Chemistry and Measurement Fundamentals

A set of vocabulary flashcards based on lecture questions regarding density, temperature scales, unit conversions, and the scientific method.

Density

The ratio of an object's mass to its volume, measured in units such as $\text{g/mL}$ or $\text{g/cm}^3$. For example, urine with a density of $1.08\,\text{g/mL}$ has a mass of $135\,\text{g}$ for a $125\,\text{mL}$ sample.

Kelvin ($\text{K}$)

The absolute temperature scale used in science. It is calculated by adding $273$ to the Celsius temperature (e.g., $1672^\circ\text{C}$ is equivalent to $1945\,\text{K}$).

Volume Conversion (Gallons to Liters)

A conversion where $1\,\text{gal} = 3.785\,\text{L}$. Therefore, a barrel containing $42.0\,\text{gallons}$ of oil is equal to $159\,\text{L}$.

Percent Volume ($\%\text{ v/v}$)

The ratio of the volume of a solute to the total volume of the solution, multiplied by $100$. For instance, a solution with $375\,\text{mL}$ of water in a total volume of $630\,\text{mL}$ ($255\,\text{mL}$ ethanol + $375\,\text{mL}$ water) is $59.5\,\%$ water.

Significant Digits (Leading Zeros)

Zeros at the beginning of a number (e.g., in $0.00405$) are not significant; this number has three significant digits.

Significant Digits (Trailing Zeros)

Zeros at the end of a number after a decimal point are significant. For example, $0.05000$ has four significant digits and $53.410$ has five.

Scientific Notation

A method of expressing very large or small numbers using powers of $10$, such as expressing $4,264,000\,\text{m}$ as $4.264 \times 10^6\,\text{m}$.

Water Displacement

A method to find the volume of an irregular solid by measuring the rise in liquid level in a graduated cylinder. The density of the object is its mass divided by the change in volume ($V_{\text{final}} - V_{\text{initial}}$).

Micro ($\mu$)

A metric prefix representing the factor $10^{-6}$. One micrometer ($1\,\mu\text{m}$) is equal to $1 \times 10^{-6}\,\text{m}$.

Average Kinetic Energy

A molecular property directly related to temperature; it decreases as a substance cools (e.g., when ice goes from $273\,\text{K}$ to $263\,\text{K}$).

Theory

A consistent, tested explanation of known observations within the scientific method.

Mass vs. Weight

Mass is an intrinsic property of an object that remains constant regardless of location (e.g., Earth vs. Moon), whereas weight changes depending on gravitational force.

Kilojoule ($\text{kJ}$) to Joule ($\text{J}$) Conversion

A unit conversion where $1\,\text{kJ} = 1000\,\text{J}$. Thus, $35\,\text{kJ}$ is equivalent to $3.5 \times 10^4\,\text{J}$.