Unit Conversions

Temperature Conversions

Temperature can be measured in Fahrenheit (°F), Celsius (°C), or Kelvin (K). Converting between these units is essential in chemistry calculations.

• Fahrenheit to Celsius:

• Celsius to Fahrenheit:

• Celsius to Kelvin:

Example: Convert 25°C to Fahrenheit:

Specific Heat of Water

• Specific Heat (SH) for H2O(l): or

Application: Used to calculate the energy required to heat or cool water.

Useful Conversion Factors

These factors are essential for converting between different units in chemistry problems.

Equations

Density

• Definition: Density is the mass of a substance per unit volume.

• Formula:

• Application: Used to identify substances and convert between mass and volume.

Molar Mass

• Definition: The mass of one mole of a substance, usually in grams per mole (g/mol).

• Formula:

• Application: Calculate the molar mass of compounds by summing the atomic masses of constituent atoms.

Molecular Weight

• Formula:

• Application: Used to convert between mass and moles in chemical calculations.

Constants

• Avogadro's Number ():

• Definition: The number of particles (atoms, molecules, ions) in one mole of a substance.

Key General Chemistry Concepts and Skills

Introduction to Chemistry

• What is a pure chemical? A substance with uniform and definite composition; not a mixture.

• Significant Figures: Digits in a measurement that are known with certainty plus one estimated digit. Note: For multiplication/division, use the fewest significant figures; for addition/subtraction, use the fewest decimal places.

Measurement and Units

• SI Units: Standard units used in scientific measurements (meter, kilogram, second, mole, etc.).

• Mass, Volume, Density: Key physical properties measured in chemistry.

Temperature Conversions

• Convert between Celsius, Fahrenheit, and Kelvin using the formulas above.

Scientific Method

• Steps: Observation, Hypothesis, Experimentation, Conclusion, and Law or Theory formation.

Classification of Matter

• Elements: Pure substances consisting of one type of atom.

• Compounds: Substances composed of two or more elements chemically combined.

• Mixtures: Physical combinations of two or more substances.

Physical and Chemical Changes

• Physical Change: Change in state or appearance without altering composition (e.g., melting ice).

• Chemical Change: Change that alters the chemical composition (e.g., rusting iron).

Periodic Table and Elements

• Groups and Periods: Vertical columns are groups (families); horizontal rows are periods.

• Metals, Nonmetals, Metalloids: Classification based on properties.

• Alkali Metals: Group 1 elements; Alkaline Earth Metals: Group 2 elements.

Law of Conservation of Mass

• Mass is neither created nor destroyed in a chemical reaction.

Atomic Structure

• Protons, Neutrons, Electrons: Subatomic particles in atoms.

• Isotopes: Atoms of the same element with different numbers of neutrons.

Electron Configuration

• Arrangement of electrons in atomic orbitals.

Compounds and Formulas

• Empirical Formula: Simplest whole-number ratio of elements in a compound.

• Molecular Formula: Actual number of atoms of each element in a molecule.

• Percent Composition: Percent by mass of each element in a compound.

Stoichiometry

• Calculations involving the quantities of reactants and products in chemical reactions.

• Use of molar mass, Avogadro's number, and balanced equations.

Types of Chemical Reactions

• Combination, Decomposition, Single Replacement, Double Replacement, Combustion

Solution Chemistry

• Homogeneous Mixtures: Uniform composition throughout (solutions).

• Solvent and Solute: Solvent is the major component; solute is dissolved in the solvent.

Concentration Units

• Molarity (M):

Dimensional Analysis

• Method for converting between units using conversion factors.

Skills Checklist

• Convert metric units (e.g., cm to m, g to kg).

• Use significant figures correctly in calculations.

• Write and interpret chemical formulas and equations.

• Balance chemical equations.

• Calculate molar mass and percent composition.

• Identify types of chemical reactions.

• Apply the law of conservation of mass.

• Use Avogadro's number in mole calculations.

Additional info: Some content was inferred and expanded for academic completeness and clarity, based on standard General Chemistry I curriculum and the provided exam equation sheet and syllabus topics.