Chemistry Fundamentals: Qualitative vs Quantitative, Measurements, Significant Figures, and Matter & Mixtures

A set of practice flashcards covering qualitative vs quantitative measurements, color quantification, SI units, Avogadro's number, molecular thinking, states of matter, pure substances vs mixtures, significant figures rules, and related concepts from the lecture.

What is the main difference between qualitative and quantitative measurements?

Qualitative describes non-numeric properties (color, texture, hot/cold) while quantitative uses numbers and units to quantify observations.

How can color be expressed quantitatively in chemistry?

Color can be quantified using numerical representations like hex codes, RGB, or CMYK values.

In chemistry, what does the symbol K stand for in temperature scales?

Kelvin, the absolute temperature scale with absolute zero as its zero point.

List the SI base units commonly used in chemistry and their symbols.

Mass: kilogram (kg); Length: meter (m); Time: second (s); Temperature: Kelvin (K); Electric current: ampere (A); Amount of substance: mole (mol).

What is Avogadro's number and what does it represent?

6.022 x 10^23; the number of particles in one mole of a substance.

What is the aim of thinking at the molecular level in chemistry class?

To relate macroscopic observations (like heat and color) to the underlying molecular constituents (atoms and molecules) and their behavior.

What are the three fundamental states of matter discussed in the notes?

Solid, liquid, and gas.

What is a pure substance?

A substance with a fixed composition that cannot be separated into different substances by physical means; examples include elements and compounds.

What is an element?

A pure substance consisting of only one type of atom.

What is a compound?

A substance formed from two or more elements chemically bonded in fixed proportions.

What is the 'uncertain digit' in a measurement?

The last digit of a measurement, which is uncertain due to measurement limitations and indicates precision.

Are counted quantities considered exact numbers with unlimited significant figures?

Yes. Counted quantities are exact and have unlimited significant figures.

How should exact conversion factors like 1 inch = 2.54 cm affect sig figs in calculations?

Exact numbers have unlimited sig figs and do not limit the precision of the calculation.

What is the rule for significant figures when adding or subtracting?

The result should be reported with the same number of decimal places as the measurement with the fewest decimal places.

What is the rule for significant figures when multiplying or dividing?

The result should have as many significant figures as the measurement with the fewest significant figures among the operands.

What is a homogeneous versus a heterogeneous mixture?

A homogeneous mixture has uniform composition throughout (e.g., salt water); a heterogeneous mixture has visibly different components (e.g., blue copper sulfate with rock salt).