Chemical Mass and Empirical Formulas

Flashcards covering key concepts related to molecular mass, combustion analysis, and determination of empirical formulas from combustion data.

Molecular Mass (MM)

Sum of all atomic masses of all atoms in the molecule.

Formula Mass (FM)

Used for ionic compounds; sum of all atomic masses of all atoms in a formula unit.

Avogadro’s Number (NA)

6.0221367×10^23; the number of atoms in 12 g of carbon-12.

Molar Mass

Mass of 1 mole of substance; numerically equal to molecular mass (MM).

Mass % of Element A

(mass of element A in compound / mass of compound) × 100%.

Combustion Analysis

A method for determining percent composition of elements in a compound by burning the sample and measuring the products.

Pseudoformula

An initial formula representation used during the process of determining the empirical formula.

Fractional Subscripts

Subscripts in a pseudoformula that are not whole numbers; may need to be multiplied to obtain whole numbers.

Determining Empirical Formula

Process that involves converting masses of combustion products to moles, forming a pseudoformula, and adjusting subscripts.

CO2 Absorber

A device used to capture carbon dioxide produced during combustion analysis.

H2O Absorber

A device used to capture water produced during combustion analysis.