Chemistry Chapter 1 Quiz

Law vs. Theory

• Laws describe a body of facts, while theories explain a body of facts.

States of Matter

• Solids: Atoms are in a fixed shape, vibrating.
• Liquids: Atoms take shape, more hitting.
• Gases: Atoms all over, most space.

Homogenous vs Heterogenous Mixtures

• Homogenous: Solution (e.g., steel, milk)
• Heterogenous: Mixture (e.g., blood, brass)

Separation Methods

• Filtration: Coffee filter
• Distillation: Heating flask
• Chromatography: Ink separation
• Electrolysis: Compounds into elements (e.g., H₂O)

Density

• Density (D) = mass (m) / volume (V) or V = m/D or m = D x V

Extensive vs Intensive Properties

• Extensive properties depend on the amount of substance (e.g., mass, volume, heat).
• Intensive properties do not depend on the amount of substance (e.g., melting point, boiling point, density).

Physical vs Chemical Changes

• Physical change: Alterations in a substance's physical properties (e.g., melting, boiling).
• Chemical change: Alterations that create new substances by rearranging atoms (e.g., reactions, burning).

Kinetic vs Potential Energy

• Kinetic Energy: Energy of motion (e.g., thermal, mechanical, electrical, acoustic).
• Potential Energy: Stored energy of position or status (e.g., gravitational, electrostatic, chemical, nuclear).

Law of Conservation of Energy

• Endothermic: Absorbs heat
• Exothermic: Emits heat

Qualitative vs Quantitative

• Qualitative: Physical appearance or feel.
• Quantitative: Numbers or units.

Temperature Conversions

• °C + 273.15 = K
• K - 273.15 = °C

Precision vs Accuracy

• Precision: How close measurements are to each other.
• Accuracy: How close measurements are to the true value.

Relative Error

• Relative error = (observed value - accepted value) / accepted value x 100%

Percentage Yield

• % yield = (actual yield / theoretical yield) x 100%

Significant Figures (Sig Figs)

• Rules for addition/subtraction: Least significant decimal place after the decimal point
• Rules for multiplication/division: Least significant figure present

Scientific Discoveries

• Rutherford: Atomic nucleus
• Millikan: Electron charge
• Thomson: Charge/mass ratio of electron
• Dalton: Atomic weight
• Becquerel/Curie: Radiation (radioactivity)

Atomic/Mass/lonic Numbers

• Atomic number (# of protons)
• Mass number (# of protons + neutrons)
• lonic charge: Ions
• Protons → lonic charge
• Proton + Neutrons

Isotopes

• Atoms of the same element with different numbers of neutrons
• (relative abundance) x (atomic mass) / 100.
• Sum it to find X

Periodic Table Trends

• Electronegativity increases across a period and decreases down a group, reflecting the tendency to gain electrons
• Ionic compounds: Metal + nonmetal, roman numerals.

Covalent Compounds

• Nonmetal + nonmetal (prefixes: mono, di, tri, tetra, penta, hexa, hepta, octa, and nona,deca).

Oxidation States

• Oxidation state: The charge an atom would have if all bonds were ionic.
• Free elements have an oxidation state of 0.
• Fluorine is always -1.
• Oxygen is usually -2.
• Group 1: +1, Group 2: +2, Group 3: +3.
• Hydrogen is usually +1; with nonmetals, +1; with metals, -1

Oxidation-Reduction (Redox) Reactions

• Oxidation: Loss of electrons
• Reduction: Gain of electrons
• Oxidizing agent: Substance causing oxidation
• Reducing agent: Substance causing reduction

Acid-Base Reactions

• Acids react with bases to produce water and a salt.
• H₂SO₄ + NaOH → H₂O + Na₂SO₄.

Stoichiometry

• The quantitative relationships between reactants and products in a chemical reaction (balancing).
• Limiting reactant: The reactant that is completely used up first in a reaction

Molarity

• Moles of solute / Liters of solution

Percent Composition

• % element = ((Molar mass of element) / (Molar mass of compound)) × 100

Empirical Formula

• Simplest whole-number ratio of atoms in a compound

Molecular Formula

• Actual number of atoms of each element in a molecule

Gram-Molecular Mass

• The mass in grams of one mole of a substance. (Molar Mass)

Mole Conversions

• Moles = mass / molar mass
• Moles = number of particles / Avogadro's number

Photons

• E photon = hc / λ

Electromagnetic Radiation

• The energy-carrying waves; radio-infrared-microwaves-visible-ultraviolet-x-rays-gamma
• Wavelength-Frequency

Bohr Theory

• Electron orbits around the nucleus.

Electron Configurations

• Arrangement of electrons in orbitals and sublevels
• Quantum numbers (n, l, ml, and ms).

Hybridisation

• The concept of hybridization describes the mixing of atomic orbitals in an atom to form hybrid orbitals that participate in chemical bonding.

Test your knowledge on the fundamental concepts of chemistry with this quiz. Topics include the characteristics of gases, heterogeneous mixtures, density formulas, types of changes, significant figures, and standard deviation calculations. Perfect for students looking to reinforce their understanding of basic chemical principles.