General Chemistry I Practice Exam 2 Flashcards

A set of vocabulary flashcards based on General Chemistry I lecture notes and exam problems covering thermodynamics, quantum mechanics, periodic trends, and molecular geometry.

System

The specific thing or part of the universe being studied.

Surroundings

Everything in the universe that is not part of the system.

$$\Delta E$$

The change in internal energy, calculated as the sum of heat ($q$) and work ($w$).

Exothermic

A reaction in which heat is released ($\Delta H <0$).

Single Displacement Reaction

A chemical reaction where one element is replaced or 'kicked out' by another in a compound.

Standard Enthalpy of Formation ($\Delta H_f^0$)

The heat change when exactly $1\,mole$ of a compound is formed from its elements in their standard forms.

Principal Quantum Number ($n$)

Represents the energy level; low $n$ correlates to low energy and being closer to the nucleus, while high $n$ correlates to high energy.

s-orbital

An orbital with a spherical shape and an angular momentum quantum number of $l = 0$.

p-orbital

An orbital shaped like a peanut.

d-orbital

An orbital shaped like a 4-leaf clover.

Spin Quantum Number ($m_s$)

A quantum number that indicates the direction of electron spin, with possible values of $+1/2$ or $-1/2$.

Valence Electrons

Electrons in the outermost energy level of an atom.

Diamagnetic

A condition where all electrons in a species are paired.

Paramagnetic

A condition where at least one electron in a species is not paired.

Acidic Oxide

Oxides formed typically by non-metals; example given in notes is $N_2O_5$.

Electronegativity

The ability of an atom to attract electrons, with Fluorine ($F$), Oxygen ($O$), and Nitrogen ($N$) being the most electronegative.

Lattice Energy

The energy of attraction in an ionic compound; it is greater when ions are smaller and more closely attracted to each other.

Volatility

A characteristic of a substance that turns into a gas or evaporates easily.

Formal Charge ($FC$)

The charge assigned to an atom in a Lewis structure, calculated as $VE - \text{unshared } VE - 0.5 \times \text{shrd } VE$.

Electron-Group Arrangement

The spatial arrangement of all electron groups (bonding and lone pairs) surrounding a central atom.

Molecular Geometry

The 3D arrangement of only the bonding atoms in a molecule.

Bond Length

The distance between bonded atoms; shorter bonds generally occur between smaller atoms.

Tungsten ($W$)

The metal noted for having the highest melting point.