chem 108, chapter 1

Chapter 1: Measurement and the Properties of Matter

• Author: Martin McCarthy

• Source: McGraw Hill LLC

Importance of Chemistry

• Learning changes everything.

• Chemistry is integral to various fields:

  • Health and Medicine

    • Sanitation systems

    • Surgery with anesthesia

    • Vaccines and antibiotics

    • Gene therapy

  • Energy and the Environment

    • Fossil fuels

    • Solar energy

    • Nuclear energy

  • Materials and Technology

    • Polymers, ceramics, liquid crystals

    • Room-temperature superconductors

    • Molecular computing

  • Food and Agriculture

    • Genetically modified crops

    • “Natural” pesticides

    • Specialized fertilizers

The Study of Chemistry

• Utilizes systematic approaches for research through the scientific method.

The Scientific Method

1. Hypothesis: A tentative explanation for observations.

2. Law: A concise statement of consistent relationships in experiments.

3. Theory: A unifying principle that explains a body of facts or laws.

International System of Units (SI)

• Base quantities and their respective units:

  • Length: meter (m)

  • Mass: kilogram (kg)

  • Time: second (s)

  • Electrical current: ampere (A)

  • Temperature: kelvin (K)

  • Amount of substance: mole (mol)

  • Luminous intensity: candela (cd)

SI Unit Prefixes

• Common prefixes for SI units:

  • exa- (E): 10^18

  • peta- (P): 10^15

  • tera- (T): 10^12

  • giga- (G): 10^9

  • mega- (M): 10^6

  • kilo- (k): 10^3

  • deci- (d): 10^-1

  • centi- (c): 10^-2

  • milli- (m): 10^-3

  • micro- (µ): 10^-6

  • nano- (n): 10^-9

  • pico- (p): 10^-12

  • femto- (f): 10^-15

  • atto- (a): 10^-18

Volume and Density

• Volume: SI derived unit is cubic meter (m³).

  • Conversion:

    • 1 cm³ = 1 mL

    • 1 L = 1000 mL

• Density:

  • Formula: Density (d) = mass (m) / volume (V)

  • SI unit is kg/m³

  • 1 g/cm³ = 1000 kg/m³

• Densities of some substances (at 25°C):

  • Hydrogen: 0.0000899 g/cm³

  • Water: 1.00 g/cm³

  • Gold: 19.3 g/cm³

Temperature Scales

• Conversion formulas:

  • Kelvin to Celsius: K = °C + 273.15

  • Celsius to Fahrenheit: °F = (°C × 9/5) + 32

Significant Figures

• Numbers are significant based on certain rules:

  • Non-zero digits are significant.

  • Zeros between non-zero digits are significant.

  • Leading zeros are not significant.

  • Trailing zeros in a decimal are significant.

Dimensional Analysis

• A method for unit conversion:

  • Identify conversion factors needed.

  • Carry units throughout the calculation.

  • Ensure all unwanted units cancel out.

Examples and Problem Solving

• Calculations involving density, conversions between units (lbs to grams, liters to milliliters).

• Practical applications of chemical principles to everyday situations, demonstrating the relevance of chemistry in life.