Inorganic Chemistry Unit 1 Vocabulary

Fundamentals of Chemistry and Scientific Method

• Inorganic Chemistry Focus:

  • Inorganic chemistry is the branch of chemistry concerned with the properties, behavior, and synthesis of inorganic compounds.

• Core Chemistry Vocabulary:

  • Chemistry: The study of matter, its interactions, and the changes it undergoes.

  • Matter: Anything that takes up mass or occupies space.

  • Pure Chemistry: The pursuit of chemical knowledge for its own sake, driven by curiosity to acquire new knowledge without a specific direct application.

  • Applied Chemistry: Scientific research directed toward a specific practical goal or problem to solve.

  • Theory: An explanation of why a phenomenon happens, based on comprehensive evidence and testing.

  • Law: A summary statement of WHAT happens under specified conditions, often expressed mathematically.

• Observation and Data Types:

  • Observation: The process of obtaining data by looking at and describing physical properties.

  • Qualitative Data: Descriptive data received from observations (e.g., colors, texture, appearance).

  • Quantitative Data: Numerical data obtained directly from measurements.

• Visual Clarity Classifications (Qualitative Observations):

  • Clear / Transparent: Material that can be completely seen through.

  • Cloudy / Translucent: Material where parts are seen through accompanied by solid clouding.

  • Opaque: Material that cannot be seen through at all (e.g., milk).

Measurement Systems, Units, and Physical Quantities

• Critical Axiom:

  • UNITS MATTER: Every measurement must always include an appropriate unit to convey meaningful scientific information.

• International System of Measurement (SI):

  • The scientific system of measurement based on the metric system.

  • Common SI Units:

  • Kilogram ($kg$) for mass

  • Liter ($L$) for volume

  • Meter ($m$) for length

• Volume Equivalences and Derived Units:

  • Volume Equivalences:

  • 1\n,cm^3 = 1\n,mL

  • 1\n,dm^3 = 1\n,L

  • Density:

  • Density is a derived unit made up of combinations of other fundamental units.

• Temperature Scale and Key Benchmarks:

  • Absolute Zero:

  • Value: -273\n,^\ncirc\text{C}

  • Kelvin Scale:

  • Conversion Formula: $K = ^\circ\text{C} + 273$

  • Scale Constraint: Negative values are impossible on the Kelvin scale (0\n,K is the lowest possible temperature).

  • Benchmark Temperatures:

  • 0\n,^\circ\text{C}: Freezing point and melting point of water; designated standard temperature.

  • 100\n,^\circ\text{C}: Boiling point of water.

  • 20\n,^\circ\text{C} - 25\n,^\circ\text{C}: Room temperature.

  • 37\n,^\circ\text{C}: Human body temperature.

Precision, Accuracy, and Measurement Uncertainty

• Data Consistency Definitions:

  • Accuracy: Data that is correct and consistent with the true or accepted value.

  • Precision: Data points that are consistent with each other upon repeated measurements.

• Degree of Uncertainty in Measurement:

  • EVERY MEASUREMENT HAS A DEGREE OF UNCERTAINTY.

  • Estimated Digits:

  • The last decimal place written down in any measurement is always an estimate (usually recorded as $5$ or estimated to the last digit).

Significant Digits (Sig Figs) Rules and Calculations

• Definition:

  • Significant digits are numbers obtained by proper measuring techniques.

• Rules for Determining Significant Digits:

  • Non-Zero Numbers: All non-zero numbers are always significant.

  • Middle Zeros: Zeros situated between non-zero numbers are always significant.

  • Trailing Zeros: Trailing zeros are only significant if an explicit decimal point is present in the number.

  • Leading Zeros: Leading zeros are never significant.

• Trailing Zeros Context Example:

  • Comparison: 250\n,m versus 25\n,m

  • Significance Explanation: In 250\n,m, the trailing zero is not significant, indicating that it represents a broader, less precise range compared to a value with an explicit decimal.

• Calculations using Significant Digits:

  • Addition and Subtraction: The answer must be rounded to match the least number of decimal places found in any measurement in the problem.

  • Multiplication and Division: The answer must be rounded to match the least total number of significant figures found in any measurement in the problem.

  • Rounding Practice: ALWAYS round at the very end of multi-step calculations.

Scientific Notation and Unit Conversions

• Scientific Notation Principles:

  • Purpose: A standardized form for writing extremely large or extremely small numbers.

  • Powers of 10: Utilizes powers of 10 to represent magnitude.

  • Decimal Placement: The decimal point must always be placed directly behind the first non-zero number.

  • Determining the Exponent: The power of 10 corresponds to the exact number of places the decimal point moved to reach its position.

  • Exponent Sign Rules:

  • A number that began as a large value ($\ge 10$) has a positive exponent.

  • A number that began as a small value (< 1) has a negative exponent.

• Unit Conversions and Dimensional Analysis:

  • Dimensional Analysis: A problem-solving method for converting units using an equivalent expression as a conversion factor.

  • Equivalents: An expression establishing two equal quantities in different units.

  • Conversion Factors: Ratios constructed from equivalent expressions used to systematically change units.

  • Reference Note: A conversion chart is provided on the test.