × 10⁸ m/s) / (4 × 10⁻¹⁹ J) = 4.97 × 10⁻⁷ m or 497 nm.

Wavelength and Frequency Relationship

Wavelength and frequency are inversely related; as the wavelength increases, the frequency decreases, and vice versa.

Wavelength from Frequency

λ = c/ν, λ = 3 × 10⁸ m/s / (2 × 10¹⁴ Hz) = 1.5 × 10⁻⁶ m or 1500 nm.

Unit of Frequency

The unit of frequency is the hertz (Hz), which is equivalent to one cycle per second.

Energy and Wavelength Relationship

The energy of light increases as the wavelength decreases.

Proton Discovery

Ernest Rutherford discovered the proton through his gold foil experiment, where he observed the deflection of alpha particles.

Bohr's Atomic Model

Niels Bohr proposed the planetary model of the atom, where electrons orbit the nucleus in specific energy levels, explaining the stability of electrons in an atom.

Mendeleev's Contribution

Dmitri Mendeleev created the periodic table, arranging elements by increasing atomic mass and predicting the properties of elements that had not yet been discovered.

Electron Configuration for Neon

The electron configuration for neon (atomic number 10) is 1s² 2s² 2p⁶.

P Orbital Capacity

The p orbital can hold up to 6 electrons.

Electron Configuration for Mg²⁺

The electron configuration for Mg²⁺ (atomic number 12) is 1s² 2s² 2p⁶.

Maximum Electrons in Third Energy Level

The third energy level can hold a maximum of 18 electrons.

Electron Configuration for Aluminum

The electron configuration for aluminum (atomic number 13) is 1s² 2s² 2p⁶ 3s² 3p¹.

Weighted Average Atomic Mass Calculation

Multiply the mass of each isotope by its fractional abundance and add them together.

Atomic Mass of Carbon

The atomic mass of carbon is an average of the masses of its isotopes, based on their natural abundances.

Name of Na₂SO₄

Sodium sulfate.

Name of FeCl₃

Iron(III) chloride.

Name of H₃PO₄

Phosphoric acid.

Naming Ionic Compounds with Transition Metals

The charge of the transition metal is indicated using Roman numerals in parentheses.

Name of CuSO₄

Copper(II) sulfate.

Isotope Notation for Carbon-14

The isotope notation for carbon-14 is ¹⁴C.