What To Memorize: Exam 2

Solute

The substance (solid) that is dissolved in the solvent.

Solvent

The liquid that dissolves the solute, present in greatest abundance.

Solution

A homogeneous mixture of two or more pure substances.

Aqueous Solution

A solution where water is the solvent.

Molarity (M) Defined

The concentration of a solution expressed as moles of solute per liter of solution.

Molarity Formula

M=\dfrac{n}{V} where volume in in liters

Dilution Formula

McVc = MdVd, where Mc and Md are molarities and Vc and Vd are volumes of concentrated ( c ) and dilute ( d ) solutions.

Strong Acids

Acids that completely dissociate in solution, e.g., HCl, HBr, HI, HClO₃, HClO₄, HNO₃, H₂SO₄.

Weak Acids

Acids that partially dissociate in solution, e.g., HF, CH₃COOH.

Strong Bases

Bases that completely dissociate in solution, including Group 1A metal hydroxides and heavy Group 2A metal hydroxides.

Oxidation State

The charge of an atom in a compound, with specific rules for different groups.

Balancing Redox Reactions

The process of dividing reactions into half reactions and balancing them for atoms and charge.

Acidic Solutions

Combine half reactions and cancel common terms.

Basic Solutions

Add OH- to balance H+, forming H2O, then combine half reactions.

Change in Internal Enthalpy (ΔE)

The difference in energy between products and reactants, E_{products}-E_{reactants}

Exchange of Energy

ΔE = q + w, where q is heat and w is work.

Endothermic Reaction

A reaction where ΔE > 0, indicating energy absorption.

Exothermic Reaction

A reaction where ΔE < 0, indicating energy release.

Enthalpy (H)

The total energy of a system, including internal energy and pressure-volume work.

Change in Enthalpy (ΔH)

ΔH = ΔE + PΔV, representing the change in enthalpy during a reaction.

Work (w)

PV or -PV, where P is pressure and V is volume.

Specific of Light

c = λv, where c is the speed of light, λ is wavelength, and v is frequency.

Speed of Light (c) constant

A constant value of 3.00 × 10⁸ m/s.

Energy in proportional to frequency

E = hv, where E is energy, h is Planck’s constant, and v is frequency.

Enthalpy of Reaction

\Delta H_{rxn}=H_{products}+H_{reactants}

Planck’s Constant (h)

A constant value of 6.626 × 10^-34 J·s.

Fahrenheit Conversion

F = (9/5)(°C + 32).

Celsius Conversion

C = (5/9)(°F - 32).

Kelvin Conversion

K = °C + 273.