Chemistry Study Guide – Unit Analysis, Conversions, Density, Significant Figures, and Temperature Scales

Vocabulary flashcards covering key terms from unit analysis/conversions, density, significant figures, and temperature scales.

Conversion factor method (unit analysis)

A problem‑solving approach that treats units like algebraic variables and uses ratios equal to 1 to cancel unwanted units and reach the desired unit.

Plan a path (unit analysis)

Decide the starting unit and the target unit and lay out the sequence of conversions to reach the target.

Mole

A counting unit in chemistry equal to 6.022 × 10^23 particles; used to relate mass and amount of substance.

Avogadro's number

6.022 × 10^23 particles per mole; used to convert between moles and molecules.

Molar mass

Mass of one mole of a substance in g/mol (e.g., H2O = 18.02 g/mol); used to convert grams to moles.

1 in = 2.54 cm

Exact length conversion between inches and centimeters.

1 L = 1.06 qt

Volume conversion between liters and quarts.

Density

Mass per unit volume (D = m/V); common units include g/mL, g/cm^3, and kg/m^3.

g/mL

Density unit used for liquids (grams per milliliter).

g/cm^3

Density unit used for solids (grams per cubic centimeter).

kg/m^3

Density unit in the SI system (kilograms per cubic meter).

1 cm^3 = 1 mL

Cubic centimeter is equal to a milliliter in volume.

Significant figures

Digits that convey precision in a measurement; rules govern how many digits are kept in results.

Addition/Subtraction: least precise decimal place

When adding or subtracting, round to the least precise decimal place among the quantities.

Multiplication/Division: least number of sig figs

When multiplying or dividing, round to the smallest number of significant figures among the factors.

Scientific notation

Expresses numbers as a value between 1 and 10 multiplied by a power of ten; helps clarify significant figures.

Temperature scales (Celsius, Fahrenheit, Kelvin)

Celsius: 0°C freezes, 100°C boils; Fahrenheit: 32°F freezes, 212°F boils; Kelvin: absolute zero scale (K = °C + 273.15); relationships include F = (C × 9/5) + 32 and C = (F − 32) × 5/9; -40°C = -40°F.