Some Basic Concepts of Chemistry

Measurement (1.3, 1.4): name the 5 key ideas

• SI base units (1.3.1) • Mass, volume, density, temperature • Scientific notation (1.4.1) • Significant figures (1.4.2) • Dimensional analysis (1.4.3)

What is SI base units (1.3.1)?

Seven base units; mole and kelvin matter most in chemistry.

What is conservation of mass (1.5.1)?

Lavoisier: total mass before and after a reaction is equal.

Laws of chemical combination (1.5): name the 5 key ideas

• Conservation of mass (1.5.1) • Definite proportions (1.5.2) • Multiple proportions (1.5.3) • Gay-Lussac's gaseous volumes (1.5.4) • Avogadro's law (1.5.5)

What is atomic mass unit (1.7.1)?

One twelfth of a C-12 atom, 1.66 x 10^-24 g.

Explain why: “One mole = 6.022 x 10^23”

Same count as atoms in exactly 12 g of carbon-12.

Atomic and molecular masses (1.7): name the 3 key ideas

• Atomic mass unit (1.7.1) • Average atomic mass (1.7.2) • Molecular and formula mass (1.7.3, 1.7.4)

What are mole ratios from coefficients?

Coefficients give mole and gas-volume ratios, not mass ratios.