CHEM 107 - EXAM 2

TAMUG

Number of Electron Groups: 2

Lone Pairs: 0

Ideal Bond Angle: ?

Linear, 180

Number of Electron Groups: 3

Lone Pairs: 0

Ideal Bond Angle: ?

Trigonal Planar, 120

Number of Electron Groups: 3

Lone Pairs: 1

Ideal Bond Angle: ?

Bent, 120

Number of Electrons Groups: 4

Lone Pairs: 0

Ideal Bond Angle: ?

Tetrahedral, 109.5

Number of Electrons Groups: 4

Lone Pairs: 1

Ideal Bond Angle: ?

Trigonal Pyramidal, 109.5

Number of Electrons Groups: 4

Lone Pairs: 2

Ideal Bond Angle: ?

Bent, 109.5

Number of Electron Groups: 5

Lone Pairs: 0

Ideal Bond Angle: ?

Trigonal Bipyramidal, 90 and 120

Number of Electron Groups: 5

Lone Pairs: 1

Ideal Bond Angle: ?

See-saw, 90 and 120

Number of Electron Groups: 5

Lone Pairs: 2

Ideal Bond Angle: ?

T-shaped, 90

Number of Electron Groups: 5

Lone Pairs: 3

Ideal Bond Angle: ?

Linear, 180

Number of Electron Groups: 6

Lone Pairs: 0

Ideal Bond Angle: ?

Octahedral, 90

Number of Electron Groups: 6

Lone Pairs: 1

Ideal Bond Angle: ?

Square Pyramidal, 90

Number of Electron Groups: 6

Lone Pairs: 2

Ideal Bond Angle: ?

Square Planar, 90

What measurement for gasses is used?

Volume

What is the resultant from molecular collisions between gas molecules and container walls?

Pressure

What is the weight of air per unit of area?

Atmospheric pressure

What measures the atmospheric pressure?

Barometer

One atm

760 mmHg

1 mmHg

1 torr

Which law states that both pressure and volume are inversely proportional?

Boyle’s Law

Which law states that both pressure and temperature are directly proportional?

Gay Lussac’s Law

Which law states that both volume and temperature are directly proportional?

Charles’ Law

P₁V₁ / T₁ = P₂V₂ / T₂

Combined Gas Law

Which law states that volume and moles are directly proportional?

Avogadro’s Law

PV = nRT

Ideal Gas Law

What is the constant-R equal to?

0.0821 L atm mol-1 K-1

At STP, what does one mole of gas contain?

22.4 L

An atom with its electrons in their lowest energy locations are in what?

Ground State

When an atom is promoted to a higher energy, an atom is in a what?

Excited State

What is the arrangement of electrons in the space around the nucleus of the atom?

Electron Configuration

What are three levels for electron configuration?

Shells, subshells, orbitals

Each orbital has two electrons which in a property known as what?

Spin

Two electrons occupying the same orbital must have opposite spins is defined in what?

Pauli’s Exclusion Principle

What is the range of visible light?

400-800 nm

What is the outermost electron shell of an atom?

Valence Shell

Which electrons are the most loosely bound and responsible for chemical reactivity of elements?

Valence Electrons

List all exceptions and their noble gas electron configuration

Chromium [Ar] 4s1 3d5

Copper [Ar] 4s1 3d10

Molybdenum [Kr] 5s1 4d5

Silver [Kr] 5s1 4d10

Which periodic property increases from up to down in a group and decreases left to right in a period?

Atomic Size

What is the energy required to remove an outermost electron from a gaseous atom, forming a cation?

Ionization Energy

If an electron is more strongly held to an atom, what happens to Ionization Energy (Increases/Decreases)?

Increases

If atomic size increases, what happens to Ionization Energy (Increases/Decreases)?

Decreases

What is the amount of energy released when an electron is added to a neutral atom?

Electron Affinity

If electron affinity is greater (more negative), what happens to the stability of the anion (Increases stability/Decreases stability)?

Increases stability

Why does H and He not follow the Octet Rule?

