Chapter1

Chapter One: Matter, Energy, and Measurements

Overview

  • Course: CH 103 – Introduction to Inorganic and Organic Chemistry

  • Institution: Passaic County Community College

  • Author: Dr. Fred Safarowic, Professor of Chemistry

  • Graphics: Cengage Publishing

Chemistry: The Study of Matter

  • Definition of Matter:

    • Anything that has mass and takes up space.

    • Exists in three phases: solid, liquid, or gas.

    • Matter can undergo changes.

Changes in Matter

Chemical Changes

  • Definition: Transformation of one substance into another via chemical reactions.

  • Example:

    • Sodium (Na) reacts with Chlorine (Cl) to form sodium chloride (NaCl).

Physical Changes

  • Definition: Changes in the state of matter without altering the identity of the substance.

  • Example:

    • Water transitioning from solid (H2O(s)) to liquid (H2O(l)) to gas (H2O(g)).

The Scientific Method

  • Steps in Scientific Inquiry:

    1. Observation: Gather factual information.

    2. Hypothesis: Develop a statement that provides a potential explanation (needs testing).

    3. Theory: A hypothesis supported by evidence becomes a theory.

Measurements in Chemistry

Common Measurements

  • Length: 1 in. = 2.54 cm

  • Mass: 1 oz = 28.35 g

  • Volume: 1 qt = 0.946 L

  • Conversions:

    • 1 m = 39.37 in.

    • 1 lb = 453.6 g

    • 1 gal = 3.785 L

    • 1 mile = 1.609 km

    • 1 kg = 2.205 lb

    • 1 L = 33.81 fl oz

    • 1 g = 15.43 grains

    • 1 fl oz = 29.57 mL

    • 1 L = 1.057 qt

Metric System and SI Units

  • The metric system is widely used except in the US.

  • Scientists commonly use the SI (International System of Units).

  • Conversions can be done by changing the prefix based on powers of ten.

Length Measurement

Metric Prefixes

  • Base Unit: Meter (m)

  • Common Prefixes:

    • Giga (G): 10^9 = 1,000,000,000

    • Mega (M): 10^6 = 1,000,000

    • Kilo (k): 10^3 = 1,000

    • Deci (d): 10^-1 = 0.1

    • Centi (C): 10^-2 = 0.01

    • Milli (m): 10^-3 = 0.001

    • Micro (µ): 10^-6

    • Nano (n): 10^-9

    • Pico (p): 10^-12

Volume Measurement

  • Base Unit: Liter (L)

  • Relation to Milliliters:

    • 1,000 mL = 1 L

    • 1 cc = 1 mL

Mass Measurement

  • Definition: Quantity of matter in an object.

  • Base Unit: Gram (g)

  • Relationship:

    • 1 kg = 1,000 g

    • 1 g = 1,000 mg

  • Note: Mass is not the same as weight.

Temperature Measurement

  • Temperature Scale: Kelvin

  • Celsius Scale:

    • Water boils at 100°C

    • Water freezes at 0°C

  • Conversion: K = 273 + °C

  • Absolute Zero: Lowest temperature possible is -273°C = 0 K.

Factor-Label (Dimensional Analysis)

  • Method:

    • Multiply numbers and units when converting.

    • Divide to cancel units properly.

  • Example: Conversion of grams to pounds:

    • To convert 381 g to lb using the conversion factor (1 lb = 453.6 g), it needs to be set up properly for correct cancellation.

Conversion Examples

  1. Distance Example:

    • Distance between Rome and Milan: 535 km to miles.

  2. Volume Example:

    • Olive oil container: 1.844 gal to mL.

  3. Medical Example:

    • Adding 100 mg of morphine to 500 cc of IV fluid at 20 cc/h; convert to grams per second (g/s).

Density

  • Definition: Mass per unit volume.

  • Formula: D = m/v where D = density, m = mass, v = volume.

  • Temperature Dependency: Density usually decreases with increasing temperature.

  • Units:

    • Gases: g/L

    • Liquids/Solids: g/mL.

Specific Gravity

  • Definition: Ratio of the density of a substance to the density of a reference (usually water).

  • Note: Density of water = 1 g/mL.

  • Calculation: Specific Gravity = Density of Substance / Density of Reference

Energy

  • Definition: Ability to do work.

  • Types of Energy:

    • Kinetic Energy: Energy of motion.

    • Potential Energy: Stored or chemical energy.

  • Law of Conservation of Energy: Energy cannot be created or destroyed, only transformed from one form to another.