Chemistry SOL Study Guide

Percent Error
(measured-standard)/standard X 100 = (known-found)/known X 100

Ideal Gas Law
PV = nRT (or if the question has V & moles: 22.4 liters/mole at STP)

Boyle’s Law
P₁V₁= P₂V₂
“kinetic molecular theory of gases”

Charles’ Law
V₁/T₁ = V₂/T₂ (in Kelvin)

Kelvin Temperature
°C + 273

Molarity
moles/liters

Density
Mass/Volume

Partial Pressures
Add up to Dalton’s law
Ptotal = P₁ + P₂ + P₃+ etc.

Heat Energy (enthalpy)
H = (Mass)(ΔT)(c)

Heat of Fusion (Vaporization)
(Mass)(Heat of Fusion)

Accuracy
How close a measurement is to the correct answer (the standard)

Precision
How closely measurements agree with each other

Ammonium
NH4⁺¹

Hydroxide
OH⁻¹

Nitrate
NO3⁻¹

Carbonate
CO3⁻²

Sulfate
SO4⁻²

Phosphate
PO4⁻³

Group Names
Alkali Metals (+1) Alkaline Earth Metals (+2) Halogens (-1) Noble Gases

Diatomic Gases
B₂R₂I₂N₂Cl₂H₂O₂F₂

Isotopes
Atoms with the same atomic number (protons) but different masses (neutrons)

Half Life
Example: If the half life is 12 years, how many out of 512 original grams remain after 48 years?
48/12 = 4 half lives. 512 → 256 → 128 → 64 → 32

Synthesis (Direct Combination)
A + B = C

Decomposition
A = B + C

Single Displacement
Element + Compound + Other Element + Compound

Combustion of Hydrocarbon
C₅H₁₂ + 8O₂ = 5CO₂ + 5H₂O

Neutralization
HCl + NaOH = NaCl + H₂O

Significant Figures (Addition/Subtraction)
When adding or subtracting sig figs. look at decimal position: 3.123 + 24.5 = 27.6

Significant Figures (Multiplication/Division)
When multiplying or dividing, use the least number of sig figs: 23.045 X 2.1 – 48.3945 = 48

SI Units
Kilo hecto deka unit deci centi milli micro nano pico

Writing Formulas
When writing formulas, criss cross the oxidation numbers: calcium Ca⁺² chloride Cl⁻¹ becomes CaCl₂

Acid Ions and pH
hydrogen H⁺ and pH below 7
pH + pOH = 14

Base Ions and pH
hydroxide OH⁻ and pH above 7

Equilibrium Expression
For aA(s) + bB(g) ⇌cC(aq) + dD(g)
K = (C)^c (D)^d/(A)^a(B)^b

Combined Gas Law
P1V1/T2 = P2V2/T2