Unit 1: Atomic Structure and Properties - Composition of Mixtures & Combustion Analysis

Flashcards covering matter classification, substances, mixtures, law of definite proportions, elemental analysis, and combustion analysis formulas/concepts from Unit 1 Topic 1.4.

Substance

A sample of matter with distinct properties and a composition that does not vary from sample to sample.

Element

A substance which cannot be decomposed to simpler substances.

Compound

A substance which can be decomposed to simpler substances because it is made up of more than one element.

Law of Definite Proportions

The principle that a compound has a definite composition, meaning the relative number of atoms of each element in the compound is the same in any sample.

Homogeneous Mixture

A mixture that has the same, or a uniform, composition throughout the sample; also called a solution.

Heterogeneous Mixture

A mixture that can vary in composition throughout a sample.

Solution

Another name for a homogeneous mixture.

Elemental Analysis

An analytical process whose purpose is to determine the quantity of a particular element within a molecule or material.

Qualitative Elemental Analysis

A form of elemental analysis focused on determining what elements are present or the presence of a particular element.

Quantitative Elemental Analysis

A form of elemental analysis focused on determining how much of a particular or each element is present.

Mass Percentage

A common result of elemental analysis calculated as $\text{Mass Percentage} = \left(\frac{\text{Mass of substance}}{\text{Total mass of mixture}}\right) \times 100$.

Combustion Analysis

A technique in which compounds containing $C$, $H$, and $O$ are routinely analyzed through complete combustion in excess oxygen within a furnace.

Oxygen Mass Determination in Combustion Analysis

Calculated by taking the difference between the mass of the original compound used and the total combined mass of $C$ and $H$, because mass of $O$ cannot be determined directly from products due to $O_2$ being added during combustion.