Stable at two valence electrons

Which element is an exception to the Octet Rules and has less than 8 valence electrons?

Boron

Which elements are an exception to the Octet Rule and have more than 8 valence electrons?

Phosphorus, Sulfur

Which elements are an exception to the Octet Rule and located in the d-block?

Transition Elements

Which bond is the electrostatic attraction of ions?

Ionic Bond

Which bond shares electrons?

Covalent Bond

What are metal atoms bonded to several other atoms?

Metallic Bond

What is the formation of ionic bonds, in terms of energy?

Exothermic

What is the equal or near-equal sharing of electrons within a bond?

Nonpolar Covalent Bond

What is the unequal sharing of electrons within a bond?

Polar Covalent Bond

Which periodic trend increases from left to right and decreases top to bottom?

Electronegativity

What happens to a bond if electronegativity increases?

Polarity Increases

Electronegativity difference of 0 - 0.4 is classified as…?

Nonpolar Covalent

Electronegativity difference of 0.4 - 2 is classified as…?

Polar Covalent

Electronegativity difference of 2 and higher is classified as…?

Ionic

“Like dissolves like” means what?

Polar dissolves Polar, Nonpolar dissolves nonpolar

Which melting and boiling points are higher, Polar or Nonpolar?

Polar

What is the resultant of compound with a nonmetal and metal?

Ionic

What is the resultant of compound with nonmetals only?

Covalent

The strength of the covalent bond is equivalent to what?

Pairs

What does VSEPR (Valence-shell electron-pair repulsion) do?

Predicts the shapes of molecules and polyatomic ions

What happens to electrons in the electron-sea model?

Delocalized throughout the whole crystal structure

Metallic bond strength increase with what properties?

Decreasing atomic size and Increasing number of valence electrons

How are carbon atoms in diamond joined?

Covalent bonds in a tetrahedral geormetry

How are carbon atoms in graphite bonded?

Sheets

What is the electron-sea model?

A “sea” of positive ions and electrons encompassing ions

How does the electron-sea model contribute towards metals?

Makes electricity possible

When a force is applied to a model, what happens to the electrons?

The flow of electrons maintains the bonding

The band populated by valence electrons is the what?

Valence band

The empty band above the valence band is the what?

Conduction band

The energy difference between the bands is the what?

Band Gap

How does current work?

Electrons move from the valence band to the conductor band

What is doping?

Adding trace amounts of an element to a substance to modify its properties

What can doping modify?

Semiconductors

How is N-type prepared?

Doping with a valence electron rich element

What is the resultant of N-type doping?

Increases electrical properties

What is the resultant of P-type doping?

Decreases electrical properties

How is P-type prepared?

Doping with a valence electron deficient element

What are P-type and N-type required for?

Transistors

What are Intramolecular Forces?

The bonds within molecules

What are Intermolecular Forces?

The bonds between molecules

What is strongest Intermolecular Force?

Hydrogen Bonding

Which elements can cause Hydrogen Bonding to occur?

Fluorine (F), Oxygen (O), Nitrogen (N)

Why does the density of water decreases when it is a solid?

Molecules expand outward due to Hydrogen Bonding

What requires energy to break for water molecules, in order to achieve a state of matter?

Intermolecular Forces

What molecules have dipole-dipole attractions?

Polar molecules

What does London Dispersion Forces depend on?

Molecular size

If the LDFs increases, then the molecular size (increases/decrease)

Increases

Energy is the ability to do what?

Work and transfer heat

Energy used to cause an object that has a mass to move is called what?

Work

Energy used to cause the temperature of an object to rise is called what?

Heat

What is the SI unit of energy?

Joules

What is the non-SI unit of energy that is commonly used?

Calorie

What is defined as the energy required to raise the temperature of 1 gram of water by one Celsius?

1 Calorie

1 cal is equivalent to what?

4.184 Joules

1000 cal is equivalent to what?

1 food Cal

Thermochemistry is the study of what?

Energy transformations involved within a chemical reaction