Unit 7 Chemical Quantities Lecture Notes

These flashcards cover key vocabulary and concepts from Unit 7: Chemical Quantities, including the mole, Avogadro's number, molar mass, STP, and chemical formulas.

Mole ($mol$)

A unit that represents a certain number of particles, similar to how a dozen represents 12.

Representative Particles

The types of units matter is composed of, specifically atoms, molecules, or ions (formula units for whole compounds).

Avogadro’s number

The number of particles in a mole, equal to $6.02 \times 10^{23}$ particles.

Molar Mass

The mass, in grams, of one mole of any substance.

Standard Temperature and Pressure (STP)

The conditions under which $1.0\,mol$ of any gas occupies $22.4\,L$, defined as $273\,K$ and $1\,atm$.

Molar Volume

The volume of $22.4\,L$ occupied by energy of $1.0\,mol$ of any gas at STP.

Density of a gas formula tại STP

The calculation $\text{Density} = \frac{\text{molar mass}}{22.4\,L}$, expressed in units of $g/L$.

Percent Composition

The relative amounts of the elements in a compound, calculated as $\frac{\text{mass of element}}{\text{mass of compound}} \times 100\%$.

Empirical Formula

A formula that provides the lowest whole number ratio of the atoms of the elements in a compound.

Molecular Formula

The actual chemical formula of a compound, which can be found by multiplying the empirical formula by a whole number derived from the molar mass of the compound divided by the molar mass of the empirical formula.

Molar Mass of $H_2O$

Sum of the atomic masses of its components ($2+16$), equal to $18.0\,g$.

Molar Mass of $C_6H_{12}O_6$

Calculated as $6\times(12) + 12 + 6\times(16)$, totaling $180.0\,g$.